SR510 SR510m

User Manual: SR510

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MODEL SR510

LOCK-IN AMPLIFIER

1290-D Reamwood Avenue

Sunnyvale, CA 94089 U.S.A.

Phone: (408) 744-9040 • Fax: (408) 744-9049

Email: info@thinkSRS.com • www.thinkSRS.com

Stanford Research Systems, Inc.

Revision: 3.4 (11/2013)

TABLE OF CONTENTS

Condensed Information

SAFETY and Preparation for use 1

Symbols 2

Specifications 3

Front Panel Summary 5

Abridged Command List 6

Status Byte Definition 7

Configuration Switches 7

Guide to Operation

Front Panel 8

Signal Inputs 8

Signal Filters 8

Sensitivity 8

Dynamic Reserve 9

Status Indicators 9

Display Select 9

Output 9

Expand Function 9

Rel Function 9

Offset 10

Time Constants 10

Noise Measurements 10

Reference Input and Trigger Levels 11

Phase Controls 11

Power Switch 12

Local/Remote Operation 12

Default Settings 12

Rear Panel 13

AC Power 13

GPIB (IEEE-488) Connector 13

RS232 Interface 13

Signal Monitor Output 13

Pre-Amp Connector 13

A/D Inputs and D/A Outputs 13

Ratio Feature 13

Internal Oscillator 13

Guide to Programming

Communications 15

Command Syntax 15

Status LED's 15

RS232 Echo Feature 16

Try-out with an ASCII Terminal 16

Command List 17

Status Byte 20

Errors 20

Reset Command 20

Trouble-Shooting Interface Problems 21

Common Hardware Problems 21

Common Software Problems 21

RS232 Interface

Introduction to the RS232 21

Data Communications Equipment 22

Wait Command 22

Termination Sequence 22

GPIB (IEEE-488) Interface

Introduction to the GPIB 22

GPIB Capabilities 22

Response to Special GPIB commands 22

Serial Polls and SRQ's 23

Echo Mode using the RS232 23

Using Both the RS232 & GPIB 23

Lock-in Technique

Introduction to Lock-in Amplifiers 24

Measurement Example 24

Understanding the Specifications 25

Shielding and Ground Loops 25

Dynamic Reserve 26

Current Input 26

Auto-Tracking Bandpass Filter 26

Notch Filters 27

Frequency Range 27

Noise Measurements 27

Output Filters 27

Ratio Capability 27

Computer Interface 27

Internal Oscillator 27

SR510 Block Diagram

Block Diagram 28

Signal Channel 29

Reference Channel 29

Phase-Sensitive Detector 29

DC Amplifier and System Gain 29

Microprocessor System 29

Circuit Description

Introduction 30

Signal Amplifier 30

Current Amplifier 30

Notch Filters 30

Bandpass Filter 30

Reference Oscillator 31

PSD, LP Filters and DC Amplifier 31

Analog Output 31

A/D's 31

D/A's 32

Expand 32

Front Panel 32

Microprocessor Control 32

RS232 Interface 32

GPIB Interface 32

Power Supplies 33

Internal Oscillator 33

Calibration and Repair

Introduction 34

Multiplier Adjustments 34

Amplifier and Filter Adjustments 34

CMRR Adjustment 34

Line Notch Filter Adjustment 35

2xLine Notch Filter Adjustment 35

Repairing Damaged Front-End 35

Appendix A: Noise Sources and Cures

Johnson Noise 36

'1/f' Noise 36

Noise Spectrum 36

Capacitive Coupling 37

Inductive Coupling 37

Ground Loops 38

Microphonics 38

Thermocouple Effect 38

Appendix B: RS232

Simplest Case Using the RS232 39

Using Control Lines 39

Baud Rates 39

Stop Bits 40

Parity 40

Voltage Levels 40

'Eavesdropping' 40

Appendix C: GPIB

Introduction to the GPIB 41

Bus Description 41

Appendix D: Program Examples

IBM PC, Microsoft Basic, via RS232 42

IBM PC, Microsoft Fortran, via RS232 43

IBM PC, Microsoft C, via RS232 45

IBM PC, Microsoft Basic, via GPIB 47

HP-85, HP Basic, via HPIB 49

Documentation

Part Numbering and Locations 50

Parts List, Main Assembly 51

Parts List, Internal Oscillator 65

Parts List, Miscellaneous 66

Parts List, Front Panel 67

Schematic Diagrams 71

Safety and Preparation for Use

***CAUTION***: This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR set for

the wrong applied ac input-source voltage or if the wrong fuse is installed.

LINE VOLTAGE SELECTION

The SR510 operates from a 100V, 120V, 220V, or

240V nominal ac power source having a line

frequency of 50 or 60 Hz. Before connecting the

power cord to a power source, verify that the LINE

VOLTAGE SELECTOR card, located in the rear

panel fuse holder, is set so that the correct ac input

voltage value is visible.

Conversion to other ac input voltages requires a

change in the fuse holder voltage card position and

fuse value. Disconnect the power cord, open the

fuse holder cover door and rotate the fuse-pull lever

to remove the fuse. Remove the small printed circuit

board and select the operating voltage by orienting

the printed circuit board to position the desired

voltage to be visible when pushed firmly into its slot.

Rotate the fuse-pull lever back into its normal

position and insert the correct fuse into the fuse

holder.

LINE FUSE

Verify that the correct line fuse is installed before

connecting the line cord. For 100V and 120V, use a

1 Amp fuse and for 220V and 240V, use a 1/2 Amp

fuse.

LINE CORD

This instrument has a detachable, three-wire power

cord with a three-contact plug for connection to both

the power source and protective ground. The

protective ground contact connects to the accessible

metal parts of the instrument. To prevent electrical

shock, always use a power source outlet that has a

properly grounded protective-ground contact.

OPERATE WITH COVERS IN

PLACE

To avoid personal injury, do not remove the

product covers or panels. Do not operate the

product without all covers and panels in place.

WARNING REGARDING USE

WITH PHOTOMULTIPLIERS

It is relatively easy to damage the signal inputs if

a photomultiplier is used improperly with the

lock-in amplifier. When left completely

unterminated, a PMT will charge a cable to a

few hundred volts in a very short time. If this

cable is connected to the lockin, the stored

charge may damage the front-end transistors.

To avoid this problem, provide a leakage path of

about 100 KΩ to ground inside the base of the

PMT to prevent charge accumulation.

SR510 Specification Summary

General

Power 100, 120, 220, 240 VAC (50/60 Hz); 35 Watts Max

Mechanical 17" x 17" x 3.5" (Rack Mount Included) 12 lbs.

Warranty Two years parts and labor.

Signal Channel

Inputs Voltage: Single-ended or True Differential

Current: 10

6 Volts/Amp

Impedance Voltage: 100 MΩ + 25 pF, ac coupled

Current: 1 kΩ to virtual ground

Full Scale Voltage: 100 nV (10 nV on expand) to 500 mV

Sensitivity Current: 100 fA to 0.5 µA

Maximum Voltage: 100 VDC, 10 VAC damage threshold

Inputs 2 VAC peak-to-peak saturation

Current: 10 µA damage threshold

1 µA ac peak-to-peak saturation

Noise Voltage: 7 nV/√Hz at 1 kHz

Current: 0.13 pA/√Hz at 1 kHz

Common Mode Range: 1 Volt peak; Rejection: 100 dB dc to 1KHz

Above 1KHz the CMRR degrades by 6 dB/Octave

Gain Accuracy 1% (2 Hz to 100KHz)

Gain Stability 200 ppm/°C

Signal Filters 60 Hz notch, -50 dB (Q=10, adjustable from 45 to 65 Hz)

120 Hz notch, -50 dB (Q=10, adjustable from 100 to 130 Hz))

Tracking bandpass set to within 1% of ref freq (Q=5)

Dynamic Reserve 20 dB LOW (1 µV to 500 mV sensitivity)

40 dB NORM (100 nV to 50 mV sensitivity)

60 dB HIGH (100 nV to 5 mV sensitivity)

Bandpass filter adds 20 dB to dynamic reserve

Line Notch filters increase dynamic reserve to 100 dB

Reference Channel

Frequency 0.5 Hz to 100 kHz

Input Impedance 1 MΩ, ac coupled

Trigger SINE: 100 mV minimum, 1Vrms nominal

PULSE: ±1 Volt, 1 µsec minimum width

Mode Fundamental (f) or 2nd Harmonic (2f)

Acquisition Time 25 Sec at 1 Hz

6 Sec at 10 Hz

2 Sec at 10 kHz

Slew Rate 1 decade per 10 S at 1 kHz

Phase Control 90° shifts

Fine shifts in 0.025° steps

Phase Noise 0.01° rms at 1 kHz, 100 msec, 12 dB TC

Phase Drift 0.1°/°C

Phase Error Less than 1° above 10Hz

Demodulator

Stability 5 ppm/°C on LOW dynamic reserve

50 ppm/°C on NORM dynamic reserve

500 ppm/°C on HIGH dynamic reserve

Time Constants Pre: 1msec to 100 sec (6 dB/Octave)

Post: 1sec, 0.1 sec, none (6 dB/Octave) or none

Offset Up to 1X full scale (10X on expand)

Harmonic Rej -55 dB (bandpass filter in)

Outputs & Interfaces

Outputs X (RcosØ), X Offset, Noise

Output Meter 2% Precision mirrored analog meter

Output LCD Four digit auto-ranging LCD display shows same values as the analog meters

Output BNC ±10 V output corresponds to full scale input

<1Ω output impedance

Reference LCD Four digit LCD display for reference phase shift or frequency

RS232 Interface controls all functions. Baud rates from 300 to 19.2 K

GPIB Interface controls all functions. (IEEE-488 Std)

A/D 4 BNC inputs with 13 bit resolution (±10.24 V)

D/A 2 BNC outputs with 13 bit resolution (±10.24 V)

Ratio Ratio output equals 10X output divided by the Denominator input.

Internal Oscillator Range: 1 Hz to 100 kHz, 1% accuracy

Stability: 150 ppm/°C

Distortion: 2% THD

Amplitude: 1% accuracy, 500 ppm/°C stability

Front Panel Summary

Signal Inputs Single Ended (A), True Differential (A-B), or Current (I)

Signal Filters Bandpass: Q-of-5 Auto-tracking filter (In or Out)

Line Notch: Q-of-10 Notch Filter at line frequency (In or Out)

2XLine Notch: Q-of-10 Notch Filter at twice line frequency (In or Out)

Sensitivity Full scale sensitivity from 100 nV to 500 mV RMS for voltage inputs

or from 100 fA to 500 nA RMS for current inputs.

Dynamic Reserve Select Dynamic Reserve Stability Sensitivity Ranges

LOW 20 dB 5 ppm 1 µV to 500 mV

NORM 40 dB 50 ppm 100 nV to 50 mV

HIGH 60 dB 500 ppm 100 nV to 5 mV

Status Indicators OVLD Signal Overload

UNLK PLL is not locked to the reference input

ERR Illegal or Unrecognized command

ACT RS232 or GPIB interface Activity

REM Remote mode: front panel has been locked-out

Display Select X Signal Amplitude at the selected phase (AcosØ)

OFST Display the offset which is being added to the signal output

NOISE Compute and display the noise on the signal

Analog Meters Displays Signal, Offset, or Noise as a fraction of full scale

Output LCD's Displays Signal, Offset, or Noise in absolute units

Output BNC's Output follows Analog Meter, ± 10 V for ± full scale

Expand Multiplies the Analog Meter and Output voltage by a factor X1 or X10.

REL Set the Offset to null the output: subsequent readings are relative readings.

Offset Enables or Disables Offset, and allows any offset (up to full scale) to be entered.

Time Constants Pre-filter has time constants from 1 mS to 100 S (6 dB/Octave)

Post-filter has time constants of 0, 0.1 or 1.0 S (6 dB/Octave)

ENBW Equivalent Noise Bandwidth. Specifies the bandwidth when making Noise

measurements. (1Hz or 10 Hz ENBW)

Reference Input 1 MΩ Input, 0.5 Hz to 100 KHz, 100 mV minimum

Reference Trigger Trigger on rising edge, zero crossing, or falling edge

f/2f Mode PLL can lock to either X1 or X2 of the reference input frequency

Phase Controls Adjust phase in smoothly accelerating 0.025° steps, or by

90° steps. Press both 90° buttons to zero the phase.

Reference LCD Display reference phase setting or reference frequency

Power Switch Instrument settings from the last use are recalled on power-up

Abridged Command List

A Return the ‘REL’ Status

A0 Turn the ‘REL’ off

A1 Turn the ‘REL’ on

B Return Bandpass Filter Status

B0 Take out the Bandpass Filter

B1 Put in the Bandpass Filter

C Return the Reference LCD Status

C0 Display the Reference Frequency

C1 Display the Reference Phase Shift

D Return Dynamic Reserve Setting

D0 Set DR to LOW range

D1 Set DR to NORM range

D2 Set DR to HIGH range

En Return Expand Status

En,0 Turn Expand off

En,1 Turn Expand on

F Return the Reference Frequency

G Return the Sensitivity Setting

G1 Select 10 nV Full-Scale

... (G1-G3 with SRS preamp only)

G24 Select 500 mV Full-Scale

H Return Preamp Status (1=installed)

I Return the Remote/Local Status

I0 Select Local: Front panel active

I1 Select Remote: Front panel inactive

I2 Select Remote with full lock-out

J Set RS232 End-of-Record to <cr>

Jn,m,o,p Set End-of-record to n,m,o,p

K1 Simulates Key-press of button #1

... (see un-abridged command list)

K32 Simulates Key-press of button #32

L1 Return Status of Line Notch Filter

L1,0 Remove Line Notch Filter

L1,1 Insert Line Notch Filter

L2 Return Status of 2XLine Filter

L2,0 Remove 2XLine Notch Filter

L2,1 Insert 2XLine Notch Filter

M Return the f/2f Status

M0 Set reference mode to f

M1 Set reference mode to 2f

N Return the ENBW setting

N0 Select 1 Hz ENBW

N1 Select 10 Hz ENBW

O Return Offset Status

O0 Turn off Offset

O1,v Turn on Offset, v = offset

P Return the Phase Setting

Pv Set the Phase to v. Abs(v) < 999 deg

Q Return the value shown on the Output

LCD

R Return the trigger mode

R0 Set the trigger for rising edge

R1 Set the trigger for + zero crossing

R2 Set the trigger for falling edge

S Return the display status

S0 Display X = AcosØ

S1 Display Offset setting

S2 Display Noise

T1 Return pre-filter setting

T1,1 Set the pre-filter TC to 1 mS

...

T1,11 Set the pre-filter TC to 100 S

T2 Return the post-filter setting

T2,0 Remove post filter

T2,1 Set the post filter TC to 0.1 S

T2,2 Set the post filter TC to 1.0 S

V Return the value of the SRQ mask

Vn Set the SRQ Mask to the value n

(See the Status Byte definition)

W Return the RS232 wait interval

Wn Set RS232 wait interval to nX4mS

Xn Return the voltage at the rear panel

analog port n. (n from 1 to 6)

X5,v Set analog port 5 to voltage v

X6,v Set analog port 6 to voltage v

Y Return the Status Byte value

Yn Test bit n of the Status Byte

Z Reset to default settings and cancel

all pending command

Status Byte Definition

Bit Meaning

0 Magnitude too small to calculate

phase

1 Command Parameter is out-of-range

2 No detectable reference input

3 PLL is not locked to the reference

4 Signal Overload

5 Auto-offset failed: signal too large

6 SRQ generated

7 Unrecognized or illegal command

Configuration Switches

There are two banks of 8 switches, SW1 and

SW2, located on the rear panel. SW1 sets the

GPIB address and SW2 sets the RS232

parameters. The configuration switches are read

continuously and any changes will be effective

immediately.

SW1:GPIB Mode Switches

Bit Example Function

1 } up GPIB Address Switches

2 } up Address 0 to 30 allowed

3 } up 'up' for bit = 1

4 } down 'down' for bit = 0

5 } up (Most Significant Bit)

6 down 'down' to echo on RS232

(normally 'up')

7 up Not Used

8 up Not Used

If the GPIB mode switches are set as shown in the

example column above, then the lockin will be

addressed as GPIB device #23, and all GPIB

commands and data will be echoed over the

RS232 for de-bugging purposes.

SW2:RS232 Mode Switches

Bit 1 Bit 2 Bit 3 Baud Rate

up up up 19200

down up up 9600

up down up 4800

down down up 2400

up up down 1200

down up down 600

up down down 300

Bit Setting Explanation

4 up Odd parity

down Even parity

5 up No parity

down Parity enabled

6 up No echo (for computer)

down Echo mode (for terminal)

7 up Two stop bits

down One stop bit

8 unused

Eight data bits are always sent, regardless of the

parity setting. The most significant bit is always

zero.

Example: Bit 1 'down' and all others 'up' for

RS232 communication at 9600 baud, no parity,

two stop bits, and no echo or prompts by the

SR510.

SR510 Guide to Operation

Front Panel

The front panel has been designed to be almost

self-explanatory. The effect of each keypress is

usually reflected in the change of a nearby LED

indicator or by a change in the quantity shown on

a digital display. This discussion explains each

section of the front panel, proceeding left to right.

Signal Inputs

There are three input connectors located in the

SIGNAL INPUT section of the front panel. The

rocker switch located above the B input selects

the input mode, either single-ended, A, differential,

A-B, or current, I.

The A and B inputs are voltage inputs with 100

MΩ, 25 pF input impedance. Their connector

shields are isolated from the chassis ground by

10Ω. These inputs are protected to 100V dc but

the ac input should never exceed 10V peak. The

maximum ac input before overload is 1V peak.

The I input is a current input with an input

impedance of 1 KΩ to a virtual ground. The

largest allowable dc current before overload is 1

µA. No current larger than 10 mA should ever be

applied to this input. The conversion ratio is 106

V/A, thus, the full scale current sensitivities range

from 100 fA to 500 nA with a max ac input before

overload of 1 µA peak. You should use short

cables when using the current input.

Signal Filters

There are three user selectable signal filters

available; a line frequency notch, a 2X line

frequency notch, and an auto-tracking bandpass.

Each of the filters has a pair of indicator LED's and

a function key located in the SIGNAL FILTERS

section of the front panel. Pressing a key will

toggle the status of the appropriate filter. The

status of each filter is displayed as IN, filter active,

or OUT, filter inactive.

The notch filters have a Q of 10 and a depth of at

least 50 dB. Thus, the line frequency notch is 6

Hz wide and the 2X line notch has a width of 12

Hz. Both of these filters can increase the dynamic

reserve up to 50 dB at the notch frequencies. The

achievable reserve is limited by the maximum

allowable signals at the inputs. The notch

frequencies are set at the factory to either 50 Hz

or 60 Hz. The user can adjust these frequencies.

(See the Maintenance and Repair section for

alignment details.) These filters precede the

bandpass filter in the signal amplifier.

The bandpass filter has a Q of 5 and a 6 dB roll off

in either direction. Thus, the pass band (between

70% pass points) is always equal to 1/5th of the

center frequency. The center frequency is

continually adjusted to be equal to the internal

demodulator frequency. When the reference

mode is f, the filter tracks the reference. When the

mode is 2f, the filter frequency is twice the

reference input frequency. The center frequency

tracks as fast as the reference oscillator can slew

and may be used during frequency scans. The

bandpass filter adds up to 20 dB of dynamic

reserve for noise signals outside the pass band,

and increases the harmonic rejection by at least

13dB. (2nd harmonic attenuated by 13 dB, higher

harmonics attenuated 6dB/octave more.) If not

needed to improve the dynamic reserve or the

harmonic rejection then the filter should be left

OUT.

Sensitivity

The sensitivity is displayed as a value (1-500) and

a scale (nV, µV, mV). When using the current

input, which has a gain of 106 V/A, these scales

read fA, pA, and nA. The two keys in the

SENSITIVITY section move the sensitivity up and

down. If either key is held down, the sensitivity will

continue to change in the desired direction four

times a second.

The full scale sensitivity can range from 100 nV to

500 mV. The sensitivity indication is not changed

by the EXPAND function. The EXPAND function

increases the output sensitivity (Volts out /volts in)

as well as the resolution of the digital output

display.

Not all dynamic reserves are available at all

sensitivities. If the sensitivity is changed to a

setting for which the dynamic reserve is not

allowed, the dynamic reserve will change to the

next setting which is allowed. Sensitivity takes

precedence over the dynamic reserve. The

sensitivity range of each dynamic reserve is

shown below.

Dynamic Reserve Sensitivity Range

LOW 1 µV through 500 mV

NORM 100 nV through 50 mV

HIGH 100 nV through 5 mV

Dynamic Reserve

The dynamic reserve (DR) is set using the keys in

the DYNAMIC RESERVE section. The reserve is

displayed by the three indicator LED's, HIGH,

NORM, LOW. Only those dynamic reserve

settings available for the sensitivity are allowed

(see above table). For example, when the

sensitivity is 500 mV, the DR will always be LOW.

The dynamic reserve and output stability of each

setting are shown below.

Setting Dynamic Reserve Output Stability

(ppm/°C)

LOW 20 dB 5

NORM 40 dB 50

HIGH 60 dB 500

Since a higher DR results in degraded output

stability, you should use the lowest DR setting for

which there is no overload indication. Note that

using the Bandpass Filter provides about 20dB of

additional DR and so allows you to operate with a

lower DR setting.

Status

There are five STATUS LED's.

OVLD indicates a signal overload. This condition

can occur when the signal is too large, the

sensitivity is too high, the dynamic reserve is too

low, the offset is on, the expand is on, the time

constant is not large enough, or the ENBW is too

large.

UNLK indicates that the reference oscillator is not

phase locked to the external reference input. This

can occur if the reference amplitude is too low, the

frequency is out of range, or the trigger mode is

incorrect for the reference signal waveform.

ERR flashes when an error occurs on one of the

computer interfaces, such as an incorrect

command, invalid parameter, etc.

ACT indicates activity on the computer interfaces.

This LED blinks every time a character is received

by the SR510 or transmitted by the SR510.

REM indicates that the unit is in the remote state

and that the front panel controls are not operative.

There are two remote states. The Remote-With-

Lockout will not allow any inputs from the front

panel. The Remote-Without-Lockout command

allows you to return the front panel to operation by

pressing the DISPLAY UP key.

Diplay Select

The keys in the DISPLAY section select the

parameter to be displayed on the output meters

and the output on the OUTPUT BNC connector.

The displayed parameter is indicated by one of the

three LED’s and can be either the demodulator

output (X), the offset (OFST), or the rms noise

(NOISE). When displaying NOISE, the equivalent

noise bandwidth (ENBW) is selected in the TIME

CONSTANT section.

