Ritron RIT13-442 Handheld FM Transceiver User Manual 442 man

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Date Submitted	2001-05-15 00:00:00
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TYPE OF EXHIBIT:
INSTRUCTION MANUALS
FCC PART:
2.1033 (c)(3)
MANUFACTURER:
RITRON, INC.
505 West Carmel Drive
Carmel, IN 46032
MODEL:
SST-442
TYPE OF UNIT:
UHF-FM Handheld Transceiver
FCC ID:
AIERIT13-442
DATE:
May 11, 2001
Included in this exhibit is a draft of the Maintenance and Operating Manual for RITRON Model Patriot
SST-442 UHF-FM Handheld Transceiver.
Specifically, this manual includes a technical description of the SST-442 sufficient to establish compliance
with the technical standards of the applicable rule part(s).
This includes, but is not limited to, the following items required under FCC Part 2.1033 (c):
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
FCC Identifier.
A copy of the installation and operating instructions.
Type of emission.
Frequency range.
Range of operating power, and means to provide variation in operating power.
Maximum power rating.
DC voltage chart.
Tune-up procedure.
A description of all frequency determining and stabilization circuits. A description of the circuits
used to suppress spurious radiation, limiting modulation, and limiting power.
(12) Drawing with labels for controls and complete circuit diagrams.
Signed:
Michael A. Pickard - Project Engineer
TWO-WAY RADIO BY RITRON
RITRON MODEL SST-442
UHF FM BAND PROGRAMMABLE HANDHELD RADIO
MAINTENANCE / REPAIR / OPERATING MANUAL
FOR USE BY AUTHORIZED SERVICE/MAINTENANCE PERSONNEL ONLY
SST-442-MRM
REV A
COPYRIGHT 2001 RITRON, INC. • ALL RIGHTS RESERVED
RITRON, JOBCOM, and QUIET CALL, ARE REGISTERED TRADEMARKS OF RITRON, INC.
TABLE OF CONTENTS
TOPIC
SST-442
PAGE
TOPIC
PAGE
IMPORTANT MAINTENANCE/REPAIR INFORMATION .. 1
THEORY OF OPERATION
SPECIFICATIONS
INTRODUCTION ............................................................. 16
POWER SUPPLY AND VOLTAGE DISTRIBUTION........ 16
Power Strobe............................................................. 16
Low Battery Voltage Detection................................... 16
REFERENCE OSCILLATOR ........................................... 16
SYNTHESIZER .............................................................. 16
Pin Numbers.............................................................. 16
Prescaler Divider / Synthesizer Controller.................. 16
VCO / Buffer Amplifiers ............................................. 17
Oscillator Modulation ................................................. 17
DIGITAL POTENTIOMETERS......................................... 17
RECEIVER ...................................................................... 17
RF Amplifier............................................................... 17
1st Mixer.................................................................... 18
FM Receiver Subsystem............................................ 18
Voice / Tone Conditioning in Receiver Mode ............. 18
Voice Band ................................................................ 18
Sub-Audible ............................................................... 18
Audio Amplifier .......................................................... 18
ANTENNA SWITCHING / LOW-PASS FILTER ............... 19
TRANSMITTER ............................................................... 19
Keying ....................................................................... 19
+VTX Supply.............................................................. 19
Power Amplifier ......................................................... 19
Voice/Tone Conditioning in Transmit Mode ............... 19
Voice Band ................................................................ 19
Sub-Audible ............................................................... 19
MICROCONTROLLER .................................................... 20
GENERAL......................................................................... 2
CONTROLS ...................................................................... 2
TRANSMITTER................................................................. 2
RECEIVER........................................................................ 3
BATTERY ......................................................................... 3
INTRODUCTION
GENERAL......................................................................... 4
Model Identification ..................................................... 4
FCC REGULATIONS
Licensing..................................................................... 4
Safety Standards......................................................... 4
BATTERY CARE
CHARGING....................................................................... 5
PRECAUTIONS ................................................................ 5
BATTERY REPLACEMENT.............................................. 5
Fig. 1 Battery Replacement......................................... 5
BATTERY MAINTENANCE............................................... 6
BATTERY CONDITIONING .............................................. 6
OPERATION
DESCRIPTION OF CONTROLS AND CONNECTORS..... 7
Fig. 2 Controls and Accessory Connectors.................. 7
RADIO OPERATION
On-Off/Volume ............................................................ 8
Receive ....................................................................... 8
Selective Signaling Squelch ........................................ 8
Monitor ........................................................................ 8
Battery Saver .............................................................. 8
Transmit...................................................................... 8
Channel Selection ....................................................... 8
WHAT THE RADIO TONES MEAN
Power On/Self Check “OK........................................... 9
Error Tones ................................................................. 9
Channel Select............................................................ 9
Tone Squelch .............................................................. 9
Recharge Battery Alert ................................................ 9
OPTIONAL RADIO TONES
Receiver Squelch Tone ............................................... 9
Busy Channel Inhibit ................................................... 9
Transmitter Time Out .................................................. 9
BELT CLIP INSTALLATION.............................................. 9
TROUBLESHOOTING
General ..................................................................... 10
Battery ...................................................................... 10
Error Tones ............................................................... 10
Tone Coded Squelch................................................. 10
PROGRAMMING THE RADIO
PTT (PUSH-TO-TALK) PROGRAMMING
Fig. 3 Placing the Radio in Program / Readout Mode 11
Reading Out a Radio Channel’s Content................... 11
PTT Programming the Radio..................................... 12
Return To Normal Operation ..................................... 12
PTT Programming Mistakes...................................... 12
Table 1 – PTT Programming Frequency Table.......... 13
Table 2 – Quiet Call Codes and Frequencies ............ 13
COMPUTER SOFTWARE COPYRIGHTS ...................... 13
PC COMPUTER PROGRAMMING ................................. 13
Programmable Features............................................ 14
Description of Features ............................................. 15
ALIGNMENT PROCEDURE
RECOMMENDED TEST EQUIPMENT............................ 21
RADIO PREPARATION................................................... 21
REFERENCE FREQUENCY ........................................... 21
MODULATION BALANCE ............................................... 22
TRANSMITTER TONE DEVIATION ................................ 22
TRANSMITTER VOICE DEVIATION ............................... 22
RECEIVER SENSITIVITY AND SQUELCH..................... 22
RECEIVER NOISE SQUELCH ........................................ 23
SYNTHESIZER ............................................................... 23
VOLTAGE CHART
Measurement Conditions ................................................. 24
SST-442 Voltages ........................................................... 24
PARTS LIST
SCHEMATIC REFERENCE PARTS LIST ....................... 27
CASE ASSEMBLY PARTS LIST ..................................... 33
SCHEMATIC AND PART PLACEMENT DRAWINGS
TOP SIDE PART PLACEMENT....................................... 35
BOTTOM SIDE PART PLACEMENT............................... 36
SCHEMATIC – UHF RF .................................................. 37
SCHEMATIC – Signal Processing ................................... 38
IMPORTANT REPAIR / MAINTENANCE INFORMATION
SST-442
Surface Mount Repair
PC Board Removal - Special Tool
RITRON surface mount products require special
equipment and servicing techniques. Improper
servicing techniques can cause permanent damage
to the printed circuit boards and/or components,
which is not covered by RITRON’s warranty. If you
are not completely familiar with surface mounted
component repair techniques, RITRON recommends
that you defer maintenance to qualified service
personnel.
RITRON recommends using a knurled nut tool to
remove the slotted knurled nuts that secure the
charge and audio jacks on top of the radio. You will
need two sizes of this tool, one for each jack size.
Mouser Corporation  is one source, stock number
382-0004 (2.5mm jack) and 382-0006 (3.5mm jack).
You can reach Mouser sales and distribution center
at 1-800-346-6873.
Precautions for Handling CMOS Devices
This radio contains complementary metal-oxide
semiconductor (CMOS) devices, which require
special handling techniques. CMOS circuits are
susceptible to damage by electrostatic or high voltage
charges. Damage can be latent, with no failure
appearing until weeks or months later. For this
reason, take special precautions any time you
disassemble the radio. Follow the precautions below,
which are even more critical in low humidity
environments.
1)
Storage/transport - CMOS devices that will be
stored or transported must be placed in
conductive material so that all exposed leads are
shorted together. CMOS devices must not be
inserted into conventional plastic “snow” or
plastic trays of the type that are used for other
semiconductors.
2)
Grounding - All CMOS devices must be placed
on a grounded bench surface. The technician
that will work on the radio/CMOS circuit must be
grounded before handling the radio. Normally,
the technician wears a conductive wrist strap in
series with a 100K Ohm resistor to ground.
3)
Clothing - Do not wear nylon clothing while
handling CMOS circuits.
4)
Power off - Remove power before connecting,
removing or soldering a PC board that contains
CMOS devices.
5)
Power/voltage transients - Do not insert or
remove CMOS devices with power applied.
Check all power supplies to be used for testing
CMOS devices, making sure that no voltage
transients are present.
6)
Soldering - Use a grounded soldering iron for
soldering CMOS circuitry.
7)
Lead-straightening tools - When straightening
CMOS leads, provide ground straps for the tool
used.
Properly Attach the Synthesizer Shield
The synthesizer shield should not be removed, unless
a component must be replaced. This shield is
soldered to the main PC board.
Re-assembly - Speaker Magnet, Battery Voltage
on Connector Pin
The speaker magnet will pick up clipped leads and
other small metal objects from your bench top. Even
tiny objects on the diaphragm will cause the speaker
to buzz. Make sure the speaker is free of foreign
objects before reassembling the radio.
Radio Transmitter Power Measurements
The SST-442 was designed to produce 2 Watts of
Transmitter power at nominal battery voltage (+7.2
VDC), throughout the radio’s operating frequency
range. Measurements are made with the RITRON
SST-SRVBD RF service module connected to the
radio antenna terminal. The transmitter was
designed with close tolerances to prevent RF power
output from exceeding specifications and reducing
battery life.
PCB and Firmware Revisions
Changes in circuit design, component values, and
radio firmware are made occasionally to enhance the
performance of the SST-442. In general, the manual
will be periodically updated for component value
changes without a change in the manual revision
level. Always refer to the Schematic Reference Parts
List for the most recent component values. Changes
in circuit design that require printed circuit board
revision, or changes in firmware that significantly alter
the operating characteristics of the radio, will be
covered in a revised manual.