Output

The analog output is available at the OUTPUT

BNC. The input signal equal to the selected full

scale sensitivity will generate a ±10V output when

the EXPAND function is off. With the EXPAND on,

the output is multiplied by 10, effectively

increasing the full scale sensitivity by 10. The

ouptut impedance is <1Ω and the output current is

limited to 20 mA.

The analog meter always displays the OUTPUT

voltage. Accuracy is 2% of full scale.

The OUTPUT LCD display provides a read-out of

the displayed parameter in real units. The scale of

the displayed quantity is indicated by the three

scale LED's to the right of the display. This read-

out auto ranges and will reflect the sensitivity

added when the EXPAND function is on.

Expand

The output EXPAND is toggled by pressing the

key in the EXPAND section. The expand status is

indicated by the X10, expand on, and the X1,

expand off, LED's.

REL Function

The relative (auto-zero) function is toggled by the

key in the REL section. Every time the rel status

LED is turned ON the offset value is set to minus

the value of the X output, thus zeroing the X

output. This function will work even if X is not the

currently displayed parameter. If the output is

greater than 1.024 times full scale, the REL

function will not be able to zero the output and the

ON LED will blink. The offset value will then be set

to its max value. If NOISE is being displayed when

the REL function is turned on, the noise ouptut will

require a sew seconds to settle again.

If the manual OFFSET in ON when the REL

function is turned on, the manual OFFSET will be

turned OFF before the auto zero is done.

The REL function and the manual OFFSET are

both ways to enter the offset value. When the REL

function is turned off using the REL key the offset

is turned off but the value is not lost. If the manual

OFFSET is now turned ON, the offset will be that

set by the REL function.

Offset

The OFFSET section controls the manual

OFFSET. The offset is turned ON and OFF using

the upper key in the OFFSET section. When the

offset is ON, the lower two keys are used to set

the amount of offset. A single key press will

advance the offset by 0.025% of full scale. If the

key is held down, the offset advances in larger and

larger increments, the largest increment being

10% of full scale. When the offset is turned OFF

the applied offset returns to zero but the offset

value is not lost. The next press of the upper

offset key (returns to ON) sets the offset to the

previously entered value.

If an attempt is made to advance the offset value

beyond full scale, the OFFSET ON LED will blink.

An offset up to 1.024 times the full scale sensitivity

may be entered. When the expand is on, this is

10X the full scale output.

If the REL function is ON when the manual

OFFSET is turned ON, the REL function is turned

OFF but the offset value remains the same. The

OFFSET keys may now be used to adjust this

offset value.

Note that the offsets (either manual offset or those

generated by the REL function) represent a

fraction of the full scale reading, and so their

absolute value will change when the sensitivity

scale is changed. A signal which has been nulled

by an offset will not be nulled when the sensitivity

scale is changed. The analog meter and the

output BNC indicate the same value given by the

equation:

Vout = 10Ae(AvVicosØ+Vos)

where...

Ae= 1 or 10 per the Expand setting

Av= 1/Sensitivity

Vi= magnitude of the signal

Ø = phase between signal & reference

Vos = offset (fraction of FS < 1.024)

Time Constant

There are two post demodulator low pass filters,

labeled PRE and POST. The PRE filter precedes

the POST filter in the output amplifier. Each filter

provides 6 dB/oct attenuation.

The PRE filter time constant ranges from 1 mS to

100 S and is selected by the two keys below the

PRE filter indicator LED's. Holding down either

key will advance the time constant twice a second

in the desired direction.

The POST filter time constant can be set to 1 S or

0.1 S, or can be removed altogether, NONE, using

the two keys below the ENBW indicators. When

set to NONE, the total attenuation is that of the

PRE filter, or 6 dB/oct. When the POST filter is 1

S or 0.1S, the total attenuation is 12 dB/oct for

frequency components beyond the larger of the

POST and PRE filter bandwidths (reciprocal time

constant).

Noise

When the DISPLAY is set to NOISE, none of the

PRE and POST indicator LED's are on. Instead,

one of the two ENBW indicators will be on,

showing the Equivalent Noise Bandwidth of the

rms noise calculation. The ENBW is set using the

keys below the ENBW indicator LED's (same keys

as used to set the POST filter). The PRE filter

keys do nothing in this case. Pressing the upper

key when the bandwidth is already 1 Hz will reset

the rms noise average (output) to zero, restarting

the calculation. Likewise with pressing the lower

key when 10 Hz is already selected.

The noise is the rms deviation of the output within

a 1 or 10 Hz equivalent noise bandwidth about the

reference frequency. A dc output does not

contribute to the noise, the noise is determined

only by the ac 'wiggles' at the output. By

measuring the noise at different frequencies, the

frequency dependence of the noise density can be

found. This usually has the form of vnoise ~ 1/f.

The noise computation assumes that the noise

has a Gaussian distribution (such as Johnson

noise). Since the computation takes many time

constants (reciprocal bandwidth), the noise output

should be allowed to approach a steady value

before a reading is taken. For the 1 Hz ENBW,

this time is on the order of 15 to 30 seconds; for

the 10 Hz ENBW, the output stabilizes much

faster. The noise output will vary slightly since

there will always be noise variations that are slow

compared to the bandwidth. Any DC component

in the output will not contribute to the noise.

However, a large DC output will cause the noise

computation to initially rise to a large value before

approaching the final answer. As a result, the

computation will take longer to settle.

To obtain a value for the noise density, the noise

reading should be divided by the square root of

the ENBW. Thus, when the ENBW is 1 Hz, the

noise output is the noise density, and when the

ENBW is 10 Hz, the noise density is the noise

output divided by √10. For example, if the input

noise is measured to be 7 nV with the ENBW set

to 1 Hz, the noise density is 7 nV/√Hz. Switching

the ENBW to 10 Hz results in a faster

measurement and a reading of 22 nV on the

output. The noise density is 22 nV/√10 Hz or 7

nV/√Hz. At frequencies » 10 Hz, the noise

density should be independent of the ENBW.

Reference and Trigger Level

The REFERENCE INPUT BNC is located in this

section. The input is ac coupled and the

impedance is 1 MΩ. The dc voltage at this input

should not exceed 100 V and the largest ac signal

should be less than 10 V peak. The three

indicators above the input BNC display the

TRIGGER MODE. The single key above the input

BNC is used to select the TRIGGER MODE.

If the center TRIGGER MODE LED is on, the

mode is SYMMETRIC and the reference oscillator

will lock to the positive zero crossings of the ac

reference input. The ac signal must be symmetric

(e.g. sine wave, square wave, etc.) and have a

peak to peak amplitude greater than 100 mV. A

signal with 1 Vrms amplitude is recommended.

The phase accuracy of the reference channel is

specified for a 1Vrms sinewave in the symmetric

trigger mode.

If the upper TRIGGER MODE LED is on, the

mode is POSITIVE. The trigger threshold is +1V

and the reference oscillator will lock to the positive

going transitions of the reference input. This

mode triggers on the rising edges of a TTL type

pulse train. The pulse width must be greater than

1 µS.

If the lower TRIGGER MODE LED is on, the mode

is NEGATIVE. The trigger threshold is -1V and

the reference oscillator will lock to the negative

going transitions of the reference input. This

mode triggers on a negative pulse train or on the

falling edges of a TTL type pulse train

(remembering that the input is ac coupled). The

pulse width must be greater than 1 µS.

Above the TRIGGER MODE indicators are the

REFERENCE MODE LED's. The key below the

REFERENCE MODE indicators toggles between f

and 2f. When the MODE is f, the lock-in will

detect signals at the reference input frequency.

When the MODE is 2f, the lock-in detects signals

at twice the reference input frequency. In either

case, the reference oscillator has a maximum

frequency of 100 KHz, thus, when in the 2f mode,

the reference input frequency may not exceed 50

KHz.

The REFERENCE DIGITAL DISPLAY shows

either the reference oscillator frequency or

phaseshift. The displayed parameter toggles

between the two whenever the SELECT key is

pressed. The appropriate scale indicator below

the display will be on. It is useful to check the

frequency display to verify that the lock-in has

correctly locked to your reference. The reference

frequency is measured to 1 part in 256 resolution.

Phase Controls

The phase shift between the reference oscillator

and the reference input is set using the four keys

in the PHASE section. The two keys below the

FINE label increment the phase setting in small

amounts. A single key press will change the

phase by 0.025 degrees in the desired direction.

Holding the key down will continue to change the

phase with larger and larger steps with the largest

step being 10 degrees. The two 90° keys are

used to change the phase by 90 degree

increments. The upper key will add 90 degrees

and the lower key will subtract 90 degrees.

Holding both keys down at once sets the phase

shift back to zero. The REFERENCE DIGITAL

DISPLAY automatically displays the phase

whenever any of the PHASE keys are pressed.

The phase ranges from -180 degrees to +180

degrees and is the phase delay from the reference

input signal.

Power

This is the instrument's POWER switch. When the

power is turned off, the front panel settings are

retained so that the instrument will return to the

same settings when the power is next turned on.

When the power is turned on, the OUTPUT

DIGITAL DISPLAY will show the SERIAL

NUMBER of the instrument and REFERENCE

DISPLAY shows the model number of the

instrument. All displays return to normal after 2

seconds.

Local and Remote

When the instrument is programmed via the

computer interface to be in the REMOTE state

WITHOUT LOCK-OUT, the DISPLAY UP key will

return the instrument to LOCAL front panel

control. If the instrument is in the REMOTE WITH

LOCK-OUT state, no front panel key will return the

status to LOCAL. In this case, a RETURN TO

LOCAL command must be sent over the computer

interface or the power must be turned off and back

on.

Defaults

If the REL key is held down when the POWER is

turned on, the instrument settings will be set to the

defaults shown below instead of the settings in

effect when the power was turned off.

Parameter Setting

BANDPASS OUT

LINE OUT

LINE X 2 OUT

SENSITIVITY 500 mV

DYN RES LOW

DISPLAY X

EXPAND OFF

REL OFF

OFFSET OFF (value=0)

PRE TIME CONSTANT 100 mS

POST TIME CONSTANT 0.1 S

ENBW 1 Hz

REFERENCE MODE f

TRIGGER MODE SYMMETRIC

REFERENCE DISPLAY FREQUENCY

PHASE 0°

Whenever default values are used at power up,

the red ERR LED will turn on for about 3 seconds.

If the ERR LED is on when the instrument is

powered on without the LOCAL key down, then

the instrument is ignoring the retained settings.

This can be due to a low battery.

SR510 Guide to Operation

Rear Panel

AC Power

The ac line voltage selector card, line fuse, and

line cord receptacle are located in the fuse holder

at the left side of the rear panel. See the section,

Preparation for Use at the front of this manual for

instructions on setting the ac voltage selector and

choosing the correct fuse.

GPIB Connector

The SR530 has an IEEE 488 (GPIB) interface built

in. The GPIB address is set using SW1 located to

the right of the interface connectors. Refer to

page 7 for switch setting details.

RS232 Connector

The SR530 has an RS232 interface. The

connector is configured as a DCE. The baud rate,

parity, stop bits, and echo mode are selected

using SW2 located to the right of the interface

connectors. Refer to Page 7 for switch setting

details.

Signal Monitor Output

This BNC provides the buffered output of the

signal amplifiers and filters. This is the signal just

before the demodulator. The output impedance is

<1Ω. When a full scale input is applied, the peak-

to-peak amplitude at this output is 20 mV, 200 mV

or 2 V for dynamic reserve settings of high, norm,

and low, respectively.

Preamp Connector

This 9 pin "D" connector provides power and

control signals to external peripherals such as pre-

amplifiers. The available power is described

below.

Pin Voltage Current Available

1 +20 100 mA

2 +5 10 mA

6 -20 100 mA

7 Signal ground

8 Digital ground

General Purpose A/D and D/A

There are four analog input ports, labeled X1

through X4. These inputs may be digitized and

read via the computer interfaces. The range is -

10.24 V to +10.24 V and the resolution is 2.5 mV.

The input impedance is 1 MΩ. A digitization can

be performed in about 3 mS but the result may

take longer to transmit over the interface being

used.

There are two analog output ports, labeled X5 and

X6. The voltages at these ports may be

programmed via the computer interfaces. The

range is -10.24 V to +10.24 V and the resolution is

2.5 mV. The output impedance is <1Ω and the

output current is limited to 20 mA.

Ratio

Output X5 is the ratio output when not

programmed by the computer interface or set via

the front panel. X5 becomes the ratio output

whenever the unit is turned on.

The voltage at X5 is the ratio of the detected

signal output, X, to the analog voltage at port X1.

An output of 10 V corresponds to a ratio of 1. The

ratio is computed by digitizing the demodulator

output and the voltage at port X1 and then taking

the ratio. The resolution is 0.0025 V. For best

accuracy, the sensitivity should be set to provide

at least a 50% full scale signal and the analog

denominator (X1) should be 5V or greater. The

ratio is updated approximately every 1.5 mS. For

the Ratio feature to work, the voltage at the

denominator input must exceed 40 mV.

Internal Oscillator

The INTERNAL OSCILLATOR is a voltage

controlled oscillator with a sine wave output . To

use the oscillator as the reference source, connect

the REF OUTPUT on the rear panel to the REF

INPUT on the front panel. The REF OUTPUT is a

1 Vrms sine wave. The SINE OUTPUT may be

used as the stimulus to the experiment. The SINE

OUTPUT can be set to three amplitudes, 1 V, 100

mV, and 10 mV (rms) using the amplitude switch.

The output impedance is 600Ω. The AMP CAL

screw adjusts the amplitude.

The oscillator frequency is controlled by the VCO

INPUT voltage. A voltage from 0V to 10V will

adjust the frequency according to the VCO

RANGE selected. Three ranges are available, 1

Hz/V, 100 Hz/V, and 10 KHz/V. The input

impedance is 10 kΩ. The FREQUENCY CAL

screw adjusts the frequency.

There are four ways to set the frequency:

1) Connect X5 or X6 (D/A outputs) to the VCO

INPUT. The frequency is now controllable via the

computer interfaces by programming X5 or X6.

2) If the VCO INPUT is left open, then the

oscillator will run at the top of its range (i.e. 10 Hz,

1 KHz, or 100 KHz).

3) A 10 KΩ potentiometer may be connected from

the VCO INPUT to ground. This pot will then set

the frequency.

4) Connect the VCO INPUT to an external voltage

source which can provide 0 to 10V.

In all four cases, if the REF OUTPUT is connected

to the REFERENCE INPUT on the front panel, the

frequency may be read on the front panel

REFERENCE DIGITAL DISPLAY or via the

computer interfaces.

SR510 Guide to

Programming

The SR510 Lock-in Amplifier is remotely

programmable via both RS232 and GPIB

interfaces. It may be used with laboratory

computers or simply with a terminal. All front

panel features (except signal input selection and

power) may be controlled and read via the

computer interfaces. The SR510 can also read

the analog outputs of other laboratory instruments

using its four general purpose analog input ports.

There are also two programmable analog output

ports available to provide general purpose control

voltages.

Communicating with the SR510

Before using either the RS232 or GPIB interface,

the appropriate configuration switches need to be

set. There are two banks of 8 switches, SW1 and

SW2, located on the rear panel. SW1 sets the

GPIB address and SW2 sets the RS232

parameters. The configuration switches are read

continuously and any changes will be effective

immediately. For details on switch settings, see

page 7 at the front of this manual.

Command Syntax

Communications with the SR510 use ASCII

characters. Commands to the SR510 may be in

either UPPER or lower case.

A command to the SR510 consists of one or two

command letters, arguments or parameters if

necessary, and an ASCII carriage return (<cr>) or

line-feed (<lf>) or both. The different parts of the

command do not need to be separated by spaces.

If spaces are included, they will be ignored. If

more than one parameter is required by a

command, the parameters must be separated by a

comma. Examples of commands are:

G 5 <cr> set the sensitivity to 200 nV

T 1,4 <cr> set the pre filter to 30 mS

F <cr> read the reference frequency

P 45.10 <cr> set phase shift to 45.10°

X 5,-1.23E-1 <cr> set port X5 to -0.123 V

Multiple commands may be sent on a single line.

The commands must be separated by a semicolon

(;) character. The commands will not be executed

until the terminating carriage return is sent.

An example of a multiple command is:

G 5; T 1,4; P 45.10 <cr>

It is not necessary to wait between commands.

The SR510 has a command input buffer of 256

characters and processes the commands in the

order received. Likewise, the SR510 has an

output buffer (for each interface) of 256

characters.

In general, if a command is sent without

parameters, it is interpreted as a request to read

the status of the associated function or setting.

Values returned by the SR510 are sent as a string

of ASCII characters terminated usually by carriage

return, line-feed. For example, after the above

command is sent, the following read commands

would generate the responses shown below.

Command Response from the SR510

G <cr> 5<cr><lf>

T 1 <cr> 4<cr><lf>

P <cr> 45.10<cr><lf>

The choice of terminating characters sent by the

SR510 is determined by which interface is being

used and whether the 'echo' feature is in use. The

terminating sequence for the GPIB interface is

always <cr><lf> (with EOI). The default sequence

for RS232 is <cr> when the echo mode is off, and

<cr><lf> when the echo mode is on. The

terminating sequence for the RS232 interface may

be changed using the J command.

Note that the terminating characters are sent with

each value returned by the SR510. Thus, the

response to the command string G;T1;P<cr> while

using the RS232 non-echo mode would be

5<cr>4<cr>45.10<cr>.

Front Panel Status LED's

The ACT LED flashes whenever the SR510 is

sending or receiving characters over the computer

interfaces.

The ERR LED flashes whenever an error has

occurred, such as, an illegal command has been

received, a parameter is out of range, or a

communication buffer has exceeded 240

characters. This LED flashes for about three

seconds on power-up if the battery voltage is

insufficient to retain previous instrument settings.

The REM LED is on whenever the SR510 is

programmed to be in the remote state.

RS232 Echo and No Echo

Operation

In order to allow the SR510 to be operated from a

terminal, an echo feature has been included which

causes the unit to echo back commands received

over the RS232 port. This feature is enabled by

setting switch 6 on SW2 to the DOWN position. In

this mode, the SR510 will send line-feeds in

addition to carriage returns with each value

returned and will also send the prompts 'OK>' and

'?>' to indicate that the previous command line

was either processed or contained an error.

Operating the SR510 from a terminal is an ideal

way to learn the commands and responses before

attempting to program a computer to control the

SR510. When the unit is controlled by a

computer, the echo feature should be turned off to

prevent the sending of spurious characters which

the computer is not expecting.

Try-Out with an ASCII Terminal

Before attempting any detailed programming with

the SR510, it is best to try out the commands

using a terminal. Connect a terminal with an

RS232 port to the RS232 connector on the rear

panel of the SR510. Set the baud rate, parity, and

stop bits to match the terminal by setting SW2 per

the switch setting table given on page 7. The

echo mode should be enabled (switch 6 DOWN).

After setting SW2 and connecting the terminal,

hold down the REL key while turning the unit on.

This causes the SR510 to assume its default

settings so that the following discussion will agree

with the actual responses of the SR510. The ACT

and ERR LED's on the front panel will flash for a

second and the sign-on message will appear on

the terminal. Following the message, the prompt

'OK>' will be displayed. This indicates that the

SR510 is ready to accept commands.

Type the letter 'P' followed by a carriage return

(P<cr>). The SR510 responds by sending to the

terminal the characters 0.00 indicating that the

phase is set to 0 degrees. In general, a command

with no arguments or parameters reads a setting

of the unit. To set the phase to 45 degrees, type

the command, P45<cr>. To see that the phase

did change, use the SELECT key on the front

panel to display the phase on the REFERENCE

DIGITAL DISPLAY. Typing the phase read

command, P<cr>, will now return the string 45.00

to the terminal.

Now read the gain using the sensitivity read

command, G<cr>. The response should be 24

meaning that the sensitivity is at the 24th setting or

500 mV. Change the sensitivity by typing

G19<cr>. The sensitivity should now be 10 mV.

Check the front panel to make sure this is so.

The output of the lock-in is read by typing the

command, Q1<cr>. The response is a signed

floating point number with up to 5 significant digits

plus a signed exponent. Change the gain to 10 uV

using the G10 command. The response to the Q1

command will now be similar to the previous one

except that the exponent is different.

Attach a DC voltmeter to the X6 output on the rear

panel. The range should allow for 10V readings.

The voltage at the X6 output can be set using the

X6 command. Type X6,5.0<cr> and the X6 output

will change to 5.0V. To read this back to the

terminal, just type X6<cr>. When setting the X6

voltage, the voltage may be sent as an integer (5),

real (5.000), or floating point (0.500E1) number.

Now connect the X6 output to the X1 input (also

on the rear panel). X1 through X4 are analog

input ports. To read the voltage on X1, simply

type X1<cr>. The response 5.000 should appear

on the terminal. The analog ports X1 through X6

can be used by your computer to read outputs of

other instruments as well as to control other

laboratory parameters.

At this point, the user should experiment with a

few of the commands. A detailed command list

follows.

SR510 Command List

The first letter in each command sequence is the

command. The rest of the sequence consists of

parameters. Multiple parameters are separated by

a comma. Those parameters shown in {} are

optional while those without {} are required.

Variables m and n represent integer parameters

while v represents a real number. Parameters m

and n must be expressed in integer format while v

may be in integer, real, or floating point format.

A {n}

If n is "1", the A command causes the auto offset

routine to run. Every time an "A 1" command is

received, the auto offset function is executed. If n

is "0", then the auto offset is turned off. If n is

absent, then the auto offset status is returned.

Note that if the manual offset is on, an "A 1"

command will turn off the manual offset before

executing the auto offset function.

B {n}

If n is "1", the B command sets the bandpass filter

in. If n is "0", the bandpass filter is taken out. If n

is absent, then the bandpass filter status is

returned.

C {n}

If n is "1", the C command sets the reference LCD

display to show the phase setting. If n is "0", the

LCD will display the reference frequency. If n is

absent, the parameter being displayed (frequency

or phase) is returned. Note that the P and F

commands are used to read the actual values of

the phase and frequency.

D {n}

If n is included, the D command sets the dynamic

reserve. If n is absent, the dynamic reserve

setting is returned.

n Dyn Res

0LOW

1NORM

2 HIGH

Note that not all dynamic reserve settings are

allowed at every sensitivity.

E {n}

If n is "1", the E command turns the output expand

on. If n is "0", the expand is turned off. If n is

absent, the expand status is returned.

The F command reads the reference frequency.

For example, if the reference frequency is 100 Hz,

the F command returns the string "100.0". If the

reference frequency is 100.0 kHz, the string

"100.0E+3" is returned. The F command is a read

only command.

G {n}

If n is included, the G command sets the gain

(sensitivity). If n is absent, the gain setting is

returned.

n Sensitivity

1 10 nV

2 20 nV

3 50 nV

4 100 nV

5 200 nV

6 500 nV

71 µV

82 µV

95 µV

10 10 µV

11 20 µV

12 50 µV

13 100 µV

14 200 µV

15 500 µV

16 1 mV

17 2 mV

18 5 mV

19 10 mV

20 20 mV

21 50 mV

22 100 mV

23 200 mV

24 500 mV

Note that sensitivity settings below 100 nV are

allowed only when a pre-amplifier is connected.

The H command reads the pre-amplifier status.

If a pre-amplifier is connected, a "1" is returned,

otherwise, a "0" is returned. The H command is a

read only command.

I {n}

If n is included, the I command sets the remote-

local status. If n is absent, the remote-local status

is returned.

n Status

0 Local: all front panel keys are operative

1 Remote: front panel keys are not

operative. The display up key returns the

status to local.

2 Lock-out: front panel keys are not

operative. No key returns the status to

local. Another I command is needed to

return to local.

When using the GPIB interface, the REN, LLO,

and GTL commands are not implemented. The I

command is used by both interfaces to set the

remote-local status.

J {n1,n2,n3,n4}

The J command sets the RS232 end-of-record

characters sent by the SR510 to those specified

by the ASCII codes n1-n4. If no argument is

included, the end-of-record sequence returns to

the default (a carriage return), otherwise, up to

four characters may be specified. The end-of-

record required by the SR510 when receiving

commands is not affected.

K n

The K command simulates a front panel key

press. The effect is exactly the same as pressing

the selected key once. The parameter n is

required.

nKey

1 Post Time Constant Up

2 Post Time Constant Down

3 Pre Time Constant Up

4 Pre Time Constant Down

5 Offset Up

6 Offset Down

7 Zero Phase (Simultaneous 90¡ Up and

Down)

8 Line Notch Filter

9 Bandpass Filter

10 Line X 2 Notch Filter

11 Relative (Auto Offset)

12 Offset (On/Off)

13 Expand

14 Local (Display Up when REMOTE)

15 Reference Trigger Mode

16 Reference Mode (f/2f)

17 Degrees Up

18 Degrees Down

19 Quad Up

20 Quad Down

21 Select Display (f/phase)

22 Sensitivity Up

23 Sensitivity Down

24 Dyn Res Up

25 Dyn Res Down

26 Display Up

27 Display Down

L m {,n}

The L command sets and reads the status of the

line notch filters. If m is "1", then the 1X line

notch is selected, if m is "2", the 2X line notch is

selected. The parameter m is required. If n is "1",

the L command sets the selected filter in. If n is

"0", the selected filter is taken out. If n is absent,

the status of the selected filter is returned.

M {n}

If n is "1", the M command sets the reference

mode to 2f. If n is "0", the reference mode is set

to f. If n is absent, the reference mode is returned.

N {m}

If m is "1", the N command sets the ENBW to 10

Hz. If m is "0", the ENBW is set to 1 Hz. If m is

absent, the ENBW setting is returned.

O {n} {,v}

If n is "1", the O command turns the offset on. If n

is "0", the offset is turned off. If n is absent, the

offset status (on or off) is returned. (The value of

the offset is read using the S and Q commands.)

If n is included, then v may also be sent. v is the

offset value up to plus or minus full scale in units

of volts. For example, to offset half of full scale on

the 100 µV sensitivity, v should be "50.0E-6" or an

equivalent value. However, if the sensitivity is

then changed to 200 µV, the offset is now half of

the new full scale or 100 µV. When the sensitivity

is changed, the offset is retained as a constant

fraction of full scale rather than as a voltage

referred to the input. The expand function will, on

the other hand, preserve the value of the offset as

an input referred voltage. Once a value of v is

sent, the offset may be turned off and on without

losing the offset value by using the O command

without the v parameter. Note that if the auto

offset is on, an "O 1" command will turn the auto

offset off and turn the manual offset on without

changing the actual offset value.

P {v}

If v is absent, the P command returns the phase

setting from -180 to +180 degrees. When v is

included, the phase is set to the value of v up to

±999 degrees.

The Q command returns the output reading in

units of volts. For an input signal of 50 µV on a full

scale sensitivity of 100 µV, the Q command will

return the string "50.00E-6". The parameter read

is the same as that being shown on the output

display and can be changed with the S command.

R {n}

If n is included, the R command sets the reference

input trigger mode. If n is absent, the trigger

mode is returned.

n Mode

0 Positive

1 Symmetric

2 Negative

S {n}

If n is included, the S command selects the

parameter shown on the analog meter and output

digital display as well as the output BNC. If n is

absent, the parameter being displayed is returned.

n Display

1 Offset

2Noise

T m {,n}

The T command sets and reads the status of the

time constants. If m is "1", the pre time constant

is selected, if m is "2", the post time constant is

selected. The parameter m is required. If n is

included, the T command sets the selected time

constant. If n is absent, the setting of the selected

time constant is returned.

n Pre Time Constant (m=1)

11mS

23mS

310mS

430mS

5 100mS

6 300mS

71S

83S

910S

10 30 S

11 100S

n Post Time Constant (m=2)

0 none

1 0.1 S

21 S

U m {,n}

The U command sets and reads the unit's ROM

calibration bytes. m is the address offset of the

byte, 0-255. If n is absent, the value of the

addressed calibration byte is returned. If n is

included, the addressed calibration byte is set to

the value of n, 0-255. The new value will be in

effect until the power is turned off or a reset

command is issued. Use of this command is not

recommended.

V {n}

If n is included, the V command sets the GPIB

SRQ (service request) mask to the value n. If n is

absent, the value of the SRQ mask is returned.

W {n}

The W command sets and reads the RS232

character wait interval. If n is included, the SR510

will wait n*4 mS between characters sent over the

RS232 interface. This allows slow computer

interfaces to keep up. n can range from 0 to 255.

If n is absent, the wait value is returned. The wait

interval is set to 6 on power-up.

X n {,v}

n designates one of the 6 general purpose analog

ports located on the rear panel. If n is 1,2,3, or 4,

the X command will return the voltage on the

designated analog input port (X1-X4) in volts. If n

is 5 or 6, then v may also be sent. If v is included,

the designated analog output port (X5 or X6) will

be set to v volts where v has the range -10.24V to

+10.24V. If v is absent, the output value of the

selected port is returned. On power-up, port X5 is

the ratio output. An "X 5" command will read the

ratio output. An "X 5" command with the

parameter v will set port X5 to v volts, overriding

the ratio output. Port X5 will return to the ratio

output on power-up or reset.

Y {n}

The Y command reads the status byte. (See

below for a definition of the Status Byte.) n

designates one bit, 0-7, of the status byte. If n is

included, the designated bit of the status byte is

returned. The bit which is read is then reset. If n

is absent, the value of the entire byte is returned

and all status bits are then reset. This status byte

may also be read over the GPIB using the serial

poll command.

The Z command causes an internal reset. All

settings return to their default values. The ERR

LED will be on for about 2 seconds to indicate that

the stored instrument settings are being ignored.

If the RS232 echo mode is on, the sign-on

message is sent over the RS232 interface.

Status Byte

The SR510 maintains an 8-bit status register

which the user may read to obtain information on

the unit's status. The status byte may be read in

two ways: by sending the Y command, which

returns the value of the byte in ASCII coded

decimal, or, when using the GPIB, by performing a

serial poll. The returned status byte reflects all of

the status conditions which have occurred since

the last time the byte was read. After the status

byte has been read, it is cleared. Thus, the status

byte should be read initially to clear all previous

conditions (especially after a power up or after

settings have been changed).

The definitions for each bit of the status byte are

given below:

Bit 0

Busy. When this bit is set, it indicates the SR510

has unprocessed commands pending on its

command queue. For RS232 communications,

this bit is always high since the Y command itself

will be an unprocessed command. This bit is not

reset when read but only when there are no

pending commands. Since the SR510 buffers

incoming commands, it is not necessary to read

this bit before sending each command.

Commands received while the SR510 is executing

a previous command are stored until all previously

received commands have been executed.

Bit 1

Command Parameter Out of Range. This bit is

set if a parameter associated with a command is

not in the allowed range.

Bit 2

No Reference. This bit is set when no reference

input is detected, either because the amplitude is

too low or the frequency is out of range.

Bit 3

Unlock. This bit is set when the reference

oscillator is not locked to the reference input. If

there is no reference input, bit 2 (no reference) will

be set but bit 3 (unlock) may not be.

Bit 4

Overload. This bit is set if there is a signal

overload. This can happen when the sensitivity is

too high, the dynamic reserve is too low, the offset

is on, or the expand is on. Overloads on the

general purpose A/D inputs or the ratio output are

not detected.

Bit 5

Auto Offset Out of Range. This bit is set if the

auto offset function cannot zero the output

because the output exceeded 1.024X full scale.

Bit 6

SRQ. This bit is high if the SR510 has generated

an SRQ on the GPIB interface. This bit is reset

after the SR510 has been serial polled. This bit is

set only for status reads via a serial poll, ie., Bit 6

always zero for the RS232.

Bit 7

Command Error. This bit is set when an illegal

command string is received.

Errors

Whenever a 'parameter out of range' or an

'unrecognized command' error occurs, the

appropriate status bits are set and the ERR LED

flashes. In addition, any commands remaining on

the current command line (up to the next <cr>) are

lost. The ERR LED will also light if any of the

internal communication buffers overflows. This

occurs when 240 characters are pending on the

command queue or output queue. The ERR LED

will go off as soon as all buffers drop below 200

characters again.

Reset

The Z command resets the unit to its default state.

The default front panel settings are listed in the

DEFAULTS section of the Guide to Operations.

In addition, the interface status returns to LOCAL,

the SRQ mask is cleared, the RS232 character

WAIT interval is set to 6, and the terminating

sequence is reset to the proper defaults.

The command and output buffers are cleared by

the Z command. Therefore, it is bad practice to

use the Z command before all previous commands

have been processed and all responses have

been received.

Trouble-Shooting Interface

Problems

If you are having difficulty getting your computer to

communicate with the SR510 look to the sections

on the RS232 and GPIB interfaces for some tips

specific to your particular interface.

An ASCII terminal is a valuable aid for debugging

interface problems. You can use it to:

1) become familiar with the SR510's command

structure,

2) see GPIB bus transactions by using the GPIB

echo mode,

3) eavesdrop on transactions when using the

RS232 interface,

4) substitute a human for the SR510 by using a

null modem cable ( to make the DTE a DCE )

and attaching the terminal to the port to which

you would normally have connected the

SR510. This allows you to test your program's

responses to inputs which you provide from

the terminal.

Common Hardware Problems include:

1) The RS232 or GPIB cables are not properly

attached.

2) The configuration switches for the RS232

characteristics or GPIB address are not set

correctly (Make sure the RS232 echo is off

when using the RS232 interface with a

computer. The GPIB with RS232 echo mode

should be off when not debugging the GPIB

interface.)

3) Your computer requires an RS232 control line

to be asserted, but your cable does not pass it

between the SR510 and the computer, or,

your computer is not asserting the DTR line on

the RS232.

Common Software Problems include:

1) You have sent the wrong command to ask for

data from the SR510. Your program will wait

forever for a response which is not going to

come. This may not be your fault; we have

seen Microsoft's Interpreted Basic on the IBM

PC occasionally send a curly bracket (ASCII

253) when it was supposed to have sent a

carriage return (ASCII 13).

2) Your computer's baud rate has been changed

and no longer matches the SR510's baud rate.

3) The initial command sent to the SR510 was

invalid due to a garbage character left in the

command queue from power-up, or, the first

character in you computer's UART is garbage,

also due to power-up. It is good practice to

send a few carriage returns to the SR510

when your program begins, and have your

program clear-out its UART at the start of your

program.

4) The SR510 is not sending the correct 'end-of-

record' marker for your computer. For

example, it appears that Microsoft's Rev 3.2

FORTRAN on the IBM PC under DOS 2.1

requires two carriage returns for an end-of-

record marker. The J command can be used

to set the SR510 end-of-record marker to 2

carriage returns. [The end-of-record marker is

that sequence which indicates that the

response is complete. From the keyboard, a

single carriage return is the end-of-record

marker.]

5) Answers are coming back from the SR510 too

fast, overwriting the end-of-record markers,

and causing the computer to hang waiting for

a complete response. In this case, the W

command can be used to slow down the

response time of the SR510 preventing

overwriting.

6) Answers are coming back from the SR510 too

slowly due to the W6 default setting for the

character interval time. Use the W command

to speed up the transmission from the SR510.

This can cause problems for the GPIB

interface if the echo mode is on (switch 6 of

SW21).

The SR510 with the RS232 Interface

The RS232 is a popular serial interface standard

for bit serial communication. Despite the

existence of the standard there are many

permutations of control lines, baud rates, and data

formats. If you do not have a lot of experience

interfacing RS232 equipment you should read

Appendix B for a description of the RS232 and

interfacing tips.

Data Communications Equipment

(DCE)

The SR510 is configured as DCE so that it may be

connected directly to a terminal. If the SR510 is to

be interfaced with another DCE device, a special

cable (sometimes referred to as a 'modem' cable)

is required. To use the RS232 interface you must

set the switches in SW2 to match your computer's

baud rate, parity, and number of stop bits. Refer

to Page 7 for details.

Wait Command

The SR510 normally waits until the RS232 'Clear

to Send' control line (CTS) is asserted before

sending characters. However, some computers

do not set and reset the CTS line, possibly

causing the SR510 to send data when the

computer is not ready to read it. The SR510 may

be 'slowed down' using the W command. Sending

'Wn' causes the unit to wait nX4 mS before

sending each character over the RS232 bus. The

command W0 sets the wait interval to zero and

results in the fastest transmission. The wait

interval is set to 6 (24 mS) on power-up.

Termination Sequences

The default RS232 termination characters are

sufficient to interface with most computers,

however, it will occasionally be necessary to send

special terminating sequences to fit the

requirements of some computers. This can be

done with the J command. The format for the

command is:

J {n1,n2,n3,n4}

where n1, n2, n3, and n4 are decimal values

between 0 and 255 corresponding to the decimal

ASCII codes of the desired termination characters.

For instance, if the desired termination sequence

is an asterisk, (ASCII 42), two carriage returns,

(ASCII 13), and a line feed, (ASCII 10), the

appropriate command is:

J 42,13,13,10

If a G command is sent requiring an answer of 24

(sensitivity = 500 mV), the SR510 would respond

with the string

24*<cr><cr><lf>

Up to four terminating characters may be specified

by the J command. If no arguments are sent with

the J command, the terminating sequence returns

to the default (echo on: <cr><lf>; echo off: <cr>).

The J command does not affect the terminating

character (<cr>) required at the end of commands

received by the SR510. It also does not affect the

terminating sequence sent with data over the

GPIB interface.

The SR510 with the GPIB

Interface

For a brief introduction to the GPIB standard,

please read Appendix C at the back of this

manual. Before using the GPIB interface you

must set the switches in SW1 per the instructions

on page 7.

GPIB Capabilities

The GPIB capabilities of the SR510 consistent

with IEEE standard 488 (1978) are shown in the

table below. Also shown are the responses of the

SR510 to some standard commands.

Code Function

SH1 Source handshake capability

AH1 Acceptor handshake capability

T5 Basic Talker, Serial Poll, Unaddressed to

talk if addressed to listen

L4 Basic Listener, Unaddressed to listen if

addressed to talk

SR1 Service request capability

PP0 No parallel poll capability

DC1 Device Clear capability

RL0 REN,LLO, GTL not implemented.

'I' command sets Remote-Local.

SR510 Response to GPIB Commands

Mnemonic Command Response

DCL Device Clear Same as Z command

SDC Selected Same as Z command

Device Clear

SPE Serial Poll Send Status Byte,

Enable & clear status byte

Because the SR510 can be controlled by an

RS232 interface as well as the GPIB, the remote-

local functions are not standard. There is no local

with lock out state. When in the local state,

remote commands are processed, even without

the REN command being issued. This is because

the RS232 interface has no provision for bus

commands and remote commands over the

RS232 interface would never be enabled.

Serial Polls and Service Requests

The status byte sent by the SR510 when it is serial

polled is the same status byte which is read using

the Y command (except for bit 6, SRQ). Of

course, when the SR510 is serial polled, it does

not encode the status byte as a decimal number.

The SR510 can be programmed to generate a

service request (SRQ) to the GPIB controller every

time a given status condition occurs. This is done

using the V{n} command. The mask byte, n (0-

255), is the SRQ mask byte. The mask byte is

always logically anded with the status byte. If the

result is non-zero, the SR510 generates an SRQ

and leaves the status byte unchanged until the

controller performs a serial poll to determine the

cause of the service request. When the unit has

been serial polled, the status byte is reset to

reflect all of the status conditions which have

occurred since the SRQ was generated.

For example, if we want to generate an SRQ

whenever there is an overload or unlock condition,

we need an SRQ mask byte equal to 00011000

binary, or 24 decimal ("V24" command). The byte

00011000 binary corresponds to the status byte

with the 'no reference' and 'unlock' status bits set.

If an overload occurs, then an SRQ will be

generated. The serial poll will return a status byte

showing SRQ and overload. If an unlock condition

occurs before the serial poll is concluded, another

SRQ will be generated as soon as the serial poll is

finished. A second serial poll will reflect the unlock

condition.

Any SRQ generated by the 'no reference, 'unlock',

'overload', and 'auto over-range' conditions will

also reset the corresponding bit in the SRQ mask

byte. This is to prevent a constant error condition

(such as no reference applied to the input) from

continually interrupting the controller. When such

an SRQ occurs, the controller should change

some parameter so as to solve the problem, and

then re-enable the SRQ mask bit again using the

V command.

GPIB with RS232 Echo Mode

It is sometimes useful when debugging a GPIB

system to have some way of monitoring exactly

what is going back and forth over the bus. The

SR510 has the capability to echo all characters

sent and received over the GPIB to its RS232 port.

This mode of operation is enabled by setting

switch 6 of SW1 to the DOWN position. The baud

rate, stop bits, and parity of the RS232 port are

still set by SW2. Of course, the RS232 port

operates at much lower speeds than the GPIB and

will slow down the GPIB data rate in this mode.

(Use the W0 command to allow the RS232

interface to run at full speed, otherwise, the GPIB

transactions may take so long that the controller

can hang.) During actual use, this mode should

be disabled.

The SR510 with BOTH Interfaces

If both interfaces are connected, commands may

be received from either interface. Responses are

always sent to the source of the request (except in

GPIB echo mode). It is unwise to send commands

from the two interfaces at the same time since the

characters from different sources can become

interleaved on the command queue and result in

'unrecognized command' errors.

The Lock-in Technique

The Lock-in technique is used to detect and

measure very small ac signals. A Lock-in amplifier

can make accurate measurements of small signals

even when the signals are obscured by noise

sources which may be a thousand times larger.

Essentially, a lock-in is a filter with an arbitrarily

narrow bandwidth which is tuned to the frequency

of the signal. Such a filter will reject most

unwanted noise to allow the signal to be

measured. A typical lock-in application may

require a center frequency of 10 KHz and a

bandwidth of 0.01 Hz. This 'filter' has a Q of 106 -

well beyond the capabilities of passive electronic

filters.

In addition to filtering, a lock-in also provides gain.

For example, a 10 nanovolt signal can be

amplified to produce a 10 V output--a gain of one

billion.

All lock-in measurements share a few basic

principles. The technique requires that the

experiment be excited at a fixed frequency in a

relatively quiet part of the noise spectrum. The

lock-in then detects the response from the

experiment in a very narrow bandwidth at the

excitation frequency.

Applications include low level light detection, Hall

probe and strain gauge measurement, micro-ohm

meters, C-V testing in semiconductor research,

electron spin and nuclear magnetic resonance

studies, as well as a host of other situations which

require the detection of small ac signals.

A Measurement Example

Suppose we wish to measure the resistance of a

material, and we have the restriction that we must

not dissipate very much power in the sample. If

the resistance is about 0.1Ω and the current is

restricted to 1 µA, then we would expect a 100 nV

signal from the resistor. There are many noise

signals which would obscure this small signal --

60Hz noise could easily be 1000 times larger, and

dc potentials from dissimilar metal junctions could

be larger still.

In the block diagram shown below we use a

1Vrms sine wave generator at a frequency wr as

our reference source. This source is current

limited by the 1 MΩ resistor to provide a 1 µA ac

excitation to our 0.1Ω sample.

Two signals are provided to the lock-in. The

1VAC reference is used to tell the lock-in the exact

frequency of the signal of interest. The lock-in's

Phase-Lock Loop (PLL) circuits will track this input

signal frequency without any adjustment by the

user. The PLL output may be phase shifted to

provide an output of cos(wrt+Ø).

The signal from the sample under test is amplified

by a high gain ac coupled differential amplifier.

The output of this amplifier is multiplied by the PLL

output in the Phase-Sensitive Detector (PSD).

This multiplication shifts each frequency

component of the input signal, ws, by the

reference frequency, wr, so that the output of the

PSD is given by:

Vpsd = cos(wr+Ø) cos(wst)

= 1/2 cos[(wr + ws)t+Ø] +

1/2 cos[(wr - ws)t+Ø]

The sum frequency component is attenuated by

the low pass filter, and only those difference

frequency components within the low pass filter's

narrow bandwidth will pass through to the dc

amplifier. Since the low pass filter can have time

constants up to 100 seconds, the lock-in can reject

noise which is more than .0025 Hz away from the

reference frequency input.

For signals which are in phase with the reference,

the phase control is usually adjusted for zero

phase difference between the signal and the

reference. This can be done by maximizing the

output signal. A more sensitive technique would

be to adjust the phase to null the signal. This

places the reference oscillator at 90 degrees with

respect to the signal. The phase control can now

be shifted by 90 degrees to maximize the signal.

Alternatively, since the phase control is well

calibrated, the phase of the signal can be

measured by adding 90 degrees to the phase

setting which nulls the signal.

Understanding the Specifications

The table below lists some specifications for the

SR510 lock-in amplifier. Also listed are the error

contributions due to each of these items. The

specifications will allow a measurement with a 2%

accuracy to be made in one minute.

We have chosen a reference frequency of 5 kHz

so as to be in a relatively quiet part of the noise

spectrum. This frequency is high enough to avoid

low frequency '1/f' noise as well as line noise. The

frequency is low enough to avoid phase shifts and

amplitude errors due to the RC time constant of

the source impedance and the cable capacitance.

The full-scale sensitivity of 100 nV matches the

expected signal from our sample. The sensitivity

is calibrated to 1%. The instrument's output

stability also affects the measurement accuracy.

For the required dynamic reserve, the output

stability is 0.1%/°C. For a 10°C temperature

change we can expect a 1% error.