This manual is updated for the following revisions:
SST-442-MRM
Rev A
PCB Revision
1750270A
Firmware Revision
v06
SPECIFICATIONS
SST-442
CONTROLS
GENERAL
FCC ID:
AIERIT13-442
FCC Rule Parts:
22, 74, 90, 95
Frequency Range:
450 to 470 MHz
Max. Freq. Separation:
10 MHz
RF Channels:
Up to 10 Channels,
Independent TX/RX
frequencies.
Push Button Controls:
On/Volume Up, Volume
Down/Off, PTT, Channel
Speaker Beep Indicators:
Synthesizer Step Size:
12.5 KHz
Frequency Stability:
+/-2.5 PPM (-30 to +60 C)
TX/RX
Tone/Code Signaling:
CTCSS (Quiet Call)
On/Volume Up:
Radio beeps channel
number when turned on,
followed by increasing
audio to adjust volume.
Volume Down/Off:
Decreasing audio to adjust
volume, with two tones
when turned off.
Both Volume Buttons:
Alternates between Tone
Squelch (single beep) and
Carrier Squelch (two
beeps). If both buttons
are held down until the
radio beeps repeatedly,
squelch will be disabled.
PTT:
Programmable for a single
“transmit beep”.
Channel:
Number of beeps indicates
channel.
Digital Coded Squelch
(Digital Quiet Call)
Dimensions:
4.75”H x 2.2”W x 1.43”D
Weight:
11.5 oz. with battery pack
Enclosure Material:
Lexan Polycarbonate
Environmental:
Splash resistant and
shock and vibration per
RITRON Drop Test (6 ft.
drop onto concrete on all
six sides)
TRANSMITTER
RF Power Output:
2 Watts @ +7.2 VDC
Wide Mode Narrow Mode
Antenna Fitting:
1/4" - 32 x 1/4" threaded
External RF Test Jack:
Antenna connector with
RITRON SST-SRVBD test
device
Earphone Jack:
Microphone/PTT/
Chg Jack:
3.5 mm, disconnects the
internal speaker for
external earphone,
speaker / microphone, or
headset. Also provides
cable connection for PC
programming.
2.5 mm, for external
speaker/microphone,
headset or RITRON model
BC-A wall charger.
Emission Designator:
16K0F3E
Deviation:
+/- 5.00 KHz +/- 2.50 KHz
FM Hum and Noise:
-43 dB
Audio Distortion:
<3%
11K0F3E
-37 dB
Spurious & Harmonics: -50 dBc
Audio Response:
Meets FCC and EIA
requirements
Time-out Timer:
60 seconds,
programmable
SPECIFICATIONS
SST-442
BATTERY
RECEIVER
Wide band
Models
Narrow band
Models
Battery Pack:
Modulation Acceptance: +/- 7.0 KHz +/- 3.75 KHz
Sensitivity:
(12 dB SINAD)
0.25 µV
+7.2 VDC, 800 mAH
rechargeable NiCd battery
pack standard
+7.2 VDC, 1500 mAH
rechargeable MiMH
battery pack optional
0.25 µV
Adjacent Channel (EIA): -60 dB
-50 dB
Battery Drain:
Spurious Rejection:
-60 dB
-60 dB
Standby:
52 mA
Image Rejection (EIA):
-70 dB
-70 dB
Sleep:
12 mA
Intermodulation (EIA):
-56 dB
-57 dB
Avg. Standby
with Power Saver:
24 mA
Noise Squelch
Sensitivity:
Programmable per
channel, factory set for 12
dB SINAD
Receive:
125 mA
Transmit:
850 mA @ 2 Watts
Frequency Response:
Audio Output
300 - 3000 Hz, deemphasized
1 Watt into 8 Ω, with less
than 5 % THD @ the
earphone jack
Receiving System:
Dual conversion
superheterodyne
I.F. System:
1st - 43.65 MHz,
2nd - 450 KHz
L.O. Injection:
Low side
QC/DQC Decode Time:
per EIA Standards
Battery Life @ 90/5/5 Duty Cycle with
Standard battery pack (800 mAH):
12.7 Hrs, Battery Saver On
8.4 Hrs, Battery Saver Off
Battery Life @ 90/5/5 Duty Cycle with
High capacity battery pack (1500 mAH):
23.7 Hrs, Battery Saver On
15.7 Hrs, Battery Saver Off
INTRODUCTION
SST-442
FCC REGULATIONS
GENERAL
RITRON's SST-442 handheld is a small,
programmable two-way radio, designed to operate in
the 450-470 MHz professional FM communications
band. This handheld features push-button operating
controls, with the Push-To-Talk and Channel buttons
on one side of the radio. The On / Volume Up and
Volume Down / Off, volume and monitor controls are
on top.
Each radio can be “dealer” programmed to contain a
unique set of operating frequencies and options.
Selective signaling options include Quiet Call
(CTCSS) and Digital Quiet Call (DCS). Transmitter
power, operating bandwidth and battery saver are
among the options programmable on a per channel
basis.
Model Identification
The SST-442 model, serial number and FCC
Identification are displayed on a label located on the
back of the radio beneath the belt clip.
Licensing
The FCC requires the radio owner to obtain a station
license for his radios before using them to transmit,
but does not require an operating license or permit.
The station licensee is responsible for ensuring that
transmitter power; frequency and deviation are within
the limits specified by the station license. The station
licensee is also responsible for proper operation and
maintenance of the radio equipment. This includes
checking the transmitter frequency and deviation
periodically, using appropriate methods.
Safety Standards
In 1991 the Institute of Electrical and Electronics
Engineers (IEEE), and in 1992 the American National
Standards Institute (ANSI) updated the 1982 ANSI
standard for safety levels with respect to human
exposure to RF energy. Over 120 scientists,
engineers, and physicians from universities,
government health agencies, and industry, after
reviewing the available body of research, developed
this updated Standard. In March 1993 the Federal
Communications Commission (FCC) proposed the
adoption of this updated Standard.
The SST-442 handheld radio is designed to comply
with this Standard. To limit your exposure to levels
at, or below, the levels in the Standard, please
observe the following:
•
Use only the antenna(s) available from RITRON
for this model. DO NOT attempt to substitute any
other antenna.
•
Keep talk times as short and infrequent as
possible. DO NOT depress the PTT button when
not actually wishing to transmit. The radio is
equipped with an internal timer to limit continuous
transmit times.
•
When transmitting, hold the radio in front of the
mouth at a distance of at least 4 inches. DO NOT
hold the radio in such a manner that the antenna
is next to, or touching, exposed parts of the body,
especially the face or eyes while transmitting.
•
In belt mounted applications, when transmitting,
remove the radio from the belt and hold away from
the body at least 4 inches.
•
When using external headset accessories, hold
the unit away from the body at least 4 inches while
transmitting.
•
DO NOT allow children to operate the radio.
BATTERY CARE
SST-442
BATTERY REPLACEMENT
CHARGING
The handheld is powered by a rechargeable battery,
which fits into the radio case (see FIG-1).
The battery pack can lose its charge during storage
and shipment, and should be fully charged before the
radio is used. Thereafter, the battery should be
charged overnight after each day of use, to ensure
peak radio performance for the next day. Using the
cube charger (model BC-A), the battery should
charge completely in 12 hours.
To charge the battery using a RITRON cube charger plug the charger cord into the smaller of the two jacks
on top of the radio. Then plug the cube into a 110
VAC outlet. The green lamp lights while the battery is
charging, and should go off only when the cube is
unplugged.
Two charger contacts, visible through the bottom of
the radio case, allow the battery to be charged using
an optional RITRON drop-in charger (model BCCPS). The battery pack may be charged inside or
outside of the radio case.
To charge the battery using a drop-in charger (model
BCC-PS) - plug the drop-in charger into a 110 VAC
outlet. Set the portable or battery into the charger.
Each battery contact must rest on a charger contact
pin.
To replace the battery in the SST-442:
1.
Hold the radio as shown in FIG-1(A)
2.
Use your thumbnail to open the Door Latch, as
shown in FIG-1(A).
3.
Lift and rotate the Battery Access Door to release
it as shown in FIG-1(B).
4.
Use the Pull-tab to pull the Battery Pack out of
the case as shown in FIG-1(C).
5.
Insert the replacement Battery Pack as shown in
FIG-1(C). Push the Battery in as far as possible.
6.
Replace the Battery Access Door. Secure it by
closing the Door Latch as shown in FIG-1(A).
7.
Be certain to firmly lock the Door Latch, as
shown in FIG-1(A).
BATTERY
ACCESS
DOOR
LATCH
CLOSED
NOTE: A new battery must be cycled (charged and
discharged) several times before it will reach
its maximum charge capacity.
LATCH
OPEN
(A)
PRECAUTIONS
•
Use only RITRON-supplied chargers; other
chargers might cause fire, explosion, or other
damage to the radio.
•
Do not "fast-charge" a brand new battery pack.
Otherwise, the battery might be damaged.
•
Once the battery has been charged fully using
the normal rate, the fast rate may be used
thereafter.
•
Do not fast-charge a battery pack that is fully
charged. This can shorten battery life.
•
Do not charge or replace a battery in an
explosive atmosphere. Contact sparking can
ignite an explosion.
•
Do not dispose of a battery in fire. An explosion
might result.
•
Do not charge the battery in temperatures colder
than about 45°F. Electrolyte leakage can occur
and ruin the battery.
•
Charging in temperatures above approximately
95°F will not harm the battery, but can reduce its
charge capacity.
BATTERY
ACCESS
DOOR
(B)
PULL-TAB
(C)
FIG-1: Battery Replacement
BATTERY CARE
SST-442
BATTERY CONDITIONING
BATTERY MAINTENANCE
With daily use and recharging, a battery’s service life
is about one year. To ensure maximum service life,
follow these guidelines:
•
DO NOT discharge a battery that is already “run
down.” If the battery cannot power your radio,
recharge the battery.
•
DO NOT overcharge a battery. The standard
battery should not be left to charge continuously.
•
Condition battery packs once a month as
directed in Battery Conditioning.
•
Condition batteries that are run down.
•
Charge batteries for 16 hours before storage,
and for 16 hours once a month thereafter.
•
DO NOT charge batteries in temperatures colder
than about 45°F. Charging batteries in
temperatures above 95°C. does not harm them,
but can reduce charge capacity.