A front-end noise of 7 nV/√Hz will manifest itself

as a 1.2 nVrms noise after a 10 second low-pass

filter since the equivalent noise bandwidth of a

single pole filter is 1/4RC. The output will converge

exponentially to the final value with a 10 second

time constant. If we wait 50 seconds, the output

will have come to within 0.7% of its final value.

The dynamic reserve of 60 dB is required by our

expectation that the noise will be a thousand times

larger than the signal. Additional dynamic reserve

is available by using the bandpass and notch

filters.

A phase-shift error of the PLL tracking circuits will

cause a measurement error equal to the cosine of

the phase shift error. The SR510’s 1° phase

accuracy will not make a significant contribution to

the measurement error.

Specifications for the Example Measurement

Specification Value Error

Full Scale Sensitivity 100 nV

Dynamic Reserve 60 dB

Reference Frequency 5 kHz

Gain Accuracy 1% 1%

Output Stability 0.1%/°C 1%

Front-End Noise < 7 nV/√Hz 1.2%

Output Time Constant > 10 S 0.7%

Total RMS Error 2%

Shielding and Ground Loops

In order to achieve the 2% accuracy given in this

measurement example, we will have to be careful

to minimize the various noise sources which can

be found in the laboratory. (See Appendix A for a

brief discussion on noise sources and shielding)

While intrinsic noise (Johnson noise, 1/f noise and

alike) is not a problem in this measurement, other

noise sources could be a problem. These noise

sources can be reduced by proper shielding.

There are two methods for connecting the lock-in

to the experiment: the first method is more

convenient, but the second eliminates spurious

pick-up more effectively.

In the first method, the lock-in uses the 'A' input in

a 'quasi-differential' mode. Here, the lock-in

detects the signal as the voltage between the

center and outer conductors of the A input. The

lock-in does not force A's shield to ground, rather it

is connected to the lock-in's ground via a 10½

resistor. Because the lock-in must sense the

shield voltage (in order to avoid the large ground

loop noise between the experiment and the lock-

in) any noise pickup on the shield will appear as

noise to the lock-in. For a low impedance source

(as is the case here) the noise picked up by the

shield will also appear on the center conductor.

This is good, because the lock-in's 100 dB CMRR

will reject most of this common mode noise.

However, not all of the noise can be rejected,

especially the high frequency noise, and so the

lock-in may overload on the high sensitivity

ranges.

Quasi-Differential Connection

The second method of connecting the experiment

to the lock-in is called the 'true-differential' mode.

Here, the lock-in uses the difference between the

center conductors of the A & B inputs as the input

signal. Both of the signal sources are shielded

from spurious pick-up.

With either method, it is important to minimize both

the common mode noise and the common mode

signal. Notice that the signal source is held near

ground potential in both cases. A signal which

appears on both the A & B inputs will not be

perfectly cancelled: the common mode rejection

ratio (CMRR) specifies the degree of cancellation.

For low frequencies the CMRR of 100 dB indicates

that the common mode signal is canceled to 1 part

in 105, but the CMRR decreases by about 6

dB/octave (20 dB/Decade) starting at 1KHz. Even

with a CMRR of 105, a 10 mV common mode

signal behaves like 100nV differential signal.

True-Differential Connection

There are some additional considerations in

deciding how to operate the lock-in amplifier:

Dynamic Reserve (DR) is the ratio of the largest

noise signal that the lock-in can tolerate before

overload to the full scale input. Dynamic reserve

is usually expressed in dB. Thus a DR of 60 dB

means that a noise source 1000 times larger than

a full scale input can be present at the input

without affecting the measurement of the signal. A

higher DR results in a degraded output stability

since most of the gain is DC gain after the phase

sensitive detector. In general, the lowest DR

which does not cause an overload should be used.

The Current Input has a 1 kΩ input impedance

and a current gain of 106 Volts/Amp. Currents

from 500 nA down to 100 fA full scale can be

measured. The impedance of the signal source is

the most important factor to consider in deciding

between voltage and current measurements.

For high source impedances, (>1 MΩ) or small

currents, use the current input. Its relatively low

impedance greatly reduces the amplitude and

phase errors caused by the cable capacitance-

source impedance time constant. The cable

capacitance should still be kept small to minimize

the high frequency noise gain of the current

preamplifier.

For moderate source impedances or larger

currents, the voltage input is preferred. A small

value resistor may be used to shunt the source.

The lock-in then measures the voltage across this

resistor. Select the resistor value to keep the

source bias voltage small while providing enough

signal for the lock-in to measure.

The Auto-Tracking Bandpass Filter has a Q of 5

and follows the reference frequency. The

passband is therefore 1/5 of the reference

frequency. The bandpass filter can provide an

additional 20 dB of dynamic reserve for noise

signals at frequencies outside the passband. The

filter also improves the harmonic rejection of the

lock-in. The second harmonic is attenuated an

additional 13dB and higher harmonics are

attenuated by 6 dB/octave more. You may wish to

use the bandpass filter and select a low dynamic

reserve setting in order to achieve a better output

stability. Since the processor can only set the

bandpass filter's center frequency to within 1% of

the reference frequency, this filter can contribute

up to 5° of phase shift error and up to 5% of

amplitude error when it is used. In addition, the

bandpass filter adds a few nanovolts of noise to

the front end of the instrument when it is in use.

Line Notch Filters should be used in most

measurement situations. The filters will reject

about 50 dB of line frequency noise (about a factor

of 300). If your reference frequency is one octave

away, then these filters will introduce a 10° phase

shift error, and a few percent amplitude error.

Their effect on your signal is negligible if your

reference frequency is more than two octaves

away.

The frequency range of the SR510 lock-in

amplifier extends from 0.5Hz to 100KHz. No

additional cards are required for the instrument to

cover its full frequency range. The SR510 can be

used to detect a signal at the reference frequency

or at twice the reference frequency to allow for

convenient measurement of the harmonic of the

signal.

Noise measurement is a feature which allows

direct measurement of the noise density of the

signal at the reference frequency. This is a useful

feature to assess at what frequency you should

run your experiment.

Output Filters can have one pole (6 dB per

octave) or two poles (12 dB/octave). A two-pole

filter provides a signal to noise improvement over

a single-pole filter due to its steeper roll off and

reduced noise bandwidth. Single-pole filters are

preferred when the lock-in is used in a servo

system to avoid oscillation.

In many servo applications, no output filtering is

needed. In this case, the SR510 may be modified

to reduce the output time constant to about 20 µS.

Contact the factory for details.

Ratio Capability allows the lock-in's output to be

divided by an external voltage input. This feature

is important in servo applications to maintain a

constant loop gain, and in experiments to

normalize a signal to the excitation level.

Computer Interface allows a computer to control

and to record data from the instrument. This is the

single most important feature for extending the

lock-in's capabilities and it's useful lifetime.

Measurements which are impractical without a

computer become simple when a computer is

used to coordinate various parts of the

experiment.

The Internal Oscillator provides a reference

source for the lock-in. This allows the lock-in's

frequency to be set without an additional signal

generator. It also provides a sine wave to be used

as the signal stimulus in an experiment. The

frequency may be set via the computer interface

as well as manually.

SR510 Block Diagram

Several new concepts are used to simplify the

design of SR510 lock-in amplifier. In addition to

implementing recent advances in linear integrated

circuit technology, the instrument was designed to

take full advantage of its microprocessor controller

to improve performance and to reduce cost.

As an example of the new techniques used in the

SR510, consider the harmonic rejection problem.

Previously, lock-in amplifiers used a PLL with a

square wave output. The Fourier components of

the square wave created a serious problem -- the

lock-in would respond to signal and noise at f, 3f,

5f,.ad infinitum. Quite often, one component of

this picket fence of frequencies would land on

some noise source, giving a spurious result. To

overcome this difficulty designers employed tuned

amplifiers or heterodyning techniques. All of these

'fix-ups' had drawbacks, including phase and

amplitude errors, susceptibility to drift, and card-

swapping to change frequencies.

In contrast, the SR510 detects the signal by

mixing a reference sine wave in a precision analog

multiplier. Because of the low harmonic content of

this sine wave, the instrument is insensitive to

harmonics. This approach has eliminated the

difficulty, performance compromises, and cost of

the older techniques.

The Signal Channel

The instrument has both current and voltage

inputs. The current input is a virtual ground, and

the 100 MΩ voltage inputs can be used as single-

ended or true differential inputs.

There are three signal filters. Each of these filters

may be switched 'in' or 'out' by the user. The first

filter is a line notch filter. Set to either 50 or 60 Hz,

this filter provides 50 dB of rejection at the line

frequency. The second filter provides 50 dB of

rejection at the first harmonic of the line frequency.

The third filter is an auto-tracking bandpass filter

with a center frequency tuned by the micro-

processor to the frequency of the signal. These

three filters eliminate most of the noise from the

signal input before the signal is amplified.

A high-gain ac amplifier is used to amplify the

signal before entering the phase sensitive

detector. The high gain which is available from this

programmable amplifier allows the lock-in to

operate with a lower gain in its dc amplifier. This

arrangement allows high stability operation even

when used on the most sensitive ranges.

Reference Channel

The processor controlled reference input

discriminator can lock the instrument's PLL to a

variety of reference signals. The PLL can lock to

sine waves or to logic pulses with virtually no

phase error. The PLL output is phase shifted and

shaped to provide a precision sine wave to the

phase sensitive detector.

Phase Sensitive Detector

The Phase Sensitive Detector is a linear multiplier

which mixes the amplified and filtered signal with

the reference sine wave. The difference

frequency component of the multiplier's output is a

dc signal that is proportional to the amplitude of

the signal. The low-pass filter which follows can

reject any frequency components which are more

than a fraction of a Hertz away from the signal

frequency.

DC Amplifier and System Gain

A dc amplifier amplifies the output of the low pass

filters. The total system gain is the product of the

ac and dc amplifier gains. The partitioning of the

system gain between these two amplifiers will

affect the stability and dynamic reserve of the

instrument. The output is most stable when most

of the gain is in the ac amplifier, however, high ac

gain reduces the dynamic reserve.

For the most demanding applications, the user

may specify how the system gain is partitioned.

However, with prefilters that are able to provide up

to 100 dB of dynamic reserve, and with chopper

stabilized dc amplifiers, most users will not be

concerned with just how the system gain is

allocated.

A Microprocessor Based Design

The instrument was designed to take full

advantage of its microprocessor controller. This

approach provides several key advantages...

The instrument may be interfaced to a laboratory

computer over the RS-232 and IEEE-488

interfaces. In addition to simply reading data from

the lock-in, the computer can control all of the

instrument settings with simple ASCII commands.

A key feature of the instrument is its four A/D

inputs and two D/A outputs. These analog I/O

ports may be used to read and supply analog

voltages to an experiment or measurement. All of

the input and output ports have a full scale range

of ±10.24VDC with 2.5 mV resolution and 0.05%

accuracy.

Computer control can eliminate set-up errors,

reduce tedium, and allow more complete data

recording and post measurement analysis. Also,

the computer can play an active role in the data

acquisition by adjusting gains, etc., in response to

changing measurement conditions.

The microprocessor based design eliminates

many analog components to improve

performance, reliability, and reduce cost. Each

unit is computer calibrated at the factory, and

calibration constants are placed in the instrument's

read-only memory. The SR510 has only one-fifth

of the analog trimming components that are found

in older designs.

Creative programming on the user's part can

extend the instrument's capabilities. For example,

the lab computer can instruct the lock-in to

measure the signal at zero and ninety degrees of

phase. Doing so allows both the amplitude and

phase of the signal of interest to be measured.

Circuit Description

Introduction

The SR510 Lock-in amplifier is an integrated

instrument combining state of the art analog

design with advanced microprocessor based

control and interfaces. This discussion is intended

to aid the advanced user in gaining a better

understanding of the instrument.

The SR510 has 8 main circuit areas: the signal

amplifier, the reference oscillator, the demod-

ulator, the analog output and controls, the front

panel, the microprocessor, the computer inter-

faces, and the power supplies. With the exception

of the front panel and a few pieces of hardware,

the entire lock-in is built on a single printed circuit

board. Each section is isolated from the others as

much as possible to prevent spurious signal

pickup. To aid in the location of individual

components, the first digit of each part number

generally refers to the schematic sheet number on

which it occurs. To help find the part on the circuit

board, the parts list includes a location on the

circuit board for each component.

Signal Amplifier

Assuming the input selector switch is set to a

voltage input, the signal is coupled in through

capacitors C101 and C102. The input impedance

is set by the 100 MΩ resistors R101 and R102

over the operating frequency range. Note that

R103 isolates the signal shields from the

instrument ground forcing the return signal current

back along the cable shields. The signal is then

applied differentially to the gates of Q101. Q101 is

a low noise dual JFET. The drain current through

R109 is kept constant by 2/2 U101. The other half

of U101 maintains a virtual null between the drains

of the two transistors and thus an identical current

flows through R110. Any input that would cause a

differential between the two drains is amplified by

1/2 U101 and fed back via R112 in such a way as

to reduce that differential. Since the two

transistors are at equal and constant currents,

their gate-source potentials are constant. Thus,

the fed back signal which appears at the source of

the right hand transistor exactly matches the input.

Likewise, this signal will match the input to the left

hand transistor but with the opposite sign.

Resistors R112 and R110 attenuate the fed back

signal from the output of U101 resulting in a

differential input, single ended output, fixed gain of

10 amplifier. P101 adjusts the current balance

between the two transistors and therefore their

gain match and common mode rejection.

The output of the pre-amp is scaled by resistors

R119-R122 and analog switch U103 which make

up a 1-2-5-10 attenuator. The signal is then

amplified by 2/2 U102. Input overload is sensed

through diodes D101-D104.

Current Amplifier

When the input selector is set to current, the input

to the pre-amp comes from the output of the

current to voltage converter, 1/2 U102. U102 is a

low voltage-noise bipolar op amp. Q102 serves as

an input buffer to provide low current-noise to the

input. The op amp always maintains a null at the

gates of Q102 thus providing an input impedance

of 1KΩ (R128). The input current is converted to a

voltage by R135 and the op amp. Q103

bootstraps out the summing junction capacitance

of Q102.

Notch Filters

U107 is a high Q, line frequency, notch filter which

can be switched in and out by analog switch 1/4

U106. The frequency and depth of the filter can

be adjusted with P102 and P103. Resistors R146-

R149 and switch U108 make up a selectable

attenuator. U118 is a line frequency 2nd harmonic

notch filter selected by 2/4 U106. P104 and P105

adjust the frequency and depth. The second

notch filter has a gain of 3 and its output is scaled

by U110 and resistors R156-R159. The signal

then takes two paths; to inverting amplifier U111

and to the input of the tracking bandpass filter.

U111 has the same gain as the bandpass filter.

The output of either U111 or the bandpass filter is

selected by 3/4 U112 and 4/4 U106 and amplified

by U113. U114 and U115 provide a last stage of

gain and scaling and the final output is ac coupled

and buffered by 4/4 U208.

Bandpass Filter

The bandpass filter is a three op amp state-

variable active filter. 3/4 of U201 make up the

three op amps of the standard filter. U203, U204,

and U205 are analog switches which select the

feedback capacitors for the 5 decades of

operation. The two halves of U202 are matched

transconductance amplifiers operating as

programmable, voltage controlled, current sources

which take the place of the normal, frequency

setting, resistors. A voltage proportional to the

reference frequency is converted into a current by

1/4 U208 and Q201. This current programs the

effective "resistance" of the two transconductance

amplifiers and thus, tunes the center frequency of

the filter to follow the reference. The output of the

filter is buffered by 4/4 U201. The two remaining

op amps in U208 are used to detect signal

overloads throughout the amplifier chain.

Reference Oscillator

The reference input signal is ac coupled and

buffered by U301. R378 isolates the reference

shield from the lock-in ground to prevent ground

loop currents. 1/2 U303 switches the polarity of

the reference reaching comparator U304. U305 is

a retriggerable one-shot whose output indicates a

no reference condition if no comparator pulses are

generated for 3 seconds.

U309 is a dual transconductance amplifier in a

triangle VCO configuration. U310 selects the

integrating capacitor depending on the frequency

range. The VCO frequency is determined by the

programming current through R318 and therefore

by the output voltage of U308. C306 is the phase-

locked loop low pass filter which is buffered by

U308. U307 is a programmable current source

used to charge and discharge C306. The amount

of current available to U307 is determined by the

VCO control voltage, thus, the tracking rate of the

VCO is proportional to the VCO frequency. The

triangle output is compared to a constant voltage

by U314. 1/2 U313 and 1/2 U312 select f or 2f

operation. This signal is fed back to the phase

detector U306 to be compared with the reference

output of U304. U315 compares the triangle

output with a variable voltage to generate a

square-wave signal phase-shifted from the

reference. The range of this fine phase shift

control is -5 to 95 degrees.

The output of U315 serves as the reference to a

second phase-locked loop. This second PLL uses

a similar proportional tracking triangle VCO.

Comparator U329 looks at the square wave output

of the VCO while comparator U328 detects the

zero crossings of the triangle output. 1/2 U327

selects one these comparators to feed back to the

phase detector, U316. Since the square and

triangle outputs are in quadrature, U327 selects

either an in-phase or quadrature relationship

between the two VCO's. Thus, the output of the

second VCO can be shifted from -5 to 185 deg

from the reference.

The triangle output is divided by R363 and R362

before reaching transconductance amplifier 2/2

U322. The amplitude of the triangle input to this

amplifier is enough to just saturate the input and

provide a sine wave output. 2/2 U325 then

amplifies the sine wave before it goes to the

demodulator. U324 is a comparator which

generates a square wave in-phase with the sine

output. U326 divides the frequency of the square

wave by 8 and 2/2 U327 selects the frequency of

the square wave chopper.

Demodulator and Low Pass Amplifier

Amplifier U402 and switch U401 select the polarity

of the reference sine wave. This allows phase

shifts up to 360 degrees from the reference input.

The sine wave is ac coupled by U403 and inverted

by U404. U405 selects alternating polarities of the

sine wave at the chopper frequency, f/2 or f/16.

This chopped sine wave is then multiplied by the

output of the signal amplifiers by the analog

multiplier U406. The synchronous output of the

multiplier that corresponds to the in-phase signal

is a square wave at the chopper frequency. The

output is ac coupled by U407 to remove the dc

offset of the multiplier. U408 inverts the signal and

U405 chops the square wave to recover a dc

output. U409 buffers the chopper output before

the first low pass time constant. Op amps U416

and 2/2 U402 make up the first low pass amplifier

with relays U411-U415 and U417 selecting the

time constant. The second low pass amplifier is

U419. Analog switch U418 selects the time

constant and gain. The full scale output of U418 is

5 volts.

Analog Output and Control

The dc output of the demodulator/low pass

amplifiers is passed to the reference input of

multiplying DAC U502. The DAC is programmed

with the appropriate attenuation to calibrate the

overall gain of the lock-in. Every gain setting in

each dynamic reserve is calibrated independently

and the proper attenuations are stored in the unit's

ROM.

A/D's

Analog multiplexer U504 selects the signal to be

digitized by the microprocessor. This signal can

be either the lock-in output or one of the four

independent analog inputs buffered by U501.

These general purpose inputs are located on the

rear panel of the instrument. The selected signal

is sampled and held on capacitor C502 and

buffered by 4/4 U508. The A/D conversion is done

by successive approximation using comparator

U514 to compare the sampled and held signal with

known outputs of U505, a 12 bit DAC with a

precision reference. Note that the output of U506,

an 8 bit DAC is summed with the output of U505.

This 8 bit DAC corrects for offset errors which can

accumulate as analog voltages pass through

buffers, S/H amps, and comparators. These

offsets are measured after each unit is

manufactured, and values to compensate for

these offsets are placed in the unit's ROM. The

polarity of the offset-corrected 12 bit DAC is set by

2/4 U511 and the SIGN bit yielding 13 bits of

resolution from -10.24 to +10.24 volts.

D/A's

In addition to providing reference voltages for A/D

conversion, the DAC output voltage may be

multiplexed by U507 to one of eight sample and

hold amplifiers which provide analog output and

control voltages. The microprocessor refreshes

each S/H amplifier every few milliseconds to

prevent droop. Two of these outputs are available

as general programmable outputs on the rear

panel. Two are used to program the band pass

filter and the reference oscillator phase shift. One

output is subtracted from the lock-in output in

U508 to provide a variable offset and another is

the rms noise output. Two outputs are not used.

Expand

Amplifier 3/4 U511 is the X10 expand amplifier.

U516 selects the display and output, either the

output of U511 or one of the DAC outputs.

Overload is detected by 1/4 and 2/4 U515 and the

signal monitor is driven by 3/4 U515.

Front Panel

There are 62 led's on the front panel controlled by

8 serial-in, parallel-out shift registers. All 8 shift

registers are written to simultaneously and 8

consecutive write operations are required to set

the LED's. The liquid crystal displays are

managed by the display controllers, U601 and

U602. Exclusive-or gates U605 and U606 drive

the left over segments. Octal latch U604 provides

the logic bits for these extra segments as well as

the keyboard row strobes. U603 reads the switch

closures as the rows are scanned.

Microprocessor Control

The microprocessor, U701, is a Z80A CPU

clocked at 4 Mhz. 16K bytes of firmware are

stored in the ROM, U702. U703 is a 2K byte static

RAM, backed-up by a lithium battery. A power-

down standby circuit, Q701, preserves the RAM

contents when the power is turned off. The

battery has a life of 5-10 years. The CPU has

power-up and power-down resets to prevent

erroneous execution during turn-on or short sags

in the line voltage.

U704 is a 3-channel counter. One channel

generates the baud rate for the RS232 interface

while the other two are used to measure the

frequency or period of the reference oscillator.

U709 provides a gate pulse to counter 0.

Multiplexer U708 selects whether the gate is a

single period of the reference (period

measurement) or a gate of known duration

(frequency measurement). Counter 1 is a

programmable divide by N counter whose output

is either counted for one period of the reference,

or, generates the gate pulse during which

reference pulses are counted.

I/O addresses are decoded by U705, U706, and

U707. The microprocessor controls the lock-in

functions through I/O ports U714-U721. U713

generates an interrupt to the CPU every 4 msec to

keep the microprocessor executing in real time.

RS232 Interface

The RS232 interface uses an 8251A UART, U801,

to send and receive bytes in a bit serial fashion.

Any standard baud rate from 300 to 19.2K baud

may be selected with the configuration switches.

The X16 transmit and receive clock comes from

counter 2 of U704. The RS232 interface is

configured as DCE so that a terminal may be

connected with a standard cable. When a data

byte is received by the UART, the RxRDY output

interrupts the CPU to prevent the data from being

overwritten.