It is time to purchase a new battery:
•
When the radio’s transmitter coverage decreases
or does not work at all.
•
When the radio quits working after just a few
hours of use, even with a full overnight charge.
•
When the battery is more than two years old.
The date of manufacture is stamped on every
battery. The first two digits indicate the year, the
last two digits the week.
Due to the extended run time of the SST-442 radio,
some users may never fully discharge the battery
pack during normal use. Achieve maximum battery
life by fully discharging the battery periodically to
condition it.
After exposing the battery pack to many cycles of not
fully discharging it before recharging, the radio may
exhibit reduced battery capacity. This reduced
capacity is evident when, after several hours of use,
battery voltage drops while the radio is transmitting,
causing the radio to emit a dead battery warning tone
and shut itself off.
Condition battery packs by the following procedure as
either a preventive measure, or if you suspect
reduced capacity:
1.
Use your radio throughout a normal working day
without charging.
2.
Press and hold the On/ Volume Up and Volume
Down/ Off buttons simultaneously for 8 seconds
to place the radio in "open squelch" mode.
3.
Release both buttons when you hear the radio
beep rapidly; it will then emit a loud "rushing"
noise. Press On/ Volume Up to maximize this
noise.
4.
Put the radio away in a secure place (possibly a
desk drawer), where nothing can press against
the buttons to accidentally turn it off or cause it to
transmit. Allow the radio to run until it shuts off
when the battery is completely discharged. A
typical battery pack may require up to 8 hours to
completely discharge.
5.
When the radio has shut off, charge it overnight
for 12-14 hours. The battery will be ready for use
with renewed capacity.
OPERATION
SST-442
DESCRIPTION OF CONTROLS AND
CONNECTORS
Antenna
The flexible antenna radiates and receives radio
signals. Before using the radio, be sure the
antenna base is threaded fully into the radio’s
antenna bushing.
Antenna
Jack Cover
Use only the antenna(s) available from RITRON
for the SST-442. Do not attempt to substitute
with any other antenna.
Vol Down/Off
Audio
Accessory
Jack
On/Volume Up
On/Vol Up
This button switches on the radio, then increases
the volume if you continue to press.
Volume Down/Off
LD
Charge Jack
/H
FF
This button decreases the volume, then shuts off
the radio if you continue to press.
Push-To-Talk
The PTT activates the transmitter, and must be
held down while you talk into the microphone.
Release the PTT button to receive.
Channel Selector
Pressing this button selects the next channel.
When the maximum number of channels is
reached and you press this button, the radio
resets to channel 1.
Audio Accessory Jack
This jack connects speaker audio to optional
accessories, such as a remote speaker/
microphone or an earphone. For accessories
that have a two-plug connector, the smaller plug
is inserted into the charge jack.
LU
Push-to-Talk
Speaker
CH
Channel
Selector
Microphone
Battery Access
Door
(Case bottom)
Fig. 2
Battery Charger
Contacts
(Case bottom)
Controls and Accessory Connectors
This jack is also used to program the radio using
the optional PC programming kit.
Charge Jack
Jack Cover
The battery may be charged through this jack
using a standard RITRON wall socket charger
cube. This jack also connects microphone audio
to the optional remote speaker/microphone.
This rubber cover seals out dust and moisture, etc. Snap the
cover into the audio accessory and charge jack openings
when the jacks are not being used.
Microphone
The microphone converts your voice into
electrical impulses, which are carried with your
broadcast to receiving radios. Hold the radio
about four inches away and talk into the
microphone while transmitting. Shouting does
not improve the listener’s reception.
Speaker
Battery Access (Case Bottom)
The battery door on the case bottom may be removed to
access the battery. (Refer to the Battery Replacement section
of this manual.)
Drop-in Charger Contacts (Case Bottom)
Two charger contacts in the bottom of the SST-442 radio case
allow the battery pack to be charged using an optional
RITRON drop-in charger (model BCC-PS.)
The speaker allows you to hear calls on your
channel.
OPERATION
SST-442
RADIO OPERATION
On-off/Volume
To switch on the radio - press the On/Volume Up
button. The radio will beep a number of times equal
to the current channel number.
To adjust the volume - press the volume up button
until you reach the desired level. You should hear
noise and any broadcasts on the channel.
To turn off the radio - press and hold the Off/Volume
Down button until two tones sound.
To determine whether the radio is on - press the
volume down button. If the radio is on, noise or
activity on the channel is heard.
Receive
To hear calls from other users - adjust the volume as
desired. The radio can receive broadcasts while the
Push-To-Talk button is not being pressed. Whether
or not you hear these broadcasts depends upon the
squelch settings.
There are two types of squelch used in the SST-442
portable. First is carrier squelch. This lets you hear
all broadcasts on your channel strong enough for the
radio to detect, and silences noise. Second is one of
the selective signaling or “tone squelch” formats
available on the SST-442. This allows you to screen
out “on-channel” broadcasts that do not carry the
correct code programmed for the radio.
Note: It is possible that the beginning of a call might
be missed while the radio is in battery saver
mode. If this happens, ask the caller to repeat
the message.
Selective Signaling Squelch
Battery Saver
The handheld has a programmable "battery saver"
feature that conserves battery power. The battery
saver constantly checks the radio's transmitter,
receiver and controls for activity. If a number of
seconds pass without the receiver detecting a call,
and without the user operating a control, this feature
removes power from most of the radio.
During this "off-time," any activity restores full power.
Every few fractions of a second, the battery saver
applies power to the receiver, checking for
broadcasts. It is possible that the first part of an
incoming call might go unheard before activity is
detected and power restored. If this happens, the
caller can repeat his message. Once "radio contact"
is made, normal unhurried conversation can follow.
Transmit
Normally, you should not transmit until no one is
talking on the channel.
To transmit - hold down the Push-To-Talk button and
with the radio four inches away talk into the
microphone. Speak in a normal tone, since talking
louder will not improve the listener’s reception.
Channel Selection
To change channels - press and release the Channel
button. The radio will beep a number of times equal
to the current channel number. Pressing the Channel
button again will increment the channel and the radio
will beep the new channel number. For example, if
you select channel 2, the handheld will beep twice. If
the highest channel number is selected and you
press the Channel button, the radio will reset to
channel 1. A one-channel radio will beep only once
when you press the Channel button.
To activate tone squelch - simultaneously press both
of the volume buttons. Hold for a second or two
before releasing. When tone squelch is turned on,
the handheld sounds one beep. When carrier
squelch is on, the radio emits a "double beep."
Note: If you continue to hold down the volume
buttons after the beep (or double beep), the
radio will start beeping repeatedly. This
means that squelch is turned off. Release the
buttons. To restore squelch, press and hold
both of the volume buttons until the radio
sounds a beep or double beep.
Monitor
To monitor the channel - press one of the volume
control buttons. When you press the volume up or
the volume down button, squelch turns off and all
radio traffic on the channel (and noise) sounds in the
speaker.
OPERATION
SST-442
WHAT THE RADIO TONES MEAN
OPTIONAL RADIO TONES
The handheld responds to certain instructions by
sounding a beep or series of tones. These tones can
tell you whether the radio is working as you expect.
The SST-442 can be programmed using the RITRON
PC Programmer for optional alert tones.
Receive Squelch Tone
Power On/Self Check “OK”
When it is first turned on, the radio runs a quick “self
test” to confirm basic functions. The radio then beeps
the number of times equal to the channel number
selected. The radio is then ready to use.
Error Tones
However, if the “self test” detects a diagnostic error,
an error tone sounds. Alternating tones (the second
is longer and lower pitched) indicate the radio
frequency synthesizer is malfunctioning. Turn off the
radio and try again. A long, low-pitched tone means
the battery voltage is too low to operate the radio. In
this case, recharge the battery. If you cannot correct
a problem, consult an authorized Ritron service
facility or Ritron.
A short tone sounds at the end of each received
transmission to indicate that you may transmit.
Busy Channel Transmit Inhibit
If a user is transmitting on your radio frequency
without your tone, you will not be allowed to transmit.
The radio will beep a series of long, low tones while
the PTT is held down (like a busy signal).
Transmitter Time Out
A low tone followed by a higher-pitched tone sounds
and the transmitter automatically shuts off if you hold
down the PTT button longer than the programmed
Time-out. The radio automatically switches to receive
mode. Authorized service personnel can turn off this
feature.
Channel Select
When the Channel button is pressed, the radio beeps
a number of times equal to the current channel
number. Pressing the Channel button again will
increment the channel and the radio will beep the
new channel number.
Tone Squelch
BELT CLIP INSTALLATION
If you are going to attach the belt clip to the handheld,
follow these instructions:
1.
When you press and hold both Volume buttons at the
same time, a single beep will sound to indicate that
tone squelch is on. A "double beep" means that
carrier squelch is on.
Do not use petroleum solvents of any kind on the
radio. These can corrode the case.
2.
Place the belt clip on top of the radio case back,
with the screw hole in the aligned with the hole in
the radio case.
3.
Using the screw that came with this accessory,
attach the clip to the radio.
Recharge Battery Alert
As the battery voltage approaches the minimum
required “operating voltage” the radio will emit a short
beep every minute to alert the user that the battery
will soon need recharging. Once the battery charge
drops below the required "operating voltage," the
radio emits a long, low tone and turns itself off. If you
turn the radio back on, it will beep again and shut
itself off. Recharge the battery.
The belt clip is fastened to the radio case back
with the Philips head screw provided. Use the
screw included, since a longer screw might
damage the radio’s electronics.
OPERATION
SST-442
TROUBLESHOOTING
If you have trouble operating the handheld, review the
radio controls and operation sections. If you think the
radio is malfunctioning, check the following table.
GENERAL
The radio does not work at all.
•
•
Make sure the battery is installed correctly, as
shown in FIG-1.
Recharge or replace the battery. (See note 1.)
An error tone sounds while you are talking. (and
the transmitter shuts off).
•
BATTERY
The battery loses its charge sooner than
expected.
•
•
•
Operating features do not work exactly as expected.
•
The radio has been factory or dealer
programmed for customized operation.
Reception is poor.
•
•
1.
Try a battery pack from a working radio. If the radio in
question works with that pack, the original battery is
suspect. Charge the suspect battery as recommended
in this manual. Then, if the charged original battery
cannot power the handheld, try charging again with
another charger. If the battery still doesn’t hold a
charge, the pack should probably be replaced.