GPIB Interface

The interface to the GPIB is provided by U802, an

MC68488 General Purpose Interface Adapter

(GPIA). The GPIB data and control lines are

buffered by drivers U808 and U811. Because the

GPIA uses a 1 MHz clock, wait states are provided

by U805 to synchronize I/O transactions with the 4

MHz CPU. The GPIA interrupts the CPU

whenever a GPIB transaction occurs which

requires the CPU’s response. (The GPIB address

is set by switch bank SW1.)

Power Supplies

The line transformer provides two outputs, 40VAC

and 15VAC, both center -tapped. The transformer

has dual primaries which may be selected by the

voltage selector card in the fuse holder. The

15VAC is rectified by diode bridge BR2 and

passed to 5V regulator U909. The output of U909

powers the microprocessor and its related

circuitry. The 40VAC output is half-wave rectified

by BR1 and regulated by U901 and U902 to

provide +20V and -20V. These two dc voltages

are then regulated again by 15V regulators U903-

U908. Each 15V regulator powers a separate

section of the lock-in to reduce coherent pick up

between sections. U911 and U912 provide plus

and minus 7.5V and U910 generates +5V for the

analog circuits.

Internal Oscillator

The internal oscillator is on a small circuit board

attached to the rear panel of the instrument. Local

regulators, Q1 and Q2, provide power to the

board. The VCO input is internally pulled up by

R12. This pulls the VCO input to 10V when the

VCO input is left open. 2/4 U1 translates the VCO

input voltage to provide a negative control voltage

to U2, the function generator. P3 adjusts the VCO

calibration. U2 is a sine wave generator whose

frequency range is selected by the VCO Range

switch and capacitors, C4-C6. P2 adjusts the sine

wave symmetry at low frequencies. 4/4 U1 buffers

the output of U2. P1 adjusts the amplitude of the

output sine wave. The output amplitude on the

SIne Out is selected by the amplitude switch. The

output impedance is 600Ω.

Calibration and Repair

This section details calibration of the instrument.

Calibration should only be done by a qualified

electronics technician.

********** WARNING **********

The calibration procedure requires adjusting the

instrument with power applied and so there is a

risk of personal injury or death by electric shock.

Please be careful.

Most of the calibration parameters are determined

by a computer aided calibration procedure after

burn-in at the factory. These calibration

parameters are quite stable and so will not need to

be adjusted. Calibration parameters which may

need field adjustment are detailed below.

Multiplier Adjustments

On the HIGH dynamic reserve setting, there can

be some reference frequency feedthrough. This

section describes how to null this unwanted

output.

This adjustment requires an oscilloscope and a

signal generator which can proved a 500Hz

reference signal.

Allow the unit to warm up for about 1 hour.

Reset the unit by turning it off and back on while

holding the REL key down.

Select voltage input A and connect a 50Ω

terminator or shorting plug to the A input BNC

connector. Connect the 500 Hz reference signal to

the reference input. Set the SENSITVITY to 1mV

and DYN RES to HIGH. The PRE TIME

CONSTANT should be set to 1mS and the POST

TIME CONSTANT to NONE. Connect the scope

to the OUTPUT on the front panel. Set the scope

to 2V/div and 5mS/div. Externally trigger the scope

using the reference input signal.

After about 60 seconds, the scope display should

show a 500 Hz sine wave on a 30 Hz (500/16 Hz)

square wave. Remove the 4 screws holding the

top panel on. Slide the top panel back about half

way. Using a small screwdriver, adjust P402 at

location D2 to minimize the 500 Hz output. Adjust

P403 at location C2 to minimize the 30 Hz output.

Now set the both time constants to 1S. Adjust

P404 at location F4 to zero the output. This

adjustment has a range of 20% of full scale on the

HIGH dynamic reserve setting. (2% on NORM and

0.2% on LOW). This zeroes the DC output of the

unit on all dynamic reserve ranges.

Replace the top panel.

Amplifier and Filter Adjustments

This section describes how to adjust the Common

Mode Rejection and Line notch filter frequencies.

An oscilloscope and a signal generator which can

provide an accurate line frequency and twice line

frequency signal are required.

Allow the unit to warm up for about 1 hour.

Reset the unit by turning it off and back on while

holding the REL key down.

Remove the 4 screws holding down the top panel.

Slide the panel back about halfway.

CMRR

Set the reference frequency to 100 Hz. It is

convenient to use the SYNC output of the signal

generator as the reference input if it is available.

Connect the sine output of the signal generator to

the A input and set the input selector to A. With

the SENSITIVITY at 100mV, adjust the amplitude

of the input signal to 100mV (full scale).

Now set the input selector to A-B and connect the

signal to both the A and B inputs. Set the

SENSITIVITY to 20µ

µµ

µV, the DYN RES to NORM

and the BANDPASS fiter IN. Connect the scope to

the SIGNAL MONITOR output on the rear panel.

Set the scope to AC coupled, 0.2V/div, and

10mS/div. Externally trigger the scope using the

reference input signal.

The CMRR is adjusted by the single turn

potentionmeter located at A1 under the single hole

at the front of the signal shield. (The shield is the

aluminum box on the left side of the main board).

Using a small screwdriver, carefully adjust the pot

to minimize the 100 Hz output on the scope. After

nulling the output, set the sensitivity to 2µ

µµ

µV and

null the output again.

Notch Filters

Set the reference frequency to 60.0 Hz (50.0 Hz).

It is convenient to use the SYNC output of the

signal generator as the reference input if it is

available. Connect the sine output of the signal

generator to the A input and set the input selector

to A. With the SENSITIVITY at 100mV, adjust the

amplitude of the input signal to 100 mV (full scale).

Set the LINE NOTCH to IN, the SENSITIVITY to

10mV, and the DYN RES to LOW. Connect the

scope to the SIGNAL MONITOR output on the

rear panel. Set the scope to AC coupled, 0.2V/div,

10mS/div. Trigger the scope externally using the

reference input signal.

The LINE NOTCH frequency and depth are

adjusted by the pair of 20 turn potentiometers

located under the middle two holes in the signal

shield (row 4 on the circuit board). Using a small

screwdriver, carefully adjust one pot until the line

output on the scope is minimized. Then adjust the

other pot until the output is minimized. Iterate

between the two pots until there is no further

improvement. Set the SENSITIVITY to 5mV,

2mV, and 1mV, repeating the adjustments at each

sensitivity.

Repeat this procedure using a reference

frequency of 120.0 Hz (100.0 Hz) and the LINEX2

NOTCH filter. The LINEX2 NOTCH is adjusted by

the pair of 20 turn potentiometers located under

the back two holes in the signal shield (row 5 on

the circuit board).

Replace the top panel.

Replacing the Front-End Transistors

Both the voltage and current front end transistors

(Q101 and Q102) are 2N6485 (IMF6485) dual

JFETS. These transistors are selected at the

factory to meet the noise specifications.

This section outlines their replacement procedure

in the event that they become damaged during

use.

1) Remove the AC power cord from the unit.

2) Remove top and bottom panels.

3) Release the signal shields by removing the

four screws which hold it onto the circuit

board. Be careful not to lose the nuts.

Carefully slide the shields back and then lift

them out.

4) The input transistors are located on the main

board, just behind the input selector switch.

Q101 is the voltage (A, A-B) front end, and

Q102 is the current (I) front end. Desolder

and replace the appropriate transistor.

5) Replace the signal shields. Be careful to

check that the shields do not touch any circuit

board traces around their edges.

6) Replace the top and bottom panels.

7) If Q101, the voltage front end has just been

replaced, the Common Mode Rejection needs

to be readjusted using the procedure

described in the Amplifier Adjustments

section.

Appendix A:

Noise Sources and Cures

Noise, random and uncorrelated fluctuations of

electronic signals, finds its way into experiments in

a variety of ways. Good laboratory practice can

reduce noise sources to a manageable level, and

the lock-in technique can be used to recover

signals which may still be buried in noise.

Intrinsic Noise Sources

Johnson Noise. Arising from fluctuations of

electron density in a resistor at finite temperature,

these fluctuations give rise to a mean square

noise voltage,

V2 = ∫4kT Re[Z(f)] df = 4kTR ∆f

where k=Boltzman's constant, 1.38x10-23J/°K; T

is the absolute temperature in Kelvin; the real part

of the impedance, Re[z(f)] is the resistance R; and

we are looking at the noise source with a detector,

or ac voltmeter, with a bandwidth of ∆f in Hz. For

a 1MΩ resistor,

(V2)1/2 = 0.13 µV/√Hz

To obtain the rms noise voltage that you would

see across this 1MΩ resistor, we multiply

0.13µV/√Hz by the square root of the detector

bandwidth. If, for example, we were looking at all

frequencies between dc and 1 MHz, we would

expect to see an rms Johnson noise of

(V2)1/2 = 0.13 µV/√Hz*(106 Hz)1/2 = 130 µV

'1/f Noise'. Arising from resistance fluctuations in

a current carrying resistor, the mean squared

noise voltage due to '1/f' noise is given by

V2 = A R2 I2 ∆f/f

where A is a dimensionless constant, 10-11 for

carbon, R is the resistance, I the current, ∆f the

bandwidth of our detector, and f is the frequency

to which the detector is tuned. For a carbon

resistor carrying 10 mA with R = 1k, ∆f = f = 1Hz,

we have

Vnoise = 3 µVrms

And Others. Other noise sources include flicker

noise found in vacuum tubes, and generation and

recombination noise found in semiconductors.

All of these noise sources are incoherent. Thus,

the total noise is the square root of the sum of the

squares of all the incoherent noise sources.

Non-Essential Noise Sources

In addition to the "intrinsic" noise sources listed

above there are a variety of "non-essential" noise

sources, i.e. those noise sources which can be

minimized with good laboratory practice. It is

worthwhile to look at what might be a typical noise

spectrum encountered in the laboratory

environment:

Noise Spectrum

Some of the non-essential noise sources appear

in this spectrum as spikes on the intrinsic

background. There are several ways which these

noise sources work their way into an experiment.

Capacitive Coupling. A voltage on a nearby

piece of apparatus (or operator) can couple to a

detector via a stray capacitance. Although Cstray

may be very small, the coupled in noise may still

be larger than a weak experimental signal.

Capacitive Noise Coupling

To estimate the noise current through Cstray into

the detector we have

i=C

stray dV = jwCstrayVnoise

where a reasonable approximation to Cstray can

be made by treating it as parallel plate capacitor.

Here, w is the radian frequency of the noise

source (perhaps 2 * π * 60Hz ), Vnoise is the noise

voltage source amplitude (perhaps 120 VAC). For

an area of A = (.01 m)2 and a distance of d =

0.1m, the 'capacitor' will have a value of 0.009 pF

and the resulting noise current will be 400pA. This

meager current is about 4000 times larger than the

most sensitive current scale that is available on

the SR510 lock-in.

Cures for capacitive coupling of noise signals

include:

1) removing or turning off the interfering noise

source,

2) measuring voltages with low impedance

sources and measuring currents with high

impedance sources to reduce the effect of istray,

3) installing capacitive shielding by placing both

the experiment and the detector in a metal box.

Inductive Coupling. Here noise couples to the

experiment via a magnetic field:

Inductive Noise Coupling

A changing current in a nearby circuit gives rise to

a changing magnetic field which induces an emf in

the loop connecting the detector to the

experiment. (emf = dØB/dt.) This is like a

transformer, with the experiment-detector loop as

the secondary winding.)

Cures for inductively coupled noise include:

1) removing or turning off the interfering noise

source (difficult to do if the noise is a broadcast

station),

2) reduce the area of the pick-up loop by using

twisted pairs or coaxial cables, or even twisting the

2 coaxial cables used in differential hook-ups,

3) using magnetic shielding to prevent the

magnetic field from inducing an emf (at high

frequencies a simple metal enclosure is

adequate),

4) measuring currents, not voltages, from high

impedance experiments.

Resistive Coupling (or 'Ground Loops').

Currents through common connections can give

rise to noise voltages.

Resistive Coupling

Here, the detector is measuring the voltage across

the experiment, plus the voltage due to the noise

current passing through the finite resistance of the

ground bus. This problem arises because we

have used two different grounding points which

are not at exactly the same potential. Some cures

for ground loop problems include:

1) grounding everything to the same physical

point,

2) using a heavier ground bus to reduce the

potential drop along the ground bus,

3) removing sources of large currents from ground

wires used for small signals.

Microphonics provides a path for mechanical

noise to appear as electrical noise in a circuit or

experiment. Consider the simple circuit below:

The capacitance of a coaxial cable is a function of

its geometry so mechanical vibrations will cause

the cable capacitance to vary with time. Since

C=Q/V, we have

C dV + V dC = dQ = i

dt dt dt

so mechanical vibrations will cause a dC/dt which

in turn gives rise to a current i, which will affect the

detector. Ways to eliminate microphonic signals

include:

1) eliminate mechanical vibrations,

2) tie down experimental cables so they will not

sway to and fro,

3) use a low noise cable that is designed to reduce

microphonic effects.

Thermocouple Effect. The emf created by

dissimilar metal junctions can give rise to many

microvolts of dc potential, and can be a source of

ac noise if the temperature of the junction is not

held constant. This effect is large on the scale of

many low level measurements.

Appendix B:

Introduction to the RS232

The 'RS232' is a standard for bit serial

asynchronous data communication. The standard

defines the format for data transmission, the

electrical specifications for the signal levels, and

the mechanical dimensions of connectors.

Despite the definition of a standard, there are so

many permutations of control lines, data formats,

and transmission speeds, that getting two RS232

devices to communicate usually requires some

work.

In this section, we will provide some basic

information to aid you in connecting your RS232

device to the SR510 Computer Interface.

CASE 1 - The Simplest Configuration.

In this case, one wire is used to send data from

device A to device B and another wire is used to

send data from device B to device A. Notice that

pin 2 is an output on device A and an input on

device B. (It is good practice to run the ground,

pin 7, between the devices as well). The RS232

defines two types of devices; DTE (Data Terminal

Equipment) and DCE (Data Communications

Equipment.) An RS232 port on a computer may

be either a DTE or DCE but nearly every terminal

with an RS232 port is a DTE. RS232 ports on a

computer which are intended to connect to a

modem, such as the COM1: port on the IBM PC,

are DTE. The SR530 is configured as DCE, and

so it may be directly connected to ASCII terminals

and to the COM: ports on IBM PC's and

compatibles.

As an example, consider connecting an RS232

ASCII computer terminal to the SR510 using a 2

wire link. The terminal is a DTE and the SR510 is

a DCE. To operate correctly, the SR510 and the

terminal must have the same settings for baud

rate, parity, and number of stop bits. The control

lines in the RS232 Standard, which are used to

indicate that a device is ready to accept data, must

also be connected correctly at the terminal end. If

the terminal responds to a control line, it will

believe that the SR510 is not ready to accept data

(because the line is not passed in this example)

and will therefore not send any data.

CASE 2 - RS232 with Control Lines.

The data lines are the same as in Case 1. In

addition to the data lines, there are two control

lines used:

CTS - Pin 5

"Clear to send" is a signal asserted by the DCE to

tell the DTE that the DCE is ready to receive data.

DTR - Pin 20

"Data Terminal Ready" is a signal asserted by the

DTE to tell the DCE that the DTE is ready to

receive data.

The SR510 responds to the control lines as

follows:

1) If the lines are not connected, the SR510

assumes that you are ready to receive data.

2) Data will not be transmitted from the SR510 if

the DTR line (pin 20) is low. This is useful in the

case when your program is not yet ready to

receive data. If data transmission is not

suspended, then data may be overwritten in your

computer's UART (as it is not being retrieved by

the program and so will be lost.) When this

happens, the 'over-run' flag will be set in your

computer's UART and it may be recognized by the

operating system, generating an error message

such as "I/O Device Error" (See the "W" command

in the SR510 Command List for another way to

slow data transmission.)

Baud Rate

The RS232 baud rate of the SR510 is switch

selectable from 300 to 19.2K baud (see

configuration switch setting in the front of this

manual.) 19.2K baud means that data is

transmitted at 19,200 bits/second. With one start

bit, 2 stop bits, 8 data bits, and no parity bits, each

ASCII character requires 573 µsec to be

transmitted (11bits/19.2K baud.) The typical data

string 5.1270<cr> has 7 characters, requiring 4

msec to be sent.

Stop Bits

Generally, selection of 2 stop bits will result in

fewer data transmission errors.

Parity

The Parity bit provides a check against faulty data

transfer. It is not commonly used in local data

transmission environments. If the parity option is

selected, the SR510 will transmit 8 data bits and a

parity bit, however, no parity check of incoming

data is done.

Voltage Levels

The RS232 uses bipolar voltage levels:

The control lines use positive logic. For example,

the DCE tells the DTE that it is clear to send (CTS)

by placing > +3 VDC on pin 5 of the interface.

Similarly, the DTE can tell the DCE that it is not

ready by placing -3 VDC on pin 20 (DTR) of the

interface.

The data lines, pins 2 and 3, use negative logic. A

'zero' bit is represented by a positive voltage and a

'one' bit is represented by a negative voltage. A

start bit is a positive voltage and a stop bit is a

negative voltage. Data is transmitted with the

least significant bit first. The letter 'A', which has

the ASCII code 41H (0100 0001), would appear as

follows:

If a parity option was selected, the parity bit would

be sent after the 8th data bit, but before the first

stop bit.

Final Tip

When you are trying to get the RS232 to work with

your computer, it is helpful to be able to

'eavesdrop' on the RS232 data lines going

between the SR510 and the computer. This can

be done with an ASCII RS232 terminal and the

following connector:

To test the connector, place the hook clip on pin 2

of the same connector (shorting pin 2 to pin 3.)

Now, when you type at the terminal keyboard,

data transmitted from pin 2 is received at pin 3 and

displayed on the terminal screen. To use as a

debugging tool, attach the hook clip to either pin 2

or pin 3 of the RS232 cable on the SR510 to show

either data sent from the Computer or the SR510.

The baud rate, parity, and stop bits of the terminal

must match those of the SR510 and the computer.

If your terminal has a mode which will display

control characters (such as carriage returns and

line feeds) it is helpful to operate in that mode.

A variant of the 'eavesdropping' approach is

diagrammed below:

With this cable arrangement, the ASCII terminal

can listen to the data passing in both directions.

The only drawback is that the terminal will display

garbled data if both devices transmit data at the

same time.

Appendix C:

Introduction to the GPIB

The IEEE-488 Standard specifies the voltage

levels, handshake requirements, timing, hardware

details, pinout and connector dimensions for a 16

line, bit parallel bus. Many instruments may be

connected in series to communicate over the

same cable. Because the bits are passed in

parallel, the GPIB is faster than the RS232.

The controller (generally your computer)

coordinates data transfer on the bus by

designating all participating instruments (including

itself) as either a talker or a listener. Listeners can

receive data placed on the bus by the Talker.

Devices can have the capacity to operate in either

mode. The address of each device is set by

switches in the device and must be between 0 and

30.

Bus Description

Byte Transfer Control Group. This consists of 3

negative logic lines that implement the GPIB

handshaking. The NRFD (Not Ready For Data)

line is held low by any designated listener who is

not ready to accept data. When every listener is

ready, the line goes high and the talker may

release data to the bus. After data is on the bus,

the talker pulls the DAV (Data Valid) line down. At

this point, each listener retrieves the data. Before

and during the retrieval of the data, the listener

holds the NDAC (No Data Accepted) line down.

When every listener has received the data, the

NDAC line goes high, allowing the talker to

release the DAV line high. Finally, the listener

pulls down the NDAC line until another transfer is

initiated.

Data Bus: There are eight data lines which use

negative logic and pass the bits of each byte in

parallel.

General Interface Lines: These five lines operate

independently of the handshake lines and use

negative logic.

1) The EOI (End or Identify) line is used by the

talker to designate the end of message.

2) The SRQ (Service Request) line is used by any

device to ask for service. The controller can serial

poll each device (each device returns an 8 bit

status byte) to determine who needs attention. It

can also do a parallel poll using the EOI and ATN

lines where each device is assigned a single data

line.

3) The ATN (Attention) line makes both talkers

and listeners accept information and passes

control of the DAV line to the controller. This line

is used by the controller to identify talkers and

listeners through their addresses.

4) The REN (Remote Enable) line changes the

status of an instrument from local to remote.

5) The IFC (Interface Clear) line clears the bus of

all data and activity.

Though GPIB is a very powerful interface, strict

protocol must be observed for it to operate

successfully.

Appendix D:

Program Examples

All of the program examples which follow do the

same thing, only the computer, language, or

interface is changed. The programs read the

Channel 1 and 2 Outputs and write the results to

the computer screen. In addition, the X6 analog

output port is ramped from 0 to 10V.

Program Example 1:

IBM PC, Basic, via RS232

In this example, the IBM PC's ASYNC port (known

as COM1: or AUX: to DOS users) will be used to

communicate with the SR510. Only two wires

between the IBM PC's ASYNC port and the

SR510 are needed (pins #2 & #3 of the RS232),

but pins 5,6,8 and 20 should be connected

together on the connector at the IBM end.

10 ′EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT

20 ′USING IBM PC BASICA AND THE COM1: RS232 PORT.

30 ′

40 ′

50 ′ON THE REAR PANEL OF THE SR510, SET SWITCH #1 OF SW2 DOWN

60 ′AND ALL OTHER SWITCHES IN SW2 UP. (9600 BAUD, NO PARITY)

70 ′

80 OPEN ″COM1:9600,N,8,2,CS,DS,CD″ AS #1

90 ′SET UP COM1: PORT TO 9600 BAUD, NO PARITY, 8 DATA BITS, 2 STOP BITS,

100 ′IGNORE CTS (CLEAR TO SEND), DSR (DATA SET READY),

110 ′AND CD (CARRIER DETECT).

120 ′

130 PRINT #1, ″ ″′CLEAR UART BY SENDING SPACES

140 PRINT #1,″Z″′RESET SR510

150 FOR I = 1 TO 200: NEXT I ′WAIT FOR RESET TO FINISH

160 ′

170 X = 0 ′INIT X6 OUTPUT TO ZERO

180 ′

190 PRINT #1, ″Q″′READ OUTPUT

200 INPUT #1,V1 ′INTO V1

210 ′

220 PRINT ″OUTPUT = ″;V1

230 ′

240 X =X + .0025 ′INCREMENT X6 OUTPUT BY 2.5 MV

250 IF X > 10 THEN X = 0 ′RESET X6 RAMP

260 PRINT #1, USING ″X6, ##.###″;X ′SET X6 OUTPUT VOLTAGE

270 ′

280 GOTO 190 ′LOOP FOREVER

Program Example 2:

IBM PC, Microsoft Fortran

v3.3, via RS232

Machine language routines to interface to the

COM1: RS232 port are provided in the file

RS232.OBJ found on the SR575 disk. These

routines allow for simple interfacing to the SR510

at 19.2 kbaud from FORTRAN programs.

To use these routines, the file 'for232.inc' (also on

the SR575 disk) must be 'included' in the

FORTRAN source.

Only two wires between the IBM PC's ASYNC

port and the SR530 are needed (pins #2 & #3 of

the RS232), but pins 5,6,8 and 20 should be

connected together on the connector at the IBM

end.

$storage:2

$include: ′for232.inc′

[ for 232.inc must be included to call subroutines in RS232.OBJ

[ link with RS232.OBJ (on SR565 disk)

[ RS232.OBJ defines:

[ init

[ initializes COM1: to 19.2 kbaud

[ txstr (str) str is a string terminated with ′$′

[ transmits str to COM1:

[ rxstr (str) str must be declared with length of 15 or greater

[ fills str with string received from COM1:

[ if and error occurs, nocom is called.

[ Nocom should be a FORTRAN subroutine in your program.

program test

character *20 str1,str2

[ Example program to read the SR510 outputs and ramp the

[ X6 analog output using Microsoft FORTRAN v3.3 and the

[ COM1: port. Set all switches in SW2 to UP on SR510

[ for 19.2 kbaud.

[ initialize COM1: port to 19.2 kbaud

call init

[ set character wait interval to zero

call txstr(′w0$′)

[ reset X6 to zero

x6=0.0

[ read output into string variable str1

20 call txstr(′q$′)

call rxstr(str1)

[ convert string variable into real variable v1

read (str1,1000) v1

1000 format (bn,f10.0)

[ print results to screen

write(*,2000) v1

2000 format(′ Output 1=′,G10.3)

[ ramp x6 by 2.5 mV

x6 = x6 + .0025

if (x6.gt.10) x6 = 0.0

[ make x6 command string

write (str2,3000) x6

3000 format (′x6,′,f7.3,′$′)

call txstr(str2)

[ and loop forever

goto 20

stop

end

[ ***********************************

subroutine nocom

[ in case of a timeout error, this routine runs

[ put your error handler here.

[ write(*,*) char (7)

write(*,*)′RS232 Tiemout Error!′

stop

end

Program Example 3:

IBM PC, Microsoft C v3.0,

via RS232

Machine language routines to interface to the

COM1: RS232 port are provided in the file

RS232.OBJ found on the SR565 disk. These

routines allow for simple interfacing to the SR510

at 19.2 kbaud from C programs.

To use these routines, the large model must be

used. Compile with the /AL switch and link with

RS232.OBJ.

Only two wires between the IBM PC's ASYNC port

and the SR530 are needed (pins #2 & #3 of the

RS232), but pins 5,6,8 and 20 should be

connected together on the connector at the IBM

end.

#include <stdio.h>

/* Compile with >MSC program name/AL;

link with RS232.OBJ (on SR565 disk)

RS232.OBJ defines:

init ()

Initializes COM1: to 19.2 kbaud

txstr (str);

Char *str; str must terminate with ′$′ char

Sends string str to COM1:

rxstr (str); str must be declared with 15 characters

or more length.

Fills str with string received from COM1:

If an error occurs, your procedure nocom() is called.

Nocom() must be a C procedure in your program.

Example program to read the SR510 outputs and ramp the x6 analog

Output using Microsoft C v3.0 (large model) and the COM1: port.

Set all switches in SW2 to UP on SR510 for 19.2 kbaud.

main ()

{

char str1[20], str2[20];

float v1,x;

init (); /* init COM1: port to 19.2 kbaud */

txstr (″w0$″); /* set character interval to 0 */

x = 0;

while (1)

{

txstr (″q$″); /* read channel 1 output */

rxstr (str1); /* into str1 */

sscanf (str1, ″%f″, &v1); /* scan str1 for a float variable */

x += 0.0025; /* increment x6 output by 2.5 mV */

if (x >= 10) x = 0;

sprintf (str2, ″X6,%f$″, x); /* make x6 command string */

txstr (str2); /* send x6 command */

/* print results to screen */

printf (″Output = %10.36\n″, v1);

}

/* ********************************************* */

nocom ()

/* error handling routine goes here */

{

printf(″RS232 Timeout Error\n″);

putch (7);

exit ();

}

Program Example 4:

IBM PC,Microsoft Basic,

via GPIB

This program requires the Capital Equipment

Corporation GPIB card for the IBM PC or XT. It

has firmware in ROM to interface high level

languages to the GPIB.

Subroutine calls in Microsoft BASIC are done to

memory locations specified by the name of the

subroutine. The address is relative to the segment

address specified by the DEF SEG statement

preceding CALL.

In this program, the CEC card's ROM starts at

OC0000H, the system controller's address is 21,

and the SR530 has been assigned as GPIB

address 23.

To monitor the GPIB activity with an RS232

terminal, SW1-6 should be down, and the ASCII

terminal should be attached to the rear panel

RS232 connector.

10 ′EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT

20 ′USING IBM PC BASICA AND THE CAPITAL EQUIPMENT CORP. GPIB INTERFACE CARD

30 ′

40 ′

50 ′ON THE SR510 REAR PANEL, SET SWITCHES #4 AND #6 ON SW1 TO DOWN (DEVICE

60 ′ADDRESS = 23, RS232 ECHO ON) AND SWITCH # 1 ON SW2 TO DOWN (RS232 BAUD

70 ′RATE = 9600). ALL OTHER SWITCHES SHOULD BE UP.

80 ′NOTE THAT THE RS232 ECHO IS FOR DEBUGGING AND DEMOSTRATION PURPOSES,

90 ′UNDER NORMAL CONDITIONING, SWITCH # 6 OF SW1 SHOULD BE UP SINCE THE RS232

100 ′ECHO SLOWS DOWN THE GPIB INTERFACE.

110 ′

120 DEF SEG = &HC000 ′BASE ADDRESS OF CEC CARD

130 INIT=0: TRANSMIT=3: RECV=6: ′ADDRESSES OF CEC FIRM WARE ROUTINES

140 ADDR%=21: SYS%=0 ′CONTROLLER ADDRESS

150 INZ$ = ″IFC UNT UNL MTA LISTEN 23 DATA ′Z′ 13″

160 ′

170 Q$ = ″IFC MTA LISTEN 23 DATA ′Q′ 13″

180 X6$ = ″IFC MTA LISTEN 23 DATA ′X6,″

190 LISN$ = ″IFC UNT UNL MLA TALK 23″

200 ′

210 ′

220 CALL INIT(ADDR%,SYS%) ′INIT X6 OUTPUT TO ZERO

230 CALL TRANSMIT(INZ$,STATUS%) ′RESET SR510

240 GOSUB 540 ′CHECK TRANSMIT STATUS

250 ′

260 X = 0 ′INIT X6 OUTPUT TO ZERO

270 ′

280 CALL TRANSMIT(Q$,STATUS%) ′READ OUTPUT

290 GOSUB 540

300 GOSUB 450 ′GET RESULT

310 V1 = VAL(ANS$) ′INTO V1

320 ′

330 ′

340 PRINT ″OUTPUT = ″;V1

350 ′

360 X = X + .0025 ′INCREMENT X6 OUTPUT BY 2.5 MV

370 IF X>10 THEN X 0 ′RESET RAMP

380 X$ = X6$ + STR$(X) + ″′ 13″′MAKE X6 COMMAND STRING

390 CALL TRANSMIT (X$,STATUS%) ′SET NEW X6 VOLTAGE

400 GOSUB 540

410 ′

420 GOTO 280 ′LOOP FOREVER

430 ′

440 ′GET AN ANSWER STRING FROM THE SR510

450 CALL TRANSMIT(LISN$,STATUS%) ′MAKE SR510 A TALKER

460 GOSUB 540

470 ANS$=SPACE$(10) ′INIT ANSWER STRING

480 CALL RECV(ANS$,LENGTH%STATUS%) ′READ RESULT INTO ANS$

490 GOSUB 540

500 RETURN

510 ′

520 ′

530 ′CHECK STATUS OF LAST TRANSMISSION FOR ERRORS

540 IF STATUS%=0 THEN RETURN ′STATUS OKAY

550 PRINT ″STATUS CODE = ″;STATUS%;″ ON GPIB: ERROR″

560 STOP

Program Example 5:

HP85 via GPIB

This program provides an example of an HP85

program using the GPIB interface which could be

used to control the lockin amplifier. In this

example, the SR510 should be addressed as

device #16 by setting the switch bank SW1 per the

instructions Page 7.

10 x=0

20 OUTPUT 716 ; ″Q″

30 ENTER 716 : V1

40 DISP ″OUTPUT = ″ : V1

50 X = X + .0025

60 IF X>10 THEN X+0

70 OUTPUT 716 : ″X6,″:X

80 GOTO 20

Documentation

This section contains the parts lists and

schematics for the SR510 lock-in amplifier.

The first digit of any part number can be used

to locate the scematic diagram for the part.

For example, R415 is located on sheet 4 of

the schematic diagrams.