However, if the battery appears to be good after you try
the second charger, the first charger might be faulty. If
you think that an accessory is not operating properly,
contact your dealer or RITRON. (Radio accessories
come with a 90-day limited warranty.)
2.
Reception can often be improved by moving a short
distance. This effect is more noticeable inside of
buildings. The range of these portables equipped with
a standard battery pack is about two miles (line-ofsight).
3.
If your radio does not detect calls from other radios on
the channel, turn off tone squelch. (Press both Volume
buttons at the same time - a double beep means that
tone squelch is off.)
4.
If you want to hear a call, you must select a channel
that is programmed to receive the caller’s transmit
frequency. If you want to call another unit, you must
select a channel that is programmed to transmit the
other radio’s receive frequency. However, if you use a
repeater, your channel must be programmed to work
with the repeater’s transmit and receive frequencies.
(A radio channel can hold two separate operating
frequencies, one for Receive, the other for Transmit.)
5.
Maximum power drain occurs while the radio transmits,
so don’t hold down the Push-To-Talk button more than
necessary. Battery power is used while the handheld is
left on to receive calls. If practical, switch off the unit.
6.
In extreme cold, a battery’s charge capacity is greatly
reduced. If you use the radio in very cold weather,
periodically warm the portable underneath your coat if
possible. An optional remote speaker/microphone
would allow you to keep the radio under your coat while
transmitting and receiving.
7.
In order for radios to communicate using Quiet Call,
they must be programmed with the same tone code.
Each code is unique, and your radio will respond only
to the code programmed. Press and hold both volume
buttons at the same time. A single beep means that
tone squelch is on. A double beep means that tone
squelch is off.
Move to a different location. (Note 2.)
Confirm that the proper antenna is connected to
the radio. (See p. 11, "Antenna.")
•
Turn off tone squelch. (See Note 3.)
Be certain your radio receives on the same as
the caller transmits. (Note 4.)
Recharge the battery. (Note 1.)
Your calls cannot be heard in other radios.
•
•
Make sure that your radio transmits on the
receive frequency of the radio(s) you want to call.
(Note 4.)
Recharge the battery. (Note 1.)
TONE CODED SQUELCH
You cannot screen out calls from users outside of
your tone group.
•
•
Make sure the channel is programmed with tone
squelch.
Activate Tone (coded) squelch. (Note 7.)
You cannot hear Tone coded messages while in
Tone (coded) squelch.
•
Confirm that the channel is programmed to
detect the same code as the calling radio(s)
transmits. (Note 7.)
Others in your tone group cannot hear your tone
coded messages.
•
Verify that you transmit the same code as the
radio(s) you call are programmed to detect.
(Note 7.)
ERROR TONES
An error tone sounds when the radio is first
turned on.
•
•
Replace the battery. (Note 1.)
See "Error Tones" in the Operation section.
Review the battery charging instructions.
Conserve the battery. (Note 5.)
If the radio is used in extreme cold, warm the
radio under your coat. (Note 6.)
Notes
You cannot hear calls from other radios.
•
•
Refer to “Error Tones”
10
PROGRAMMING THE RADIO
SST-442
PROGRAMMING METHODS
Each SST-442 can be programmed to operate on up
to 10 channels. The SST-442 may be programmed
using the Push-to-Talk switch or an optional RITRON
PC programming kit.
PTT (PUSH-TO-TALK) PROGRAMMING allows you
to program any channel to one of the radio
frequencies listed in Table 1 and any Quiet Call code
listed in Table 2. The radio will transmit and receive
on the programmed table frequency and QC code.
PC PROGRAMMING allows you to program any
frequency within the band and channel spacing of the
radio model. This method also lets you customize the
handheld with optional operating features.
PTT (PUSH-TO-TALK) PROGRAMMING
Note: If the radio will not enter PTT program mode,
this feature has probably been turned off using the
optional PC programming kit.
Fig. 3 PLACING THE RADIO IN PTT
PROGRAM / READOUT MODE
Reading Out a Radio Channel’s Contents
1.
Place the radio in Program / Readout mode as
described in Fig-3.
2.
Press the Channel Selector button to select the
radio channel you would like to read out.
3.
Press and release the Volume Up button.
4.
The radio will emit a series of beeps, pause, and
then begin another series. Four series of beeps
will be heard, with each series representing a
digit. The number of beeps in a series is equal
to the digit. (See CHANNEL READOUT)
5.
Write down each digit while the radio pauses.
List the digits in the order that you hear them.
6.
The first two digits represent the frequency as
shown in Frequency Table 1 on page 13.
7.
The second two digits represent the QC
(CTCSS) tone frequency as shown in Quiet-Call
Tone Code Table 2 on page 13.
8.
To read out another channel, follow steps 2
through 7.
9.
CHANNEL READOUT:
FREQUENCY CODE
st
1 digit
# of beeps
in series
1.
Ten (10) beeps = the digit zero (0)
2.
The radio will beep out “44” as a tone code if it
has been programmed for “No Tone”.
3.
A radio that has been PC-programmed with any
frequency not listed in Frequency Table 1, page
13, will emit the error tone on content readout.
nd
digit
# of beeps
in series
∗
TONE CODE
rd
3 digit
# of beeps
in series
Turn the radio off to exit Channel Readout mode.
Notes:
∗
∗
th
4 digit
# of beeps
in series
♦
Notes:
∗
Pause after entering each digit. The radio
will emit a low tone, separating one digit
from the next.
♦ The radio sounds a triple beep when PTT
channel programming is complete.
11
PROGRAMMING THE RADIO
SST-442
PTT Programming a Radio Channel
Four valid digits must be entered for the radio to
accept PTT programming. The first two digits entered
are the frequency code from Table 1, followed by the
two digits for the QC code from Table 2.
1.
Place the radio in Program / Readout mode as
described in Fig-3 on page 11.
2.
Press the Channel Selector button to select the
radio channel you would like to program.
3.
Enter the first digit by pressing the PTT button
the number of times equal to the digit’s value.
4.
Pause after the digit is entered, a low tone will
sound indicating that the digit has been
accepted.
5.
Enter the second, third and fourth digits using the
same method as the first digit.
6.
Press the Volume Up button to enter the new
channel programming. The radio will emit a triple
beep confirmation tone to indicate that
programming has been accepted.
7.
To program another channel, follow steps 2
through 6.
8.
Turn the radio off and then on again – the radio
is now ready for use.
PTT CHANNEL PROGRAMMING:
FREQUENCY CODE
st
1 digit
# of beeps
in series
∗
nd
digit
# of beeps
in series
∗
TONE CODE
rd
3 digit
# of beeps
in series
∗
th
4 digit
# of beeps
in series
♦
Notes:
∗ Pause after entering each digit. The radio
will emit a low tone, separating one digit from
the next.
♦ The radio sounds a triple beep when PTT
channel programming is complete.
Notes:
1.
To enter the digit zero ( 0 ), press the PTT ten
times.
Return to Normal Operation
2.
Program “44” to enter “No Code” for Quiet Call.
You must enter “44” to match radios not having
tone codes.
After you finish programming, turn the radio off and
then on again. The radio will beep when it is ready for
normal operation.
3.
An error tone will sound if you attempt to save an
incorrect digit. Turn the radio off, check the
digits you are attempting to enter, then start over
again.
4.
If you make a PTT click error, turn the radio off
then on, and start over.
5.
If the radio does not emit a confirming triple tone
when you attempt to enter Program / Readout
mode, the radio was dealer customized to
disable PTT programming.
6.
Refer to the Frequency Table 1 and Tone Code
(Quiet Call) Table 2 on page 13.
PTT Programming Mistakes
An error tone means that
Invalid Entries
you tried to save an invalid entry. No programming
changes are made in this case. A triple tone will
sound next indicating that the radio is still in
programming mode, and ready for an entry.
If you press the PTT five
PTT Entry Mistakes
times when you intended four, for example, or if you
just lose count, do not press the Volume Up button to
store the entry. Instead, start over by turning the
radio off and placing the radio in programming mode
again.
12
PROGRAMMING THE RADIO
SST-442
COMPUTER SOFTWARE COPYRIGHTS
Code
Frequency
Description
01
02
03
04
05
06
07
08
09
10
11
12
467.7625
467.8125
464.5500
464.5000
467.8500
467.8750
467.9000
467.9250
469.2625
462.5750
462.6250
462.6750
Yellow Dot
Brown Dot
Silver Star
Gold Star
Red Star
Blue Star
White Dot
Black Dot
Orange Dot
Table 1 – PTT Programming Frequency Table
QC
Code
Freq
(Hz)
QC
Code
Freq
(Hz)
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
67.0
71.9
74.4
77.0
79.7
82.5
85.4
88.5
91.5
94.8
97.4
100.0
103.5
107.2
110.9
114.8
118.8
123.0
127.3
131.8
136.5
141.3
146.2
151.4
156.7
162.2
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
167.9
173.8
179.9
186.2
192.8
203.5
210.7
218.1
225.7
233.6
241.8
250.3
69.4
159.8
165.5
171.3
177.3
No Tone
183.5
189.9
196.6
199.5
206.5
229.1
254.1
Table 2 – Quiet Call Codes and Frequencies
The RITRON, Inc. products described in this manual
include copyrighted RITRON, inc. computer
programs. Laws in the United States and other
countries grant to RITRON, inc. certain exclusive
rights in its copyrighted computer programs, including
the exclusive right to distribute copies of the
programs, make reproductions of the programs, and
prepare derivative works based on the programs.
Accordingly, any computer programs contained in
RITRON, inc. products may not be copied or
reproduced in any manner without the express written
permission of RITRON.
The purchase of RITRON, inc. products does not
grant any license or rights under the copyrights or
other intellectual property of RITRON, inc., except for
the non-exclusive, royalty fee license to use that
arises in the sale of a product, or as addressed in a
written agreement between RITRON, inc. and the
purchaser of RITRON, inc. products.
PC COMPUTER PROGRAMMING
RITRON’s programming kit allows programming of
the SST-442 model radios using a PC compatible
computer. An adapter cable connects the radio to a
computer’s serial communications port. Once the
cable is hooked up, the user inserts the diskette
provided into his computer’s floppy disk drive and
loads a software program.
This program transfers data between radio and
computer memory, and includes on-screen
instructions and help. Radio data may be saved to
the computer’s hard disk in order to program other
radios.