SR510 PARTS LIST

Main Assembly PCB Parts List

NO REF. SRS part# VALUE DESCRIPTION

1. BR1 3-00062-340 KBP201G/BR-81D Integrated Circuit (Thru-hole Pkg)

2. BR2 3-00062-340 KBP201G/BR-81D Integrated Circuit (Thru-hole Pkg)

3. BT1 6-00001-612 BR-2/3A 2PIN PC Battery

4. C 101 5-00069-513 .1U Capacitor, Mylar/Poly, 50V, 5%, Rad

5. C 102 5-00069-513 .1U Capacitor, Mylar/Poly, 50V, 5%, Rad

6. C 103 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

7. C 104 5-00008-501 22P Capacitor, Ceramic Disc, 50V, 10%, SL

8. C 105 5-00002-501 100P Capacitor, Ceramic Disc, 50V, 10%, SL

9. C 106 5-00008-501 22P Capacitor, Ceramic Disc, 50V, 10%, SL

10. C 107 5-00030-520 2200U Capacitor, Electrolytic, 16V, 20%, Rad

11. C 108 5-00030-520 2200U Capacitor, Electrolytic, 16V, 20%, Rad

12. C 110 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

13. C 111 5-00081-516 1P Capacitor, Silver Mica, 500V, 5%, DM15

14. C 116 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

15. C 117 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

16. C 118 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

17. C 120 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

18. C 121 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

19. C 122 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

20. C 123 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

21. C 124 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

22. C 125 5-00030-520 2200U Capacitor, Electrolytic, 16V, 20%, Rad

23. C 126 5-00030-520 2200U Capacitor, Electrolytic, 16V, 20%, Rad

24. C 127 5-00057-512 .22U Cap, Stacked Metal Film 50V 5% -40/+85c

25. C 128 5-00057-512 .22U Cap, Stacked Metal Film 50V 5% -40/+85c

26. C 129 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

27. C 131 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

28. C 132 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

29. C 133 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

30. C 134 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

31. C 136 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

32. C 137 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

33. C 145 5-00009-501 24P Capacitor, Ceramic Disc, 50V, 10%, SL

34. C 146 5-00009-501 24P Capacitor, Ceramic Disc, 50V, 10%, SL

35. C 147 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

36. C 148 5-00017-501 47P Capacitor, Ceramic Disc, 50V, 10%, SL

37. C 201 5-00020-501 7.5P Capacitor, Ceramic Disc, 50V, 10%, SL

38. C 202 5-00109-525 150P Capacitor, Polystyrene, 50V, 5%, Ax

39. C 203 5-00048-566 .0015U Cap, Polyester Film 50V 5% -40/+85c Rad

40. C 204 5-00051-512 .015U Cap, Stacked Metal Film 50V 5% -40/+85c

41. C 205 5-00055-512 .15U Cap, Stacked Metal Film 50V 5% -40/+85c

42. C 206 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

43. C 207 5-00059-512 .47U Cap, Stacked Metal Film 50V 5% -40/+85c

44. C 208 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

45. C 209 5-00109-525 150P Capacitor, Polystyrene, 50V, 5%, Ax

46. C 210 5-00048-566 .0015U Cap, Polyester Film 50V 5% -40/+85c Rad

47. C 211 5-00051-512 .015U Cap, Stacked Metal Film 50V 5% -40/+85c

48. C 212 5-00055-512 .15U Cap, Stacked Metal Film 50V 5% -40/+85c

49. C 213 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

50. C 214 5-00059-512 .47U Cap, Stacked Metal Film 50V 5% -40/+85c

51. C 215 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

52. C 216 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

53. C 217 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

54. C 218 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

55. C 230 5-00055-512 .15U Cap, Stacked Metal Film 50V 5% -40/+85c

56. C 301 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

57. C 302 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

58. C 303 5-00009-501 24P Capacitor, Ceramic Disc, 50V, 10%, SL

59. C 304 5-00110-525 560P Capacitor, Polystyrene, 50V, 5%, Ax

60. C 305 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

61. C 306 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

62. C 307 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

63. C 308 5-00058-512 .33U Cap, Stacked Metal Film 50V 5% -40/+85c

64. C 310 5-00008-501 22P Capacitor, Ceramic Disc, 50V, 10%, SL

65. C 311 5-00008-501 22P Capacitor, Ceramic Disc, 50V, 10%, SL

66. C 312 5-00017-501 47P Capacitor, Ceramic Disc, 50V, 10%, SL

67. C 313 5-00017-501 47P Capacitor, Ceramic Disc, 50V, 10%, SL

68. C 314 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

69. C 315 5-00038-509 10U Capacitor, Electrolytic, 50V, 20%, Rad

70. C 317 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

71. C 318 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

72. C 319 5-00058-512 .33U Cap, Stacked Metal Film 50V 5% -40/+85c

73. C 320 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

74. C 321 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

75. C 322 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

76. C 323 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

77. C 324 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

78. C 325 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

79. C 326 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

80. C 327 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

81. C 328 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

82. C 329 5-00033-520 47U Capacitor, Electrolytic, 16V, 20%, Rad

83. C 330 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

84. C 331 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

85. C 332 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

86. C 333 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

87. C 334 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

88. C 335 5-00016-501 470P Capacitor, Ceramic Disc, 50V, 10%, SL

89. C 336 5-00016-501 470P Capacitor, Ceramic Disc, 50V, 10%, SL

90. C 337 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

91. C 338 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

92. C 401 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

93. C 402 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

94. C 403 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

95. C 404 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

96. C 405 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

97. C 406 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

98. C 407 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

99. C 408 5-00003-501 10P Capacitor, Ceramic Disc, 50V, 10%, SL

100. C 409 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

101. C 410 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

102. C 411 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

103. C 412 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

104. C 413 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

105. C 414 5-00053-512 .033U Cap, Stacked Metal Film 50V 5% -40/+85c

106. C 415 5-00072-513 10U Capacitor, Mylar/Poly, 50V, 5%, Rad

107. C 416 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

108. C 417 5-00060-512 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c

109. C 418 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

110. C 419 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

111. C 420 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

112. C 421 5-00013-501 33P Capacitor, Ceramic Disc, 50V, 10%, SL

113. C 422 5-00013-501 33P Capacitor, Ceramic Disc, 50V, 10%, SL

114. C 501 5-00012-501 330P Capacitor, Ceramic Disc, 50V, 10%, SL

115. C 502 5-00136-519 .01U Capacitor, Polystyrene, 50V, 5%, Rad

116. C 503 5-00007-501 220P Capacitor, Ceramic Disc, 50V, 10%, SL

117. C 504 5-00002-501 100P Capacitor, Ceramic Disc, 50V, 10%, SL

118. C 505 5-00008-501 22P Capacitor, Ceramic Disc, 50V, 10%, SL

119. C 506 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

120. C 507 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

121. C 508 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

122. C 509 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

123. C 510 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

124. C 511 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

125. C 512 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

126. C 513 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

127. C 514 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

128. C 515 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

129. C 516 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

130. C 517 5-00002-501 100P Capacitor, Ceramic Disc, 50V, 10%, SL

131. C 518 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

132. C 519 5-00049-566 .001U Cap, Polyester Film 50V 5% -40/+85c Rad

133. C 520 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

134. C 521 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

135. C 523 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

136. C 525 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

137. C 526 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20%, Z5U

138. C 527 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20%, Z5U

139. C 701 5-00007-501 220P Capacitor, Ceramic Disc, 50V, 10%, SL

140. C 702 5-00007-501 220P Capacitor, Ceramic Disc, 50V, 10%, SL

141. C 703 5-00040-509 1.0U Capacitor, Electrolytic, 50V, 20%, Rad

142. C 704 5-00040-509 1.0U Capacitor, Electrolytic, 50V, 20%, Rad

143. C 705 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

144. C 706 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

145. C 707 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

146. C 708 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

147. C 709 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

148. C 710 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

149. C 711 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

150. C 712 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

151. C 713 5-00014-501 390P Capacitor, Ceramic Disc, 50V, 10%, SL

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

152. C 714 5-00014-501 390P Capacitor, Ceramic Disc, 50V, 10%, SL

153. C 801 5-00012-501 330P Capacitor, Ceramic Disc, 50V, 10%, SL

154. C 802 5-00012-501 330P Capacitor, Ceramic Disc, 50V, 10%, SL

155. C 803 5-00012-501 330P Capacitor, Ceramic Disc, 50V, 10%, SL

156. C 804 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

157. C 805 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

158. C 806 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

159. C 807 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

160. C 808 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

161. C 809 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

162. C 810 5-00010-501 270P Capacitor, Ceramic Disc, 50V, 10%, SL

163. C 901 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

164. C 902 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

165. C 903 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

166. C 904 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

167. C 905 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

168. C 906 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

169. C 907 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

170. C 908 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

171. C 909 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

172. C 910 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

173. C 911 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

174. C 912 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

175. C 913 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

176. C 914 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

177. C 915 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

178. C 916 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

179. C 917 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

180. C 918 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

181. C 919 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

182. C 920 5-00035-521 47U Capacitor, Electrolytic, 25V, 20%, Rad

183. C 923 5-00192-542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

184. C 924 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

185. C 925 5-00046-510 2500U Capacitor, Electrolytic, 50V, 20%, Ax

186. C 926 5-00046-510 2500U Capacitor, Electrolytic, 50V, 20%, Ax

187. C 927 5-00192-542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

188. C 928 5-00192-542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

189. C 929 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

190. C 930 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

191. C 931 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

192. C 932 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

193. C 933 5-00103-524 1.0U Capacitor, Tantalum, 50V, 20%, Rad

194. C 934 5-00103-524 1.0U Capacitor, Tantalum, 50V, 20%, Rad

195. C 935 5-00036-522 6800U Cap, Electro. 25V 10% Ax, Mallory TCX

196. C 936 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

197. C 937 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

198. C 938 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

199. C 939 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

200. CN801 1-00014-160 9 PIN D Connector, D-Sub, Right Angle PC, Female

201. CN802 1-00016-160 RS232 25 PIN D Connector, D-Sub, Right Angle PC, Female

202. CN803 1-00238-161 GPIB SHIELDED Connector, IEEE488, Reverse, R/A, Female

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

203. CY1 6-00010-620 4.000 MHZ Crystal

204. D 101 3-00004-301 1N4148 Diode

205. D 102 3-00004-301 1N4148 Diode

206. D 103 3-00004-301 1N4148 Diode

207. D 104 3-00004-301 1N4148 Diode

208. D 105 3-00004-301 1N4148 Diode

209. D 106 3-00004-301 1N4148 Diode

210. D 201 3-00004-301 1N4148 Diode

211. D 202 3-00004-301 1N4148 Diode

212. D 203 3-00004-301 1N4148 Diode

213. D 204 3-00004-301 1N4148 Diode

214. D 301 3-00004-301 1N4148 Diode

215. D 302 3-00004-301 1N4148 Diode

216. D 303 3-00004-301 1N4148 Diode

217. D 401 3-00004-301 1N4148 Diode

218. D 402 3-00004-301 1N4148 Diode

219. D 403 3-00004-301 1N4148 Diode

220. D 404 3-00004-301 1N4148 Diode

221. D 501 3-00004-301 1N4148 Diode

222. D 502 3-00004-301 1N4148 Diode

223. D 701 3-00007-301 1N747A Diode

224. D 702 3-00203-301 1N5711 Diode

225. D 703 3-00203-301 1N5711 Diode

226. D 704 3-00004-301 1N4148 Diode

227. D 901 3-00003-301 1N4007 Diode

228. D 902 3-00003-301 1N4007 Diode

229. D 903 3-00003-301 1N4007 Diode

230. D 904 3-00003-301 1N4007 Diode

231. FU1 6-00004-611 1A 3AG Fuse

232. P 101 4-00006-440 20 Trim Pot, Single Turn, In-Line Leads

233. P 102 4-00012-441 20K Pot, Multi-Turn Trim, 3/8" Square Top Ad

234. P 103 4-00012-441 20K Pot, Multi-Turn Trim, 3/8" Square Top Ad

235. P 104 4-00013-441 50K Pot, Multi-Turn Trim, 3/8" Square Top Ad

236. P 105 4-00014-441 5K Pot, Multi-Turn Trim, 3/8" Square Top Ad

237. P 401 4-00011-441 10K Pot, Multi-Turn Trim, 3/8" Square Top Ad

238. P 402 4-00011-441 10K Pot, Multi-Turn Trim, 3/8" Square Top Ad

239. P 403 4-00011-441 10K Pot, Multi-Turn Trim, 3/8" Square Top Ad

240. P 404 4-00011-441 10K Pot, Multi-Turn Trim, 3/8" Square Top Ad

241. P 501 4-00002-440 100 Trim Pot, Single Turn, In-Line Leads

242. P 502 4-00002-440 100 Trim Pot, Single Turn, In-Line Leads

243. PC1 7-00036-701 SR500 Printed Circuit Board

244. Q 101 3-00016-323 2N6485 Transistor, TO-71 Package

245. Q 102 3-00016-323 2N6485 Transistor, TO-71 Package

246. Q 103 3-00031-325 MPSA18 Transistor, TO-92 Package

247. Q 201 3-00887-325 MPS2907A Transistor, TO-92 Package

248. Q 202 3-00026-325 2N5210 Transistor, TO-92 Package

249. Q 502 3-00026-325 2N5210 Transistor, TO-92 Package

250. Q 701 3-00026-325 2N5210 Transistor, TO-92 Package

251. Q 702 3-00026-325 2N5210 Transistor, TO-92 Package

252. Q 703 3-00026-325 2N5210 Transistor, TO-92 Package

253. R 101 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

254. R 102 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

255. R 103 4-00030-401 10 Resistor, Carbon Film, 1/4W, 5%

256. R 104 4-00031-401 100 Resistor, Carbon Film, 1/4W, 5%

257. R 105 4-00031-401 100 Resistor, Carbon Film, 1/4W, 5%

258. R 108 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

259. R 109 4-00199-407 6.81K Resistor, Metal Film, 1/8W, 1%, 50PPM

260. R 110 4-00199-407 6.81K Resistor, Metal Film, 1/8W, 1%, 50PPM

261. R 111 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

262. R 112 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

263 R 113 4-00145-407 110 Resistor, Metal Film, 1/8W, 1%, 50PPM

264. R 114 4-00145-407 110 Resistor, Metal Film, 1/8W, 1%, 50PPM

265. R 115 4-00047-401 2.2 Resistor, Carbon Film, 1/4W, 5%

266. R 116 4-00196-407 6.04K Resistor, Metal Film, 1/8W, 1%, 50PPM

267. R 117 4-00210-407 9.09K Resistor, Metal Film, 1/8W, 1%, 50PPM

268. R 118 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

269. R 119 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

270. R 120 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

271. R 121 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

272. R 122 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

273. R 126 4-00210-407 9.09K Resistor, Metal Film, 1/8W, 1%, 50PPM

274. R 127 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

275. R 128 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

276. R 130 4-00082-401 470K Resistor, Carbon Film, 1/4W, 5%

277. R 132 4-00082-401 470K Resistor, Carbon Film, 1/4W, 5%

278. R 133 4-00179-407 30.1K Resistor, Metal Film, 1/8W, 1%, 50PPM

279. R 134 4-00179-407 30.1K Resistor, Metal Film, 1/8W, 1%, 50PPM

280. R 135 4-00131-407 1.00M Resistor, Metal Film, 1/8W, 1%, 50PPM

281. R 138 4-00052-401 20 Resistor, Carbon Film, 1/4W, 5%

282. R 139 4-00052-401 20 Resistor, Carbon Film, 1/4W, 5%

283. R 140 4-00150-407 13.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

284. R 141 4-00174-407 280 Resistor, Metal Film, 1/8W, 1%, 50PPM

285. R 142 4-00168-407 22.6K Resistor, Metal Film, 1/8W, 1%, 50PPM

286. R 143 4-00150-407 13.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

287. R 144 4-00157-407 16.9K Resistor, Metal Film, 1/8W, 1%, 50PPM

288. R 145 4-00157-407 16.9K Resistor, Metal Film, 1/8W, 1%, 50PPM

289. R 146 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

290. R 147 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

291. R 148 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

292. R 149 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

293. R 150 4-00179-407 30.1K Resistor, Metal Film, 1/8W, 1%, 50PPM

294. R 151 4-00201-407 634 Resistor, Metal Film, 1/8W, 1%, 50PPM

295. R 152 4-00195-407 54.9K Resistor, Metal Film, 1/8W, 1%, 50PPM

296. R 153 4-00176-407 3.01K Resistor, Metal Film, 1/8W, 1%, 50PPM

297. R 154 4-00178-407 3.83K Resistor, Metal Film, 1/8W, 1%, 50PPM

298. R 155 4-00211-407 9.53K Resistor, Metal Film, 1/8W, 1%, 50PPM

299. R 156 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

300. R 157 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

301. R 158 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

302. R 159 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

303. R 160 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

304. R 161 4-00204-407 750 Resistor, Metal Film, 1/8W, 1%, 50PPM

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

305. R 162 4-00188-407 4.99K Resistor, Metal Film, 1/8W, 1%, 50PPM

306. R 163 4-00035-401 10M Resistor, Carbon Film, 1/4W, 5%

307. R 165 4-00215-407 909 Resistor, Metal Film, 1/8W, 1%, 50PPM

308. R 166 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

309. R 167 4-00215-407 909 Resistor, Metal Film, 1/8W, 1%, 50PPM

310. R 168 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

311. R 169 4-00134-407 1.24K Resistor, Metal Film, 1/8W, 1%, 50PPM

312. R 170 4-00144-407 107 Resistor, Metal Film, 1/8W, 1%, 50PPM

313. R 171 4-00182-407 33.2 Resistor, Metal Film, 1/8W, 1%, 50PPM

314. R 172 4-00035-401 10M Resistor, Carbon Film, 1/4W, 5%

315. R 173 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

316. R 174 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

317. R 175 4-00165-407 200 Resistor, Metal Film, 1/8W, 1%, 50PPM

318. R 176 4-00211-407 9.53K Resistor, Metal Film, 1/8W, 1%, 50PPM

319. R 177 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

320. R 178 4-00035-401 10M Resistor, Carbon Film, 1/4W, 5%

321. R 201 4-00135-407 1.50K Resistor, Metal Film, 1/8W, 1%, 50PPM

322. R 202 4-00194-407 5.11K Resistor, Metal Film, 1/8W, 1%, 50PPM

323. R 203 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

324. R 204 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

325. R 205 4-00153-407 15.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

326. R 206 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

327. R 207 4-00135-407 1.50K Resistor, Metal Film, 1/8W, 1%, 50PPM

328. R 208 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

329. R 209 4-00150-407 13.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

330. R 210 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

331. R 211 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

332. R 212 4-00135-407 1.50K Resistor, Metal Film, 1/8W, 1%, 50PPM

333. R 213 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

334. R 214 4-00150-407 13.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

335. R 215 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

336. R 216 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

337. R 217 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

338. R 218 4-00035-401 10M Resistor, Carbon Film, 1/4W, 5%

339. R 219 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

340. R 220 4-00177-407 3.48K Resistor, Metal Film, 1/8W, 1%, 50PPM

341. R 221 4-00039-401 120K Resistor, Carbon Film, 1/4W, 5%

342. R 222 4-00096-401 62K Resistor, Carbon Film, 1/4W, 5%

343. R 223 4-00039-401 120K Resistor, Carbon Film, 1/4W, 5%

344. R 224 4-00094-401 6.8K Resistor, Carbon Film, 1/4W, 5%

345. R 225 4-00063-401 3.0K Resistor, Carbon Film, 1/4W, 5%

346. R 226 4-00094-401 6.8K Resistor, Carbon Film, 1/4W, 5%

347. R 227 4-00063-401 3.0K Resistor, Carbon Film, 1/4W, 5%

348. R 228 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

349. R 229 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

350. R 301 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

351. R 302 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

352. R 303 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

353. R 304 4-00045-401 2.0K Resistor, Carbon Film, 1/4W, 5%

354. R 305 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

355. R 306 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

356. R 307 4-00040-401 13K Resistor, Carbon Film, 1/4W, 5%

357. R 308 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

358. R 309 4-00073-401 330K Resistor, Carbon Film, 1/4W, 5%

359. R 310 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

360. R 311 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

361. R 312 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

362. R 313 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

363. R 314 4-00069-401 300K Resistor, Carbon Film, 1/4W, 5%

364. R 315 4-00099-401 680K Resistor, Carbon Film, 1/4W, 5%

365. R 316 4-00099-401 680K Resistor, Carbon Film, 1/4W, 5%

366. R 317 4-00093-401 6.2K Resistor, Carbon Film, 1/4W, 5%

367. R 318 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

368. R 319 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

369. R 320 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

370. R 321 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

371. R 322 4-00170-407 249K Resistor, Metal Film, 1/8W, 1%, 50PPM

372. R 323 4-00199-407 6.81K Resistor, Metal Film, 1/8W, 1%, 50PPM

373. R 324 4-00199-407 6.81K Resistor, Metal Film, 1/8W, 1%, 50PPM

374. R 325 4-00163-407 2.80K Resistor, Metal Film, 1/8W, 1%, 50PPM

375. R 326 4-00150-407 13.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

376. R 327 4-00159-407 2.10K Resistor, Metal Film, 1/8W, 1%, 50PPM

377. R 328 4-00029-401 1.8K Resistor, Carbon Film, 1/4W, 5%

378. R 329 4-00088-401 51K Resistor, Carbon Film, 1/4W, 5%

379. R 330 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

380. R 332 4-00161-407 2.49K Resistor, Metal Film, 1/8W, 1%, 50PPM

381. R 333 4-00029-401 1.8K Resistor, Carbon Film, 1/4W, 5%

382. R 334 4-00197-407 6.49K Resistor, Metal Film, 1/8W, 1%, 50PPM

383. R 335 4-00088-401 51K Resistor, Carbon Film, 1/4W, 5%

384. R 336 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

385. R 337 4-00035-401 10M Resistor, Carbon Film, 1/4W, 5%

386. R 338 4-00030-401 10 Resistor, Carbon Film, 1/4W, 5%

387. R 339 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

388. R 340 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

389. R 341 4-00025-401 1.2M Resistor, Carbon Film, 1/4W, 5%

390. R 342 4-00073-401 330K Resistor, Carbon Film, 1/4W, 5%

391. R 343 4-00046-401 2.0M Resistor, Carbon Film, 1/4W, 5%

392. R 344 4-00069-401 300K Resistor, Carbon Film, 1/4W, 5%

393. R 345 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

394. R 346 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

395. R 347 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

396. R 348 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

397. R 349 4-00069-401 300K Resistor, Carbon Film, 1/4W, 5%

398. R 350 4-00093-401 6.2K Resistor, Carbon Film, 1/4W, 5%

399. R 351 4-00138-407 10.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

400. R 352 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

401. R 353 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

402. R 354 4-00203-407 75.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

403. R 355 4-00187-407 4.53K Resistor, Metal Film, 1/8W, 1%, 50PPM

404. R 356 4-00160-407 2.26K Resistor, Metal Film, 1/8W, 1%, 50PPM

405. R 357 4-00163-407 2.80K Resistor, Metal Film, 1/8W, 1%, 50PPM

406. R 358 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

407. R 359 4-00045-401 2.0K Resistor, Carbon Film, 1/4W, 5%

408. R 360 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

409. R 361 4-00084-401 5.1K Resistor, Carbon Film, 1/4W, 5%

410. R 362 4-00181-407 32.4K Resistor, Metal Film, 1/8W, 1%, 50PPM

411. R 363 4-00132-407 1.10K Resistor, Metal Film, 1/8W, 1%, 50PPM

412. R 364 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

413. R 365 4-00045-401 2.0K Resistor, Carbon Film, 1/4W, 5%

414. R 366 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

415. R 367 4-00151-407 130K Resistor, Metal Film, 1/8W, 1%, 50PPM

416. R 368 4-00156-407 16.2K Resistor, Metal Film, 1/8W, 1%, 50PPM

417. R 369 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

418. R 370 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

419. R 371 4-00030-401 10 Resistor, Carbon Film, 1/4W, 5%

420. R 372 4-00023-401 1.1M Resistor, Carbon Film, 1/4W, 5%

421. R 373 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

422. R 374 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

423. R 375 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

424. R 376 4-00033-404 100M Resistor, Carbon Comp, 1/4W, 5%

425. R 377 4-00187-407 4.53K Resistor, Metal Film, 1/8W, 1%, 50PPM

426. R 378 4-00045-401 2.0K Resistor, Carbon Film, 1/4W, 5%

427. R 401 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

428. R 402 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

429. R 403 4-00085-401 5.1M Resistor, Carbon Film, 1/4W, 5%

430. R 404 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

431. R 405 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

432. R 406 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

433. R 407 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

434. R 408 4-00131-407 1.00M Resistor, Metal Film, 1/8W, 1%, 50PPM

435. R 409 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

436. R 410 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

437. R 411 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

438. R 412 4-00217-408 1.000K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

439. R 413 4-00203-407 75.0K Resistor, Metal Film, 1/8W, 1%, 50PPM

440. R 414 4-00080-401 47 Resistor, Carbon Film, 1/4W, 5%

441. R 415 4-00142-407 100K Resistor, Metal Film, 1/8W, 1%, 50PPM

442. R 417 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

443. R 418 4-00132-407 1.10K Resistor, Metal Film, 1/8W, 1%, 50PPM

444. R 419 4-00179-407 30.1K Resistor, Metal Film, 1/8W, 1%, 50PPM

445. R 420 4-00183-407 348K Resistor, Metal Film, 1/8W, 1%, 50PPM

446. R 421 4-00155-407 150K Resistor, Metal Film, 1/8W, 1%, 50PPM

447. R 422 4-00184-407 37.4K Resistor, Metal Film, 1/8W, 1%, 50PPM

448. R 423 4-00212-407 9.76K Resistor, Metal Film, 1/8W, 1%, 50PPM

449. R 424 4-00161-407 2.49K Resistor, Metal Film, 1/8W, 1%, 50PPM

450. R 425 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

451. R 426 4-00045-401 2.0K Resistor, Carbon Film, 1/4W, 5%

452. R 427 4-00131-407 1.00M Resistor, Metal Film, 1/8W, 1%, 50PPM

453. R 428 4-00131-407 1.00M Resistor, Metal Film, 1/8W, 1%, 50PPM

454. R 429 4-00146-407 110K Resistor, Metal Film, 1/8W, 1%, 50PPM