The PC Programming Kit Includes:
1)
Ritron Transceiver programming software, which
is contained on 3.5" diskettes.
2)
Installation instructions and a registration form.
3)
Ritron PC to radio adapter cable, which is
terminated at one end with a DB-25F connector,
at the other end with a modular plug. The DB-25
plugs into the computer’s serial port, the modular
plug into the SST-SRVBD modular jack.
4)
An adapter for use with SST-442 portables. This
adapter mates the modular plug to a 3.5 mm
plug, for connection to the handheld audio jack.
The PC Programming Kit Requires:
A PC compatible computer with Windows 95 or later.
The computer must have an RS-232 serial port and a
minimum of 2MB available on the hard disk drive for
installation.
13
PROGRAMMING THE RADIO
SST-442
Programmable Features
Descriptions of Features
The following features may be programmed on a per
channel basis, or will affect all channels together.
Automatic Inactivity Turn-off - The radio automatically
shuts itself off if four hours go by without the microcontroller detecting input from the volume, PTT or
channel controls.
Feature
Range
Factory
Per
Setting Channel
Automatic Inactivity
Turn-off
Y-N
Battery Saver Enable
Y-N
Battery Saver Off Time
(seconds)
0–8
Beep Volume Level
(Fixed or Controlled)
F-C
Beep Fixed Level
(percent of full volume)
0 – 100%
50%
Busy Channel TX Inhibit
Y-N
√
Carrier Only, No Codes
√
S–F
Channel Selection Mode
(Increment or Enter)
I–E
Digital Tone Invert RX
Y-N
√
Digital Tone Invert TX
Y-N
√
√
Disable Monitor
Y-N
√
Number of Channels
0 – 10
Narrow Band Channel
Y-N
√
PTT Programming
Enabled
Y–N
Quiet Call (CTCSS)
See Table 2
√
Receive Squelch Tone
Y-N
√
Squelch Tightener
0-7
√
TX Time-out Enabled
Y–N
0 – 255
60
Y-N
Channel Beep Rate
(Slow or Fast)
Digital Quiet Call (DCS)
TX Time-out Timer
(seconds)
Turn On To Medium
Volume Level
Battery Saver - Enabling this option allows the radio
to go into battery saver mode when the radio remains
idle. The power saver begins after eight seconds of
inactivity.
Battery Saver Off Time - This is the cycle time that
the radio is off in battery saver mode before it checks
for a received signal. A long Battery Saver Off Time
may cause the user to miss the beginning of the first
message when in battery saver mode.
Beep Volume Level - The radio can be programmed
for a fixed beep volume or for a beep volume that is
adjusted with the Volume controls. If fixed beep
volume is selected, the fixed level can be set between
0 – 100%.
Busy Channel Transmit Inhibit - This keeps the radio
from broadcasting if the channel is busy, and is often
used in conjunction with Disable Monitor. If you press
the PTT when the channel is busy with a signal not
intended for your radio (not carrying your tone code),
this feature sounds a "busy" tone in the speaker and
keeps the transmitter turned off.
Channel Beep Rate - The rate at which the channel
indicator beeps occur can be set to fast or slow.
Channel Selection Mode - This feature allows the
channel selector to increment or enter the channel.
The channel number is "beeped out" when the
channel button is first pressed. The channel is not
changed. In increment mode the radio is changed to
the next available channel if the channel button is
pressed again within three seconds. In enter mode
the user must press the channel button the number of
times equal to the channel they wish to select.
Digital Quiet Call RX Invert - The programmed code
is inverted for receive mode only.
Digital Quiet Call TX Invert - The code is inverted for
transmit mode.
Disable Monitor - This function may be programmed
to keep the radio user from listening to other
licensees on a shared channel. QC or DQC must be
used for this option to have any affect, and the
Encode Only feature disabled.
Maximum Number of Channels - The number of
channels available on the radio can be set from 1 to
10.
Narrow Band Channel - Any channel can be set to
operate in narrow band mode, reducing the transmit
deviation to 2.5 KHz.
PTT Programming Mode Enabled - This feature
allows channel programming from a table of predetermined frequencies using the radio PTT switch.
14
PROGRAMMING THE RADIO
SST-442
Quiet Call (CTCSS) - Programming a Quiet Call code
allows you to screen out transmissions that do not
carry your code. Your code is broadcast when you
press the PTT to make a call.
Quiet Call Encode Only - The Quiet Call code
programmed for the channel is transmitted with your
calls. However, no Quiet Call code is programmed
for receive mode, allowing all traffic on the channel to
be heard.
Receive Frequency - The radio frequency that
receives broadcasts from other units.
Receive Squelch Tone - The receiving radio beeps at
the end of each received transmission.
Squelch Tightener - This feature reduces distant "cochannel" or other interference for channels that are
not programmed with Quiet Call. Carrier squelch is
set for maximum sensitivity at the factory, but may be
adjusted to mute weak signals
Transmit Frequency - The radio frequency that
broadcasts to other units.
Transmit Time Out Timer - This feature automatically
shuts off the transmitter (ending your call) if you hold
down the PTT button continuously for 60 seconds.
The radio sounds a tone when the transmitter shuts
off.
Turn On To Medium Volume Level - The volume level
is at mid-range when the radio is first turned on.
Normally, the volume level is low when the radio is
turned on.
15
THEORY OF OPERATION
INTRODUCTION
The SST-442 is a four-channel handheld transceiver
built on a single multi-layer printed circuit board. Both
sides of the main printed circuit board are populated
with components, with the bottom side containing
only surface mounted components.
The SST-442 is frequency synthesized, with all
functions of the radio controlled by microcontroller.
POWER SUPPLY AND VOLTAGE DISTRIBUTION
The SST-442 is powered by an internal 6-cell
rechargeable battery pack. The battery pack supplies
power to the radio via two contact terminals that are
connected to the PCB through P302. F301 is a 3A
fuse in series with P302 for short circuit protection.
The battery pack may be charged through 2.5 mm
charge jack J301 via CR302 and F301. Zener diode
CR301 prevents the batteries from discharging
through the charger accessory, stops a reverse
voltage from being applied to the battery pack
through J301, and prevents a high voltage from being
applied to the radio circuitry.
SW301 ON/VOL UP switch is pressed to turn on the
SST-442, turning on voltage pass transistor Q304 via
R302 and CR303. Q304 supplies power to IC309, a
+5 VDC regulator used to power microcontroller
IC301. Pin 13 of IC301 turns on Q303, which keeps
Q304 turned on after SW301 has been released.
Power is removed from the SST-442 by pressing the
VOL DN/OFF switch SW302 until a beep is heard
from the speaker, at which time Q304 is turned off.
+5 VDC regulator IC309 supplies power directly to
microcontroller IC301, bilateral audio gates IC304,
reference oscillator Y302, synthesizer IC401, and
PTT detect transistor Q302.
The T/R output at Pin 11 of IC301 lets Q101 switch
the regulated +5 VDC to the receiver. Pin 11 of
IC301 will also turn on Q202, which turns on voltage
pass transistor Q204. With Q204 emitter connected
to the +VBATT battery supply, the collector output is
connected to the emitter of Q202 through voltage
divider R202/R203, whose values are selected to limit
the TX+V voltage to +6 VDC.
Power Strobe
The SST-442 handheld includes a power strobe
feature, which reduces battery current drain by
periodically removing voltage from part of the radio.
The strobe off cycle time is programmable using the
PC Programming Kit. The +5V SW power strobe
output at Pin 10 of IC301 controls Q306, which
switches the regulated +5 VDC to the audio
processing circuitry and the synthesizer circuitry.
This includes IC303A 2.5 VDC (Vag) for bias on
audio processing circuitry, IC303C audio high pass
filter, IC308 and IC305A audio low pass filter for subaudible frequencies, IC305B audio limiting amplifier,
SST-442
IC306 digital potentiometers, IC303B audio summing
node amplifier, and IC303D audio low pass filter.
Low Battery Voltage Detection
Battery voltage is measured at A/D input Pin 16 of
IC301 through voltage divider R303/R305. The radio
will emit a periodic beep if low battery voltage is
detected, and will turn the radio off if the battery
voltage drops below +5.2 VDC. This is to protect the
microcontroller and its EE memory from corruption
due to low supply voltage.
REFERENCE OSCILLATOR
Reference oscillator Y302 is a 1.5 ppm temperature
controlled, voltage controlled oscillator (TCVCXO)
operating at 14.4 MHz. The Pin 4 output of the
TCVCXO provides a reference for the frequency
synthesizer IC401 at Pin 20. IC401 is programmed to
provide an output at Pin 1 that is ¼ of the reference
(3.6 MHz), which is applied as a reference oscillator
to Pin 27 of IC301 microcontroller. The Y302 pin 4
output is also multiplied up to 43.2 MHz by Q105 and
its associated circuitry to provide a receiver 2nd local
oscillator signal.
SYNTHESIZER
The SST-442 radio is built around a common phaselocked loop (PLL) that consists of a voltage-controlled
oscillator (VCO) and a frequency synthesizer. The
PLL generates both the receiver 1st local oscillator
and transmitter carrier signals. Control signals from
microcontroller IC301 and Reference oscillator Y302
are routed to frequency synthesizer IC401 per the
following chart:
Pin Numbers
Clock
Data
Latch
LD
T/R SW
REF IN
REF OUT
+5 SW
+5V
IC301
12
20
12
11
27
10
1, 15, 28
Y302
IC401
18
19
17
20
12
5, 14
Q404, CR401, C414 and associated components
provide a filtered supply for the VCO oscillator and
buffer amplifiers.
Prescaler Divider / Synthesizer Controller
IC401 contains both a prescaler and synthesizer
controller. The prescaler squares and divides the
VCO output present at pin 11 by either 64 or 65,
determined by a synthesizer controller logic signal.
The exact number of times the prescaler is instructed
16
THEORY OF OPERATION
to change divisors is determined by the channel
frequency.
IC401 contains a digital phase detector that works as
follows: when an operating channel is changed or the
receive/transmit mode switched, a new synthesizer
operating frequency is selected. Microcontroller
IC301 clocks new data into IC401 internal buffer in
synchronization with clock pulses. The channel
information is stored in EE memory of IC302 and is
loaded into RAM when the channel is selected.