455. R 430 4-00140-407 10.2K Resistor, Metal Film, 1/8W, 1%, 50PPM

456. R 431 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

457. R 432 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

458. R 433 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

459. R 501 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

460. R 502 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

461. R 503 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

462. R 504 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

463. R 505 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

464. R 506 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

465. R 507 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

466. R 508 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

467. R 509 4-00218-408 10.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

468. R 510 4-00219-408 20.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

469. R 511 4-00218-408 10.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

470. R 512 4-00219-408 20.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

471. R 513 4-00166-407 200K Resistor, Metal Film, 1/8W, 1%, 50PPM

472. R 514 4-00207-407 806K Resistor, Metal Film, 1/8W, 1%, 50PPM

473. R 515 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

474. R 516 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

475. R 518 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

476. R 519 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

477. R 520 4-00086-401 51 Resistor, Carbon Film, 1/4W, 5%

478. R 521 4-00086-401 51 Resistor, Carbon Film, 1/4W, 5%

479. R 522 4-00218-408 10.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

480. R 523 4-00218-408 10.00K Resistor, Metal Film, 1/8W, 0.1%, 25ppm

481. R 524 4-00078-401 39K Resistor, Carbon Film, 1/4W, 5%

482. R 525 4-00059-401 22K Resistor, Carbon Film, 1/4W, 5%

483. R 526 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

484. R 527 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

485. R 528 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

486. R 529 4-00057-401 220 Resistor, Carbon Film, 1/4W, 5%

487. R 530 4-00210-407 9.09K Resistor, Metal Film, 1/8W, 1%, 50PPM

488. R 531 4-00130-407 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM

489. R 532 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

490. R 533 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

491. R 534 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

492. R 535 4-00057-401 220 Resistor, Carbon Film, 1/4W, 5%

493. R 536 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

494. R 537 4-00057-401 220 Resistor, Carbon Film, 1/4W, 5%

495. R 538 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

496. R 539 4-00057-401 220 Resistor, Carbon Film, 1/4W, 5%

497. R 540 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

498. R 541 4-00057-401 220 Resistor, Carbon Film, 1/4W, 5%

499. R 542 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

500. R 543 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

501. R 544 4-00042-401 15K Resistor, Carbon Film, 1/4W, 5%

502. R 545 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

503. R 546 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

504. R 547 4-00042-401 15K Resistor, Carbon Film, 1/4W, 5%

505. R 548 4-00054-401 200K Resistor, Carbon Film, 1/4W, 5%

506. R 549 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

507. R 701 4-00031-401 100 Resistor, Carbon Film, 1/4W, 5%

508. R 702 4-00079-401 4.7K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

509. R 703 4-00027-401 1.5K Resistor, Carbon Film, 1/4W, 5%

510. R 705 4-00021-401 1.0K Resistor, Carbon Film, 1/4W, 5%

511. R 706 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

512. R 707 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

513. R 708 4-00069-401 300K Resistor, Carbon Film, 1/4W, 5%

514. R 709 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

515. R 710 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

516. R 711 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

517. R 712 4-00032-401 100K Resistor, Carbon Film, 1/4W, 5%

518. R 801 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

519. R 802 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

520. R 803 4-00065-401 3.3K Resistor, Carbon Film, 1/4W, 5%

521. R 901 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

522. R 902 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

523. R 903 4-00060-401 240 Resistor, Carbon Film, 1/4W, 5%

524. R 904 4-00024-401 1.2K Resistor, Carbon Film, 1/4W, 5%

525. R 905 4-00024-401 1.2K Resistor, Carbon Film, 1/4W, 5%

526. R 906 4-00060-401 240 Resistor, Carbon Film, 1/4W, 5%

527. R 907 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

528. R 908 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

529. R 909 4-00053-401 200 Resistor, Carbon Film, 1/4W, 5%

530. R 910 4-00063-401 3.0K Resistor, Carbon Film, 1/4W, 5%

531. R 911 4-00063-401 3.0K Resistor, Carbon Film, 1/4W, 5%

532. R 912 4-00053-401 200 Resistor, Carbon Film, 1/4W, 5%

533. R 913 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

534. R 914 4-00107-402 10 Resistor, Carbon Comp, 1/2W, 5%

535. RN401 4-00220-420 10KX8 Resistor Network, DIP, 1/4W,2%,8 Ind

536. RN801 4-00225-425 100KX9 Resistor Network SIP 1/4W 2% (Common)

537. RN802 4-00225-425 100KX9 Resistor Network SIP 1/4W 2% (Common)

538. SO702 1-00026-150 28 PIN 600 MIL Socket, THRU-HOLE

539. SW1 2-00014-207 SPSTX8 Switch, DIP

540. SW2 2-00014-207 SPSTX8 Switch, DIP

541. SW601 2-00017-216 4PDT Switch, Rocker, PCB Mount (LHS of 510)

542. SW602 2-00004-213 DPDT Switch, Rocker, PCB Mount (RHS of 510)

543. T 1 6-00007-610 SR510/530 Transformer

544. U 101 8-00085-860 SR513 ASSY SRS sub assemblies

545. U 102 8-00085-860 SR513 ASSY SRS sub assemblies

546. U 103 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

547. U 104 3-00118-325 78L15 Transistor, TO-92 Package

548. U 105 3-00124-325 79L15 Transistor, TO-92 Package

549. U 106 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

550. U 107 3-00130-340 5532A Integrated Circuit (Thru-hole Pkg)

551. U 108 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

552. U 109 3-00088-340 LF353 Integrated Circuit (Thru-hole Pkg)

553. U 110 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

554. U 111 3-00089-340 LF357 Integrated Circuit (Thru-hole Pkg)

555. U 112 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

556. U 113 3-00089-340 LF357 Integrated Circuit (Thru-hole Pkg)

557. U 114 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

558. U 115 3-00089-340 LF357 Integrated Circuit (Thru-hole Pkg)

559. U 117 3-00088-340 LF353 Integrated Circuit (Thru-hole Pkg)

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

560. U 118 3-00130-340 5532A Integrated Circuit (Thru-hole Pkg)

561. U 201 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

562. U 202 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

563. U 203 3-00073-340 CD4052 Integrated Circuit (Thru-hole Pkg)

564. U 204 3-00073-340 CD4052 Integrated Circuit (Thru-hole Pkg)

565. U 205 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

566. U 206 3-00038-340 74HC139 Integrated Circuit (Thru-hole Pkg)

567. U 207 3-00038-340 74HC139 Integrated Circuit (Thru-hole Pkg)

568. U 208 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

569. U 301 3-00088-340 LF353 Integrated Circuit (Thru-hole Pkg)

570. U 303 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

571. U 304 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

572. U 305 3-00075-340 CD4538 Integrated Circuit (Thru-hole Pkg)

573. U 306 3-00072-340 CD4046 Integrated Circuit (Thru-hole Pkg)

574. U 307 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

575. U 308 3-00066-340 CA3140E Integrated Circuit (Thru-hole Pkg)

576. U 309 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

577. U 310 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

578. U 311 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

579. U 312 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

580. U 313 3-00049-340 74HC74 Integrated Circuit (Thru-hole Pkg)

581. U 314 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

582. U 315 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

583. U 316 3-00072-340 CD4046 Integrated Circuit (Thru-hole Pkg)

584. U 317 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

585. U 318 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

586. U 319 3-00066-340 CA3140E Integrated Circuit (Thru-hole Pkg)

587. U 320 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

588. U 321 3-00066-340 CA3140E Integrated Circuit (Thru-hole Pkg)

589. U 322 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

590. U 323 3-00093-340 LM13600 Integrated Circuit (Thru-hole Pkg)

591. U 324 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

592. U 325 3-00091-340 LF412 Integrated Circuit (Thru-hole Pkg)

593. U 326 3-00068-340 CD4018 Integrated Circuit (Thru-hole Pkg)

594. U 327 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

595. U 328 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

596. U 329 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

597. U 401 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

598. U 402 3-00091-340 LF412 Integrated Circuit (Thru-hole Pkg)

599. U 403 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg)

600. U 404 3-00106-340 LT1007 Integrated Circuit (Thru-hole Pkg)

601. U 405 3-00074-340 CD4066 Integrated Circuit (Thru-hole Pkg)

602. U 406 3-00057-340 AD534 Integrated Circuit (Thru-hole Pkg)

603. U 407 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg)

604. U 408 3-00106-340 LT1007 Integrated Circuit (Thru-hole Pkg)

605. U 409 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg)

606. U 410 3-00084-340 ICL7650 Integrated Circuit (Thru-hole Pkg)

607. U 411 3-00126-335 51A05 Relay

608. U 412 3-00126-335 51A05 Relay

609. U 413 3-00126-335 51A05 Relay

610. U 414 3-00126-335 51A05 Relay

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

611. U 415 3-00126-335 51A05 Relay

612. U 416 3-00084-340 ICL7650 Integrated Circuit (Thru-hole Pkg)

613. U 417 3-00126-335 51A05 Relay

614. U 418 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

615. U 419 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg)

616. U 420 3-00064-340 CA3081 Integrated Circuit (Thru-hole Pkg)

617. U 421 3-00035-340 74C74 Integrated Circuit (Thru-hole Pkg)

618. U 501 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

619. U 502 3-00058-340 AD7524 Integrated Circuit (Thru-hole Pkg)

620. U 503 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

621. U 504 3-00077-340 DG528 Integrated Circuit (Thru-hole Pkg)

622. U 505 3-00059-340 AD7542JN Integrated Circuit (Thru-hole Pkg)

623. U 506 3-00058-340 AD7524 Integrated Circuit (Thru-hole Pkg)

624. U 507 3-00077-340 DG528 Integrated Circuit (Thru-hole Pkg)

625. U 508 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

626. U 509 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

627. U 510 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

628. U 511 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

629. U 512 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

630. U 513 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

631. U 514 3-00094-340 LM311 Integrated Circuit (Thru-hole Pkg)

632. U 515 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

633. U 516 3-00076-340 DG211 Integrated Circuit (Thru-hole Pkg)

634. U 517 3-00092-340 LH0071 Integrated Circuit (Thru-hole Pkg)

635. U 701 3-00132-340 Z80A-CPU Integrated Circuit (Thru-hole Pkg)

636. U 703 3-00081-341 2KX8-100 STATIC RAM, I.C.

637. U 704 3-00491-340 UPD71054C Integrated Circuit (Thru-hole Pkg)

638. U 705 3-00037-340 74HC138 Integrated Circuit (Thru-hole Pkg)

639. U 706 3-00037-340 74HC138 Integrated Circuit (Thru-hole Pkg)

640. U 707 3-00037-340 74HC138 Integrated Circuit (Thru-hole Pkg)

641. U 708 3-00040-340 74HC157 Integrated Circuit (Thru-hole Pkg)

642. U 709 3-00049-340 74HC74 Integrated Circuit (Thru-hole Pkg)

643. U 710 3-00045-340 74HC32 Integrated Circuit (Thru-hole Pkg)

644. U 711 3-00051-340 74HCU04 Integrated Circuit (Thru-hole Pkg)

645. U 712 3-00047-340 74HC4040 Integrated Circuit (Thru-hole Pkg)

646. U 713 3-00049-340 74HC74 Integrated Circuit (Thru-hole Pkg)

647. U 714 3-00042-340 74HC175 Integrated Circuit (Thru-hole Pkg)

648. U 715 3-00042-340 74HC175 Integrated Circuit (Thru-hole Pkg)

649. U 716 3-00044-340 74HC244 Integrated Circuit (Thru-hole Pkg)

650. U 717 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

651. U 718 3-00039-340 74HC14 Integrated Circuit (Thru-hole Pkg)

652. U 719 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

653. U 720 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

654. U 721 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

655. U 722 3-00045-340 74HC32 Integrated Circuit (Thru-hole Pkg)

656. U 801 3-00493-340 UPD71051C Integrated Circuit (Thru-hole Pkg)

657. U 802 3-00111-340 MC68488 Integrated Circuit (Thru-hole Pkg)

658. U 803 3-00044-340 74HC244 Integrated Circuit (Thru-hole Pkg)

659. U 804 3-00044-340 74HC244 Integrated Circuit (Thru-hole Pkg)

660. U 805 3-00049-340 74HC74 Integrated Circuit (Thru-hole Pkg)

661. U 806 3-00109-340 MC1488 Integrated Circuit (Thru-hole Pkg)

SR510 PARTS LIST

No REF. SRS part# VALUE DESCRIPTION

662. U 807 3-00110-340 MC1489 Integrated Circuit (Thru-hole Pkg)

663. U 808 3-00078-340 DS75160A Integrated Circuit (Thru-hole Pkg)

664. U 809 3-00117-325 78L12 Transistor, TO-92 Package

665. U 810 3-00123-325 79L12 Transistor, TO-92 Package

666. U 811 3-00079-340 DS75161A Integrated Circuit (Thru-hole Pkg)

667. U 901 3-00095-331 LM317K Voltage Regulator, TO-3 Metal Can

668. U 902 3-00099-331 LM337K Voltage Regulator, TO-3 Metal Can

669. U 903 3-00114-329 7815 Voltage Reg., TO-220 (TAB) Package

670. U 904 3-00114-329 7815 Voltage Reg., TO-220 (TAB) Package

671. U 905 3-00114-329 7815 Voltage Reg., TO-220 (TAB) Package

672. U 906 3-00120-329 7915 Voltage Reg., TO-220 (TAB) Package

673. U 907 3-00120-329 7915 Voltage Reg., TO-220 (TAB) Package

674. U 908 3-00120-329 7915 Voltage Reg., TO-220 (TAB) Package

675. U 909 3-00113-340 7805CK Integrated Circuit (Thru-hole Pkg)

676. U 910 3-00116-325 78L05 Transistor, TO-92 Package

677. U 911 3-00096-340 LM317L Integrated Circuit (Thru-hole Pkg)

678. U 912 3-00100-340 LM337L Integrated Circuit (Thru-hole Pkg)

679. Z 0 0-00004-007 SR510 Heat Sinks

680. Z 0 0-00014-002 6J4 Power_Entry Hardware

681. Z 0 0-00016-000 TIE ANCHOR Hardware, Misc.

682. Z 0 0-00017-002 TRANSCOVER Power_Entry Hardware

683. Z 0 0-00019-003 MICA Insulators

684. Z 0 0-00025-005 3/8" Lugs

685. Z 0 0-00043-011 4-40 KEP Nut, Kep

686. Z 0 0-00048-011 6-32 KEP Nut, Kep

687. Z 0 0-00064-027 6-20X5/8P Screw, Sheet Metal

688. Z 0 0-00079-031 4-40X3/16 M/F Standoff

689. Z 0 0-00084-032 36154 Termination

690. Z 0 0-00089-033 4" Tie

691. Z 0 0-00095-040 #4 FLAT Washer, Flat

692. Z 0 0-00096-041 #4 SPLIT Washer, Split

693. Z 0 0-00114-050 10-1/8"#18 Wire #18 UL1007 Stripped 3/8x3/8 No Tin

694. Z 0 0-00117-053 12" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

695. Z 0 0-00130-050 5-5/8" #18 Wire #18 UL1007 Stripped 3/8x3/8 No Tin

696. Z 0 0-00132-053 6-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

697. Z 0 0-00135-050 7-5/8" #18 Wire #18 UL1007 Stripped 3/8x3/8 No Tin

698. Z 0 0-00136-053 8-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

699. Z 0 0-00153-057 GROMMET2 Grommet

700. Z 0 0-00185-021 6-32X3/8PP Screw, Panhead Phillips

701. Z 0 0-00187-021 4-40X1/4PP Screw, Panhead Phillips

702. Z 0 0-00207-003 TO-5 Insulators

703. Z 0 0-00222-021 6-32X1/4PP Screw, Panhead Phillips

704. Z 0 0-00225-052 17" #22 BLACK Wire #22 UL1007

705. Z 0 0-00226-052 17" #22 WHITE Wire #22 UL1007

706. Z 0 0-00227-052 17" #22 RED Wire #22 UL1007

707. Z 0 0-00228-052 17" #22 GREEN Wire #22 UL1007

708. Z 0 0-00231-043 #4 SHOULDER Washer, nylon

709. Z 0 0-00233-000 HANDLE1 Hardware, Misc.

710. Z 0 0-00241-021 4-40X3/16PP Screw, Panhead Phillips

711. Z 0 0-00249-021 6-32X1-1/2PP Screw, Panhead Phillips

712. Z 0 0-00256-043 #6 SHOULDER Washer, nylon

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

713. Z 0 0-00371-026 4-40X3/16PF Screw, Black, All Types

714. Z 0 0-00500-000 554808-1 Hardware, Misc.

715. Z 0 0-00521-048 3" #18 Wire, #18 UL1015 Strip 3/8 x 3/8 No Tin

716. Z 0 0-00526-048 10-1/2" #18 Wire, #18 UL1015 Strip 3/8 x 3/8 No Tin

717. Z 0 0-00893-026 8-32X3/8PF Screw, Black, All Types

718. Z 0 1-00003-120 BNC Connector, BNC

719. Z 0 1-00010-130 20 PIN ELH Connector, Male

720. Z 0 1-00029-150 TO-3 Socket, THRU-HOLE

721. Z 0 1-00053-172 USA Line Cord

722. Z 0 7-00197-720 SR510-20 Fabricated Part

723. Z 0 7-00201-720 SR500-32 Fabricated Part

724. Z 0 7-00202-720 SR500-33 Fabricated Part

725. Z 0 7-00205-720 SR510-26 Fabricated Part

726. Z 0 9-00188-917 SR510/530 SER Product Labels

727. Z 0 9-00215-907 1/16" BLACK Shrink Tubing

728. Z 0 9-00216-907 1/8" BLACK Shrink Tubing

729. Z 0 9-00217-907 3/16" BLACK Shrink Tubing

Internal Oscillator PCB Parts List

NO REF. SRS part# VALUE DESCRIPTION

1. C 1 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20%, Z5U

2. C 2 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20%, Z5U

3. C 3 5-00102-517 4.7U Capacitor, Tantalum, 35V, 20%, Rad

4. C 4 5-00054-512 .047U Cap, Stacked Metal Film 50V 5% -40/+85c

5. C 5 5-00087-516 390P Capacitor, Silver Mica, 500V, 5%, DM15

6. C 6 5-00102-517 4.7U Capacitor, Tantalum, 35V, 20%, Rad

7. C 7 5-00014-501 390P Capacitor, Ceramic Disc, 50V, 10%, SL

8. C 8 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

9. C 9 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

10. C 10 5-00034-526 100U Capacitor, Electrolytic, 35V, 20%, Rad

11. C 11 5-00100-517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

12. P 1 4-00016-445 10K Pot, Multi-Turn, Side Adjust

13. P 2 4-00003-440 100K Trim Pot, Single Turn, In-Line Leads

14. P 3 4-00016-445 10K Pot, Multi-Turn, Side Adjust

15. PC1 7-00037-701 SR501 Printed Circuit Board

16. R 1 4-00079-401 4.7K Resistor, Carbon Film, 1/4W, 5%

17. R 2 4-00083-401 47K Resistor, Carbon Film, 1/4W, 5%

18. R 3 4-00202-407 698 Resistor, Metal Film, 1/8W, 1%, 50PPM

19. R 4 4-00189-407 41.2K Resistor, Metal Film, 1/8W, 1%, 50PPM

20. R 5 4-00186-407 4.22K Resistor, Metal Film, 1/8W, 1%, 50PPM

21. R 6 4-00190-407 42.2K Resistor, Metal Film, 1/8W, 1%, 50PPM

22. R 7 4-00186-407 4.22K Resistor, Metal Film, 1/8W, 1%, 50PPM

23. R 8 4-00202-407 698 Resistor, Metal Film, 1/8W, 1%, 50PPM

24. R 9 4-00078-401 39K Resistor, Carbon Film, 1/4W, 5%

25. R 10 4-00186-407 4.22K Resistor, Metal Film, 1/8W, 1%, 50PPM

26. R 11 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

27. R 12 4-00042-401 15K Resistor, Carbon Film, 1/4W, 5%

28. R 13 4-00070-401 30K Resistor, Carbon Film, 1/4W, 5%

29. R 14 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

30. R 15 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

31. R 16 4-00079-401 4.7K Resistor, Carbon Film, 1/4W, 5%

32. R 17 4-00104-401 82K Resistor, Carbon Film, 1/4W, 5%

33. R 18 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

34. R 19 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

35. R 20 4-00188-407 4.99K Resistor, Metal Film, 1/8W, 1%, 50PPM

36. R 21 4-00188-407 4.99K Resistor, Metal Film, 1/8W, 1%, 50PPM

37. R 22 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

38. R 23 4-00022-401 1.0M Resistor, Carbon Film, 1/4W, 5%

39. R 24 4-00031-401 100 Resistor, Carbon Film, 1/4W, 5%

40. R 25 4-00031-401 100 Resistor, Carbon Film, 1/4W, 5%

41. SW1 2-00013-215 DPDT Switch, Toggle Right Angle PCB Mount

42. SW2 2-00013-215 DPDT Switch, Toggle Right Angle PCB Mount

43. U 1 3-00087-340 LF347 Integrated Circuit (Thru-hole Pkg)

44. U 2 3-00085-340 ICL8038 Integrated Circuit (Thru-hole Pkg)

45. U 3 3-00118-325 78L15 Transistor, TO-92 Package

46. U 4 3-00124-325 79L15 Transistor, TO-92 Package

47. Z 0 0-00100-040 1/4X1/16 Washer, Flat

48. Z 0 0-00122-053 2-1/4" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

49. Z 0 0-00136-053 8-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

Miscellaneous Parts List

NO REF. SRS part# VALUE DESCRIPTION

1. Z0 7-00204-720 SR500-35 Fabricated Part

2. U 702 3-00161-342 27128-150 EPROM/PROM, I.C.

3. Z 0 0-00045-013 4-40 MINI Nut, Mini

4. Z 0 0-00078-031 4-40X1 M/F Standoff

5. Z 0 0-00167-023 6-32X1/2RP Screw, Roundhead Phillips

6. Z 0 0-00179-000 RIGHT FOOT Hardware, Misc.

7. Z 0 0-00180-000 LEFT FOOT Hardware, Misc.

8. Z 0 0-00185-021 6-32X3/8PP Screw, Panhead Phillips

9. Z 0 0-00187-021 4-40X1/4PP Screw, Panhead Phillips

10. Z 0 0-00204-000 REAR FOOT Hardware, Misc.

11. Z 0 0-00209-021 4-40X3/8PP Screw, Panhead Phillips

12. Z 0 0-00247-026 6-32X1/4 TRUSSP Screw, Black, All Types

13. Z 0 0-00248-026 10-32X3/8TRUSSP Screw, Black, All Types

14. Z 0 0-00371-026 4-40X3/16PF Screw, Black, All Types

15. Z 0 6-00054-611 .375A 3AG Fuse

16. Z 0 7-00147-720 BAIL Fabricated Part

17. Z 0 7-00198-720 SR510-23 Fabricated Part

18. Z 0 7-00199-720 SR510-24 Fabricated Part

19. Z 0 7-00200-720 SR510-25 Fabricated Part

20. Z 0 7-00203-720 SR500-34 Fabricated Part

SR510 PARTS LIST

Front Panel Parts List

NO REF. SRS part# VALUE DESCRIPTION

1. C 601 5-00019-501 68P Capacitor, Ceramic Disc, 50V, 10%, SL

2. C 602 5-00019-501 68P Capacitor, Ceramic Disc, 50V, 10%, SL

3. C 603 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

4. C 604 5-00052-512 .01U Cap, Stacked Metal Film 50V 5% -40/+85c

5. C 605 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

6. C 606 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

7. C 607 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20%, Z5U

8. D 601 3-00004-301 1N4148 Diode

9. D 602 3-00004-301 1N4148 Diode

10. D 603 3-00004-301 1N4148 Diode

11. D 604 3-00004-301 1N4148 Diode

12. DS601 3-00012-306 GREEN LED, Rectangular

13. DS602 3-00012-306 GREEN LED, Rectangular

14. DS603 3-00012-306 GREEN LED, Rectangular

15. DS604 3-00012-306 GREEN LED, Rectangular

16. DS605 3-00012-306 GREEN LED, Rectangular

17. DS606 3-00012-306 GREEN LED, Rectangular

18. DS607 3-00012-306 GREEN LED, Rectangular

19. DS608 3-00012-306 GREEN LED, Rectangular

20. DS609 3-00012-306 GREEN LED, Rectangular

21. DS610 3-00012-306 GREEN LED, Rectangular

22. DS611 3-00012-306 GREEN LED, Rectangular

23. DS612 3-00012-306 GREEN LED, Rectangular

24. DS613 3-00012-306 GREEN LED, Rectangular

25. DS614 3-00012-306 GREEN LED, Rectangular

26. DS615 3-00012-306 GREEN LED, Rectangular

27. DS616 3-00012-306 GREEN LED, Rectangular

28. DS617 3-00012-306 GREEN LED, Rectangular

29. DS618 3-00012-306 GREEN LED, Rectangular

30. DS619 3-00012-306 GREEN LED, Rectangular

31. DS620 3-00012-306 GREEN LED, Rectangular

32. DS621 3-00012-306 GREEN LED, Rectangular

33. DS622 3-00012-306 GREEN LED, Rectangular

34. DS623 3-00012-306 GREEN LED, Rectangular

35. DS624 3-00012-306 GREEN LED, Rectangular

36. DS625 3-00012-306 GREEN LED, Rectangular

37. DS626 3-00012-306 GREEN LED, Rectangular

38. DS627 3-00012-306 GREEN LED, Rectangular

39. DS628 3-00012-306 GREEN LED, Rectangular

40. DS629 3-00012-306 GREEN LED, Rectangular

41. DS630 3-00012-306 GREEN LED, Rectangular

42. DS631 3-00012-306 GREEN LED, Rectangular

43. DS632 3-00012-306 GREEN LED, Rectangular

44. DS633 3-00012-306 GREEN LED, Rectangular

45. DS634 3-00012-306 GREEN LED, Rectangular

46. DS635 3-00012-306 GREEN LED, Rectangular

47. DS636 3-00012-306 GREEN LED, Rectangular

48. DS637 3-00012-306 GREEN LED, Rectangular

49. DS638 3-00013-306 RED LED, Rectangular

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

50. DS639 3-00013-306 RED LED, Rectangular

51. DS640 3-00013-306 RED LED, Rectangular

52. DS641 3-00012-306 GREEN LED, Rectangular

53. DS642 3-00012-306 GREEN LED, Rectangular

54. DS643 3-00012-306 GREEN LED, Rectangular

55. DS644 3-00012-306 GREEN LED, Rectangular

56. DS645 3-00012-306 GREEN LED, Rectangular

57. DS646 3-00012-306 GREEN LED, Rectangular

58. DS647 3-00012-306 GREEN LED, Rectangular

59. DS648 3-00012-306 GREEN LED, Rectangular

60. DS649 3-00012-306 GREEN LED, Rectangular

61. DS650 3-00012-306 GREEN LED, Rectangular

62. DS651 3-00012-306 GREEN LED, Rectangular

63. DS652 3-00012-306 GREEN LED, Rectangular

64. DS653 3-00012-306 GREEN LED, Rectangular

65. DS654 3-00012-306 GREEN LED, Rectangular

66. DS655 3-00012-306 GREEN LED, Rectangular

67. DS656 3-00012-306 GREEN LED, Rectangular

68. DS657 3-00012-306 GREEN LED, Rectangular

69. DS658 3-00012-306 GREEN LED, Rectangular

70. DS659 3-00012-306 GREEN LED, Rectangular

71. DS660 3-00012-306 GREEN LED, Rectangular

72. DS661 3-00012-306 GREEN LED, Rectangular

73. DS662 3-00012-306 GREEN LED, Rectangular

74. LD1 8-00001-820 FE0206 LCD Display

75. LD2 8-00001-820 FE0206 LCD Display

76. M 1 8-00002-801 #DIV/0! Analog Meter

77. PB601 2-00001-201 D6-01-01 Switch, Momentary Push Button

78. PB602 2-00001-201 D6-01-01 Switch, Momentary Push Button

79. PB603 2-00001-201 D6-01-01 Switch, Momentary Push Button

80. PB604 2-00001-201 D6-01-01 Switch, Momentary Push Button

81. PB605 2-00001-201 D6-01-01 Switch, Momentary Push Button

82. PB606 2-00001-201 D6-01-01 Switch, Momentary Push Button

83. PB607 2-00001-201 D6-01-01 Switch, Momentary Push Button

84. PB608 2-00001-201 D6-01-01 Switch, Momentary Push Button

85. PB609 2-00001-201 D6-01-01 Switch, Momentary Push Button

86. PB610 2-00001-201 D6-01-01 Switch, Momentary Push Button

87. PB611 2-00001-201 D6-01-01 Switch, Momentary Push Button

88. PB612 2-00001-201 D6-01-01 Switch, Momentary Push Button

89. PB613 2-00001-201 D6-01-01 Switch, Momentary Push Button

90. PB614 2-00001-201 D6-01-01 Switch, Momentary Push Button

91. PB615 2-00001-201 D6-01-01 Switch, Momentary Push Button

92. PB616 2-00001-201 D6-01-01 Switch, Momentary Push Button

93. PB617 2-00001-201 D6-01-01 Switch, Momentary Push Button

94. PB618 2-00001-201 D6-01-01 Switch, Momentary Push Button

95. PB619 2-00001-201 D6-01-01 Switch, Momentary Push Button

96. PB620 2-00001-201 D6-01-01 Switch, Momentary Push Button

97. PB621 2-00001-201 D6-01-01 Switch, Momentary Push Button

98. PB622 2-00001-201 D6-01-01 Switch, Momentary Push Button

99. PB623 2-00001-201 D6-01-01 Switch, Momentary Push Button

100. PB624 2-00001-201 D6-01-01 Switch, Momentary Push Button

SR510 PARTS LIST

NO REF. SRS part# VALUE DESCRIPTION

101. PB625 2-00001-201 D6-01-01 Switch, Momentary Push Button

102. PC1 7-00038-701 SR511 Printed Circuit Board

103. R 601 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

104. R 602 4-00034-401 10K Resistor, Carbon Film, 1/4W, 5%

105. RN601 4-00223-425 22KX7 Resistor Network SIP 1/4W 2% (Common)

106. RN602 4-00226-425 150X9 Resistor Network SIP 1/4W 2% (Common)

107. RN603 4-00226-425 150X9 Resistor Network SIP 1/4W 2% (Common)

108. RN604 4-00221-425 150X5 Resistor Network SIP 1/4W 2% (Common)

109. U 601 3-00086-340 ICM7211AM Integrated Circuit (Thru-hole Pkg)

110. U 602 3-00086-340 ICM7211AM Integrated Circuit (Thru-hole Pkg)

111. U 603 3-00044-340 74HC244 Integrated Circuit (Thru-hole Pkg)

112. U 604 3-00046-340 74HC374 Integrated Circuit (Thru-hole Pkg)

113. U 605 3-00071-340 CD4030 Integrated Circuit (Thru-hole Pkg)

114. U 606 3-00071-340 CD4030 Integrated Circuit (Thru-hole Pkg)

115. U 607 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

116. U 608 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

117. U 609 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

118. U 610 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

119. U 611 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

120. U 612 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

121. U 613 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

122. U 614 3-00053-340 74LS164 Integrated Circuit (Thru-hole Pkg)

123. Z 0 0-00042-010 4-40 HEX Nut, Hex

124. Z 0 0-00077-030 3/16"X5/16"NYLN Spacer

125. Z 0 0-00102-042 #10 LOCK Washer, lock

126. Z 0 0-00104-043 #4 NYLON Washer, nylon

127. Z 0 0-00106-044 CLEAR Window

128. Z 0 0-00111-053 1-3/4"#24B Wire #24 UL1007 Strip 1/4x1/4 Tin

129. Z 0 0-00112-053 1-3/4"#24R Wire #24 UL1007 Strip 1/4x1/4 Tin

130. Z 0 0-00117-053 12" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

131. Z 0 0-00128-053 4" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

132. Z 0 0-00129-053 5" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

133. Z 0 0-00132-053 6-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

134. Z 0 0-00139-054 9" #26 X20 Wire #26 UL1061

135. Z 0 0-00203-032 323914 Termination

136. Z 0 1-00011-130 20 PIN IDP Connector, Male

137. Z 0 1-00073-120 INSL Connector, BNC

138. Z 0 1-00145-131 20 PIN DIF POL Connector, Female

139. Z 0 7-00294-710 SR510-27 Front Panel

140. Z 0 7-00308-709 SR510 Lexan Overlay

141. Z 0 9-00554-913 INDIRECT, MFG MISC. EXPENSE ITEMS - QUICK FIX!

142. Z 0 9-00815-924 DBL-SIDED 1/2" Tape, All types

SR510 SR510m

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