Once new data is loaded into the buffer, a single
pulse from IC301 appears at IC401 to instruct the
synthesizer controller to latch and execute the new
data. IC401 utilizes internal circuitry to determine
whether the present VCO output frequency is correct
by comparing the phase and frequency of the VCO
signal at Pin 11 to the 14.4 MHz reference oscillator
at Pin 20. IC401 produces an output signal at Pin 6,
a single-ended phase/frequency detector output,
proportional to the phase difference between the two
input signals.
The loop filter C429, C427, R419, R420, R418, and
C426 transform the Pin 6 output signal to a DC
voltage for application to the VCO tuning varactor
CR402. The synthesizer system is “locked” when the
phase and frequency of both the reference and the
divided VCO signal are the same.
The maximum amount of current this output can sink
or source is determined by the value of R421 tied to
Pin 8 of IC401, with the output current programmable
to 25, 50 or 100% of maximum.
VCO / Buffer Amplifiers
Q403, L401, CR402 and associated components
form the VCO (Voltage Controlled Oscillator), a
resonant circuit that oscillates at frequencies from
416 MHz in receive (receive frequency - 43.65 MHz)
to 470 MHz in transmit. Varying the voltage at CR402
changes the varactor capacitance, which in turn
alters the VCO output frequency.
When in transmit mode a +5 VDC T/RSW signal is
applied to Q406, which turns on Q405 to draw current
through pin diode CR404 and L403. With CR404
biased on, L402 is effectively shorted to ground,
shifting the VCO frequency up 43.65 MHz.
Q401 and Q402 are buffer amplifiers, with Q401
feeding in the input of the synthesizer at Pin 11, the
receiver 1st local oscillator and the transmitter preamplifier.
Oscillator Modulation
When the SST-442 is in transmit, modulation balance
control IC306E passes TX audio through to the VCO
modulation input at R416. TX audio is applied to
varactor CR403 to modulate the VCO. TX audio is
also routed to the Pin 1 input of TCVCXO reference
oscillator Y302. Low frequency tones modulate the
reference oscillator because the synthesizer is not
able to track them.
SST-442
DIGITAL POTENTIOMETERS
IC306 contains 6 digital potentiometers programmed
by IC301, sharing the same clock and data outputs
used by the synthesizer and a separate Digital Pot
Latch signal from Pin 8. The digital potentiometers
are used in conjunction with IC303B, a summing
node amplifier used for modulating the VCO and
reference oscillator. IC306A, B, D, E, and F can only
be changed through serial programming, and can
only be performed by an authorized licensed RF
technician.
IC306A is connected through R352 to the Pin 6 input
of IC303B. IC306A adjusts the DC output of IC303B
to tune the reference oscillator frequency.
IC306B is unused.
Volume control IC306C applies the processed voice
band signals at IC303D to audio amplifier IC307
when in receive mode. Depressing the ON/VOL UP
switch SW301 increases the setting of IC306C while
VOL DN/OFF switch SW302 decreases it.
Transmitter tone deviation control IC306D applies the
output of the selective signaling low-pass filter IC308
to the Pin 6 input of IC303B through R350. IC306D is
completely closed in receive mode.
Transmitter modulation balance control IC306E is
used to apply the Pin 7 output of IC303B to the VCO
modulation input. This will set the ratio of the
modulating signal applied to the VCO and the
reference oscillator. IC306E is completely closed in
receive mode.
Transmitter voice deviation control IC306F applies
the processed voice band signals at IC303D to the
Pin 6 input of IC303B through R349. IC306F is
completely closed in receive mode.
RECEIVER
As mentioned before, Q101 switches the regulated
+5 VDC to the receiver. The +VRX receiver voltage
is switched at the strobe duty cycle if programmed for
power strobe.
RF Amplifier
A received signal from the antenna passes through a
low-pass filter (L207, C216, C217, L206, C101, and
C202) to the receiver headend. L101 and the
associated capacitors form a bandpass filter ahead of
low-noise RF amplifier Q102. L101 and C103 provide
a notch at the image frequency, 87.3 MHz below the
receive frequency. The amplified RF signal is applied
to a 2-pole bandpass filter consisting of L103, L104,
and associated capacitors. This circuit can be tuned
for any 10 MHz band between 450 and 470 MHz.
17
THEORY OF OPERATION
1st Mixer
The amplified received input signal is applied to the
gate of FET mixer Q103. The 1st local oscillator
signal from the synthesizer module is applied to the
source of Q103. L106, C117 and C118 tune the drain
output of Q103 to 43.65 MHz and apply it to YF101, a
43.65 MHz two-pole crystal filter. Q104 and
associated components amplify the 43.65 MHz IF
signal and apply it to the input of the 2nd mixer at Pin
16 of IC101.
FM Receiver Subsystem
A multi-function integrated circuit, IC101 and
associated components for the FM-receiver
subsystem. The subsystem performs the following
functions: 1) 2nd mixer, 2) 2nd IF amplifier, 3) FM
detector, and 4) noise amplifier.
The Pin 4 output of 14.4 MHz reference oscillator
Y302 is multiplied up to 43.2 MHz by Q105 and
associated components. This signal is applied to the
2nd local oscillator input at Pin 1 of IC101. The 43.65
MHz signal at Pin 16 and the 2nd local oscillator are
mixed, with the resulting 450 KHz output signal
appearing at Pin 3. This signal is filtered by a 450
KHz 6-pole ceramic filter YF102 and applied to the
input of the limiting IF amplifier at Pin 5. IC101 Pin 6
is the de-coupled input to the IF amplifier, Pin 7 the
limited IF output signal. An internal quadrature
detector, whose center frequency is determined by
450 KHz quadrature coil T101, detects the FM IF
signal. One input of the quadrature detector is
connected internally to the IF signal at Pin 7, while
the other input is the phase-shifted signal from T101
at Pin 8.
Demodulated audio appears at Pin 9, where a lowpass filter (R114, C130) removes spurious quadrature
output prior to application to the voice/tone
conditioning audio circuitry. Demodulated audio from
Pin 9 is applied to the Pin 10 input of a noise
filter/amplifier consisting of R112, C123, C124, R110,
R111 and R113. The Pin 11 output of the noise
amplifier is applied to a biased noise detector CR103,
with the output connected to an A/D input of IC301 at
Pin 19. The SST-442 is serial programmed to set the
squelch threshold and hysteresis.
Voice / Tone Conditioning in Receive Mode
SST-442 audio conditioning filter circuits are shared
with the transmitter. The same high-pass
filter/amplifier (IC303C and associated components)
used in receive voice band conditioning is used in the
transmit band. Similarly, the low-pass filter (IC308
and associated components) used for selective signal
tone decode filtering is also used for selective signal
encoding. Altering circuit configuration with bilateral
switches IC304A, B and C permits the use of the
same audio filtering system for both transmit and
receive modes.
After R114 and C130 remove the 450 KHz element
from the demodulated audio output at Pin 9 of IC101,
SST-442
C333 couples the audio signal to bilateral switch
IC304C for subaudible tone detection and connection
to IC304A for voice band audio processing.
Voice Band
Bilateral switch IC304A passes the received audio
signal to the input of IC303C, which along with its
associated components for a high-pass filter/amplifier
circuit that attenuates audio signals below 300 Hz.
The output of IC303C is applied to the input of
IC305B limiting amplifier. Bilateral switch IC304B is
switched in receive to insert C351 into the feedback
circuit of IC305B, providing de-emphasis of the
received audio signal. Bilateral switch IC304B also
removes R335 from the Pin 6 input to reduce the gain
and prevent limiting.
The output from IC305B is applied to the input of
IC303D, which along with its associated components
form an 18dB/octave low-pass filter for frequencies
above 3000 Hz.
The output of IC303D is connected to IC306C volume
control prior to connection to audio amplifier IC307.
The output of IC303D is also connected to IC306F
voice deviation control, which is completely closed in
receive mode to prevent received signals from
modulating the VCO and reference oscillators.
Audio frequency tones from Pin 24 of microcontroller
IC301 are applied to the Pin 6 input of IC305B to
provide the SST-442 alert tones.
Sub-Audible
Bilateral switch IC304C passes the received audio
signal to the input of IC305A, which amplifies the
signal and applies it to the Pin 2 input of IC308, a 5pole low-pass filter that attenuates frequencies above
250 Hz.
The output at Pin 5 is applied to an A/D input of
IC301 at Pin 18 for tone decoding. An internal digital
signal processing routine programmed into
microcontroller IC301 is used to decode the correct
selective signaling code. The output at Pin 5 of
IC308 is also connected to tone deviation control
IC306D, which is completely closed in receive mode
to prevent received subaudible tone signals from
modulating the VCO and reference oscillators.
Audio Amplifier
Receive audio from volume control IC306C is applied
to the Pin 2 input IC307, a 1 Watt audio amplifier.
C365 couples the Pin 5 output to the internal 8Ω
speaker SP301 via audio jack J303.
Microcontroller IC301 Pin 22 switches DC power to
the audio amplifier by turning on Q07, which then
turns on pass transistor Q308 to apply battery voltage
to Pin 6 of the audio amp. CR307 prevents an
inadvertent DC voltage at J303 from damaging the
audio amplifier.
18
THEORY OF OPERATION
ANTENNA SWITCHING / LOW PASS FILTER
A low-pass filter comprised of filter L203, C213,
C214, L204, C217, L207, and C216 removes
harmonics from the transmitter output before applying
the RF signal to the antenna. Received signals pass
through the low-pass filter before entering the
receiver RF amplifier circuitry.
Two PIN diodes (CR201, CR101) and associated
components form the antenna switching circuit. With
the SST-442 in receive mode, no voltage is applied to
the PIN diodes and they do not conduct. This reverse
biases CR201 to prevent the transmitter amplifier
from affecting the receiver tuning and removes
CR101 from the receiver input. Incoming signals
from the antenna pass through the low-pass filter,
then L206 and C102 to the receiver headend.
When the SST-442 is switched into transmit mode,
transmitter supply voltage is switched on by Q201
and Q202 and applied to R207. Current flows
through R207, L205, CR201, L206 and then CR101
to ground, forward biasing the PIN diodes. CR201
passes transmitter RF power to the antenna while
CR101 shunts the receiver RF amplifier input to
ground. L206 provides sufficient impedance to
isolate the transmitter power from the receiver RF
amplifier.
TRANSMITTER
Keying
The SST-442 transmitter is keyed when PTT switch
SW304 is depressed. Electret condenser
microphone M301 is connected in series to ground
with the PTT switch, which when depressed draws
current through M301, SW304, CR304 and R307 to
turn on pass transistor Q302. Q302 then turns on
Q301 to pull the TX Key Pin 2 input of microcontroller
IC301 low. The microcontroller T/R output at Pin 11
then goes high to turn on Q202, which turns on pass
transistor Q201 to apply +6VDC to the transmitter as
described previously. The transmitter can also be
keyed through J301 with an audio accessory that
inserts a microphone and PTT switch in series to
ground, drawing current through CR304.
+VTX Supply
With the transmitter enabled as described above, the
+VTX voltage from Q201 is applied to transmitter RF
amplifiers Q203 and Q204. +VTX supply also
forward biases the PIN switching diodes CR201 and
CR101 as previously described. The transmitter RF
final amplifier Q205 is powered by the battery supply.
SST-442
Power Amplifier
Q203, Q204 and associated components amplify the
VCO signal and apply it to the input of RF Final
amplifier transistor Q205. The collector output of
Q205 is matched to the antenna switching circuitry
and applied to the antenna through the low-pass
filter.
Voice / Tone Conditioning in Transmit Mode
SST-442 audio conditioning filter circuits are shared
with the receiver. The same high-pass filter/amplifier
(IC303C and associated components) used in receive
voice band conditioning is used in the transmitter
voice band. Similarly, the low-pass filter (IC308 and
associated components) used for sub-audible tone
decode filtering is also used for tone encode. Altering
circuit configuration with bilateral switches IC304A, B
and C permits the use of the same audio filtering
system for both transmit and receive modes.
Voice Band
M301 microphone audio is passes through CR304,
C334 and is switched by IC304A to the input of
IC303C, which along with its associated components
form a high-pass filter/amplifier circuit that attenuates
audio signals below 300 Hz. The output of IC303C is
applied to the input of IC305B limiting amplifier.
Bilateral switch IC304B switches R335 in parallel with
R336, raising the gain of limiting amplifier IC305B for
full limiting of the transmitter voice audio. The output
of IC305B is applied to the input of IC303D, which
along with its associated components form an 18
dB/octave low-pass filter for frequencies above 3
KHz. The output of IC303D is applied to voice
deviation control IC306F, which sets the level of the
processed transmitter audio applied to summing node
amplifier IC303B used to modulate the VCO and
reference oscillator.
Sub-Audible
Microcontroller IC301 generates the sub-audible
selective signaling encode waveforms at Pin 21 and
applies them to the input of buffer amplifier IC305A.
The output of IC305A is applied to the input of IC308,
a 5-pole low-pass filter that attenuates frequencies
above 250 Hz. C342 and C343 set the corner
frequency of the low-pass filter, with C342 switched in
by Pin 7 of IC301 to lower the corner frequency for
lower tones. The output of IC308 is applied to tone
deviation control IC306D, which sets the level of the
transmitter sub-audible encode tones applied to
summing node amplifier IC303B used to modulate
the VCO and reference oscillator.
The Pin 11 T/R output of microcontroller IC301 can
be PC programmed to hold the transmitter on after
the PTT switch has been released to allow tone
related turn-off codes for squelch tail elimination.
19
THEORY OF OPERATION
MICROCONTROLLER
The SST-442 handheld transceiver is electronically
controlled by IC301, an 8-bit microcontroller. IC301
has four 8-bit A/D inputs for processing analog
signals.
PIN DESCRIPTION
1 RESET is connected to the SST-442 +5V to start
the radio in a known state on power up.
2 TX KEY input is pulled LOW when either the
internal or external PTT switch is pressed to
initiate transmitter operation.
3 AUDIO GATE ENABLE controls analog switches
IC304A and B to configure the shared audio
processing circuitry for receive operation when
LOW, and for transmitter operation when HIGH.
SERIAL DATA INPUT links the microcontroller to
communications from an external data terminal
via J303 RING connection. This allows
programming of the SST-442 EEPROM memory
used to store channel frequency and
configuration information.
DATA output sends serial data to frequency
synthesizer IC401 to program frequency
information, IC302 EEPROM memory, and to
IC306 to set the digital potentiometers.
EECLOCK output sends serial data clock pulses
to EEPROM IC302 when reading or writing.
LOW-PASS CUT-OFF output goes LOW to lower
the cut-off frequency of IC308 when the radio is
on a channel programmed for a CTCSS tone
below 150 Hz. This output is in a tri-state OPEN
condition for all other tones.
DIGITAL POT LATCH sends a single positive
pulse after data has been sent to IC306 to latch
the new data and change the digital
potentiometers to the new programmed settings.
LED output goes LOW when the radio is on
channel 1 and is HIGH for all other channels.
10 +5V SW output goes HIGH at a programmable
periodic rate to remove the +5VSW supply from
various circuits in the radio, thus conserving
battery life. In normal transmit or receive mode
this output is LOW.
11 T/R SWITCH output is connected to the
Synthesizer circuitry to shift the frequency of the
VCO oscillator used in both transmit and receive.
The output is HIGH in transmit and LOW in
receive. T/R output is also used to switch supply
voltage to the transmit and receive circuits.
SST-442
13 +V SW output is HIGH when the radio is turned
on, keeping pass transistor Q304 turned on via
Q303 to supply power to the radio.
14 GROUND
15 VREFH sets the upper reference level for the A/D
and is connected to the regulated +5 VDC.
16 A/D input BATTERY is used to measure the
battery voltage for low and dead battery
detection. This input also serves as the ON/VOL
UP input, and is pulled LOW when SW301 is
depressed to turn on the radio and raise the
receiver speaker audio level.
17 A/D input VOL DN/OFF is pulled LOW when
SW302 is depressed to lower the receiver
speaker audio level and turn off the radio. This
input also serves as CHANNEL input, and goes
to 2.5 VDC when channel selector switch SW303
is pressed to change the radio to the next
programmed channel.
18 A/D input TONE DECODE accepts the received
QC (CTCSS) and DQC (DCS) waveforms after
signal processing for decode analysis.
19 A/D input RSSI is used to measure the output
voltage of the noise filter for squelch detection.
20 LATCH output goes LOW to allow serial data to
frequency synthesizer IC401 and goes HIGH to
latch the data, allowing the synthesizer to
execute the new frequency information.
21 TONE ENCODE outputs generate the QC
(CTCSS) and DQC (DCS) encode waveforms for
signal processing prior to modulating the VCO in
transmit mode.
22 AUDIO AMP ENABLE output goes HIGH to apply
power to audio amp IC307 for receiver speaker
audio or radio alert tones.
23 RX AUDIO GATE ENABLE switches IC304C for
receive operation when LOW, and for transmitter
operation when HIGH.
24 BEEP output generate the radio alert tones
heard in the speaker.
25 See Pin 4
27 REFERENCE OSCILLATOR INPUT has the 3.6
MHz reference signal from the synthesizer.
28 +5 VDC VDD supply voltage.
12 CLOCK output sends serial data clock pulses to
frequency synthesizer IC401 and digital
potentiometers IC306 when programming these
devices.
20
ALIGNMENT PROCEDURE
WARNING!
SST-442
7)
An authorized RF service technician must perform
test and alignment of the SST-442. Do not attempt
service of the SST-442 if not completely familiar with
the operation of frequency synthesized radio
operation. The SST-442 can operate in both Narrow
Band (2.5 KHz deviation) and Wide Band (5 KHz
deviation) systems.
RECOMMENDED TEST EQUIPMENT
1)
0 to +15 VDC, 2A current-limited power supply
2)
RF Communications Test Set (to 470 MHz) with:
FM Deviation Meter
RF Wattmeter
Frequency Counter (to 470 MHz)
SINAD Measuring Device
3)
Oscilloscope (to 20 MHz)
4)
VTVM or DMM
5)
RITRON PC Programming Kit
6)
RITRON SST-SRVBD Test Module
Make sure the radio battery is fully charged.
2)
Install the RITRON SST-SRVBD test assembly
and serial programming cable as follows:
SELECT
Alignment
Frequency
Transmit frequency
Mod Bal
Modulation balance
Tone
QC/DQC tone encode deviation
wide and narrow band
Voice
Voice deviation with no tone
wide and narrow band
Voice deviation with tone
wide and narrow band
8)
After you have completed alignment of the SST442, turn the radio off. This will remove the test
frequencies and return to operation on the
customer’s programmed frequencies.
REFERENCE FREQUENCY
1)
Make sure the unit has been switched on and is
at room temperature (approximately +25° C)
2)
Select “Frequency” from the PC Programmer
“Alignment” screen.
3)
Set the RF communications test set to the
Alignment Frequency on the Alignment screen.
4)
Press the “Tune” button on the Alignment screen
to activate the transmitter.
RADIO PREPARATION
1)
Press the appropriate “Select” button on the
Alignment screen to make the following
adjustments:
a)
Remove the SST-442 antenna from the
radio.
5)
Transmitter frequency error should be less than
+/- 500 Hz.
b)
Plug the SST-SRVBD into the 2.5 mm and
3.5 mm jacks on top of the radio.
6)
c)
Screw the SST-SRVBD antenna nut fully
into the SST-442 antenna connector.
If frequency adjustment is required, press the left
arrow on the tuning bar to lower the frequency or
the right arrow to raise the frequency.
7)
d)
Set the jumper on the SST-SRVBD
assembly to the “UHF” position.
Press the “Save” button to store the new
alignment setting or “Cancel” to leave setting
unchanged.
e)
Connect the serial programming cable from
the PC computer (with the RITRON PC
programming kit software installed) to the
SST-SRVBD test assembly
3)
Connect the FM communications test set to the
BNC connector on the SST-SRVBD test
assembly.
4)
Turn on the radio to place it in operating mode.
5)
From the PC Programmer on-screen menu,
select “Tune Radio” to display the Alignment
screen.
6)
Set the RF Communications Test set to the
Alignment Frequency indicated on the Alignment
screen.
21
ALIGNMENT PROCEDURE
SST-442
TRANSMITTER VOICE DEVIATION
MODULATION BALANCE
Transmitter modulation balance has been set at the
factory and should not require adjustment.
Transmitter voice deviation has been set at the
factory and should not require adjustment.
1)
Select “Mod Bal” from the PC Programmer
“Alignment” screen.
1)
Select “Voice” from the PC Programmer
“Alignment” screen.
2)
Set the RF communications test set to the
Alignment Frequency on the Alignment screen.
2)
Set the RF communications test set to the
transmit frequency on the screen.
3)
Press the “Tune” button on the Alignment screen
to activate the transmitter.
3)
4)
Check the de-modulated waveform for a 20 Hz
square wave.
Select “Voice Only - Wide Band“, “Voice Only Narrow Band”, “Voice & Tone – Wide Band”, or
“Voice & Tone – Narrow Band” by pressing the
desired option button.
5)
If adjustment of the modulation balance is
required, press the left arrow on the tuning bar to
flatten the top of the waveform or the right arrow
to reduce overshoot.
4)
Press the “Tune” button on the Alignment screen
to activate the transmitter.
5)
If adjustment of the voice deviation is required,
press the left arrow on the tuning bar to lower
deviation or the right arrow to raise deviation.
6)
Press the “Save” button to store the new
alignment setting or “Cancel” to leave setting
unchanged.
6)
Press the “Save” button to store the new
alignment setting or “Cancel” to leave setting
unchanged.
TRANSMITTER TONE DEVIATION
Transmitter tone deviation has been set at the factory
and should not require adjustment.
1)
Select “Tone” from the PC Programmer
“Alignment” screen.
2)
Set the RF communications test set to the
transmit frequency on the screen.
3)
Select either “Wide Band” or “Narrow Band” by
pressing the desired option button.
4)
Press the “Tune” button on the Alignment screen
to activate the transmitter.
5)
If adjustment of the tone deviation is required,
press the left arrow on the tuning bar to lower
deviation or the right arrow to raise deviation.
6)
Press the “Save” button to store the new
alignment setting or “Cancel” to leave setting
unchanged.
RECEIVER SENSITIVITY AND SQUELCH
The SST-442 receiver is factory tuned for a frequency
range of 460 - 470 MHz. The SST-442 receiver is
configured from the factory for Wide Band operation,
with a Narrow Band Model available as an option.
The SST-442 receiver bandwidth is configured on a
per radio basis, it cannot be switched on a per
channel basis.
The receiver may be tuned to any 10 MHz frequency
band between 450-470 MHz.
1)
Program the radio to a receive frequency in the
middle of the desired 10 MHz band.
2)
Set the RF communications test set generator to
a frequency exactly 87.3 MHz below the
programmed receive frequency at a RF level of
approximately –40 dB. Modulate the RF signal
with a 1 KHz tone at 3 KHz deviation for wide
band, 1.5 KHz deviation for low band.
3)
Connect an 8-Ohm speaker to the 3.5mm audio
jack on the SST-SRVBD test assembly.
4)
Adjust L101 for the minimum received signal at
this image frequency.
5)
Set the RF Communications Test Set’s generator
to the programmed receive frequency at a RF
level of –120 dB. Modulate the RF signal with a 1
KHz tone at 3 KHz deviation for wide band, 1.5
KHz deviation for low band.
6)
Adjust L103 and L104 for the best receiver
SINAD as measured across the 8-Ohm speaker.
7)
Check receiver sensitivity at the lowest and
highest operating frequencies and make slight
adjustment to L103 and L104 to balance
between the two, if necessary.
22
ALIGNMENT PROCEDURE
SST-442
SYNTHESIZER
RECEIVER NOISE SQUELCH
The noise squelch sensitivity is set at the factory for a
12dB SINAD signal. Using the PC Programmer,
squelch sensitivity can be adjusted on a per channel
basis by adjusting the “Squelch Tightener” number to
between 0-7. The higher number will require a
stronger received signal to open squelch.
1)
Select “Channel” from the PC Programmer “Edit”
menu on the main screen.
2)
Select the channel to be set and press “Edit”
button.
3)
Set the RF communications test set to the
transmit frequency on the screen.
4)
Enter a Squelch Tightener number between 0-7.
5)
Press the “OK” button on the Channel Edit
screen to return to the Channel List screen.
6)
Select any other channels to be set.
7)
Press the “OK” button on the Channel List screen
to return to the Main screen.
8)
The synthesizer is preset at the factory for operation
between 460 and 470 MHz. There is no manual
adjustment to center the control voltage, with all
adjustment performed by the factory selection of fixed
capacitor C413. Do not attempt to adjust the
synthesizer control unless a key component in the
synthesizer has been replaced. Key components do
not include the Y302 reference frequency TCVCXO or
IC401 synthesizer IC. Synthesizer alignment errors
cause poor operation at temperature extremes.
Should adjustment of the VCO control voltage be
necessary, the radio must first be disassembled and
powered up at 7.5 VDC. The following procedure
defines testing of the VCO control voltage:
1)
Select the channel that has the lowest receive
frequency.
2)
Connect a VTVM, DVM or oscilloscope to Test
Point 1 and measure the VCO control voltage.
This voltage should be no less than 1.5 VDC.
3)
Select the channel that has the highest receive
frequency and measure Test Point 1. The
control voltage should be no higher than 4.5
VDC.
4)
a)
If adjustment of the VCO control voltage is
required, remove the synthesizer shield top.
b)
Replace C413 with a capacitor value that
allows VCO control voltages between 1.5
and 4.5 VDC for the operating frequencies
desired. Decreasing the value of C413 will
raise the operating frequency of the VCO
while increasing the value will lower the VCO
frequency.
c)
Replace the top of the synthesizer shield.
Select “Program Radio” from the PC
Programmer “Radio” menu to save all setting
changes.
23
VOLTAGE CHART
SST-442
Measurement Conditions
REF
Supply voltage at 7.5 VDC, radio in operating mode,
volume control at minimum, power strobe enabled,
transmitter set for full power.
CR402
IMPORTANT: Because the SST-442 portable is
constructed with grounding sub-planes, use a system
ground in the same proximity as the circuit being
measured. All readings indicated as GND are true
system ground.
KEY: All measurements are in VDC unless indicated
otherwise.
NC
GND =
No connection
Ground
Voltage is strobed in
Power Saver mode
See note in right
column
→
REF
PIN
TX
RX
SB
TX/RX switching
CR102
GND GND GND
GND GND GND
0.0 0.0
Voltage clamp
CR103
GND GND GND
0.0
→
0.0 < 0.5 *
Noise detection
→ amplified receiver
noise
CR201
CR301
CR302
7.5
2.2
7.5
4.8
7.5
4.8
Reverse voltage
protection
CR303
6.8
4.2
6.1
6.8
4.2
6.1
6.8
4.2
6.1
Turn-on detection
CR304
2.0
2.2
2.4
4.7
4.7
5.0
4.7
4.7
5.0
PTT switching
CR305
CR306
2.4
NC
2.4
2.4
NC
2.4
2.4
NC
2.4
Voltage clamp
CR307
7.5
0.0
7.5
→
7.5
Reverse volt protection
→ RX audio amp out
CR401
5.0
4.8
NC
5.0
4.8
NC
NC
Biasing
1.4
NC
0.7
0.0
NC
0.0
0.0
NC
0.0
7.5 7.5 7.5
GND GND GND
GND GND GND
5.0 5.0 5.0
0.0 0.0 0.0
SB
DESCRIPTION
CR403
GND GND GND
NC NC NC
2.4 2.4
CR404
0.8
NC
0.0
0.0
NC
4.8
NC
TX/RX VCO switching
IC101
10
11
12
13
14
15
16
0.0
NC
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
NC
NC
GND
0.0
4.7
NC
3.8
4.7
3.8
3.8
3.8
4.7
2.0
0.6
2.4
0.0
NC
NC
GND
1.7
NC
NC
NC
GND
RX FM-IF subsystem
IC301
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
5.0
0.0
5.0
0.0
0.0
0.0
0.0
0.0
→
0.0
5.0
5.0
5.0
GND
5.0
4.2
5.0
2.4
0.0
5.0
→
0.0
0.0
NC
0.0
NC
→
5.0
5.0
5.0
0.0
0.0
0.0
0.0
0.0
0.0
→
0.0
0.0
5.0
5.0
GND
5.0
4.2
5.0
2.4
0.5
5.0
2.4
5.0
0.0
NC
0.0
NC
→
5.0
5.0
5.0
0.0
0.0
0.0
0.0
0.0
0.0
→
0.0
5.0
GND
5.0
4.2
5.0
5.0
0.0
0.0
NC
0.0
NC
→
5.0
Microcontroller
GND
GND
GND
GND
0.0
0.0
GND
5.0
GND
GND
GND
GND
0.0
0.0
GND
5.0
GND
GND
GND
GND
0.0
0.0
GND
5.0
DESCRIPTION
0.7 0.0 0.0
NC NC NC
GND GND GND
RX
GND GND GND
NC NC NC
→
→
SOT-23
TX
CR101
PIN
TX/RX switching
Over voltage protection
Voltage clamp
IC302
VCO tuning
→ 1.5 – 4.5 VDC
VCO tuning voltage
VCO modulation
→ 0.0 V on Channel 1
else 5.0 VDC
→ 0-5 VDC tone
encode waveform
→ 3.6 MHz clock signal
EEPROM
24
VOLTAGE CHART
REF
IC303
IC304
IC305
IC306
IC307
PIN
TX
10
11
12
13
14
2.4
2.4
2.4
5.0
2.4
2.4
2.4
2.4
2.4
2.4
GND
2.4
2.4
2.4
10
11
12
13
14
15
16
RX
SST-442
SB
DESCRIPTION
REF
2.4
2.4
2.4
5.0
2.4
2.4
2.4
2.4
2.4
2.4
GND GND
2.4
2.4
2.4
Audio processing
IC308
2.4
2.4
GND
5.0
2.4
2.4
5.0
3.2
2.4
2.4
GND GND
5.0
2.4
2.4
5.0
3.2
Tone low pass filter
IC309
7.5
GND
7.5
NC
5.0
7.5
GND
7.5
NC
5.0
7.5
GND
7.5
NC
5.0
+5 VDC voltage
regulator
0.0
2.4
2.4
2.4
0.0
GND
GND
GND
5.0
5.0
5.0
2.4
NC
0.0
0.0
5.0
0.0
2.4
2.4
2.4
2.5
GND
GND
GND
0.0
0.0
0.0
2.4
NC
2.4
2.4
5.0
Audio signal switching
IC401
2.4
2.4
2.4
GND
2.4
2.4
2.4
5.0
2.4
2.4
2.4
GND GND
2.4
2.4
2.4
5.0
Audio processing
→
→
5.0 5.0
NC NC
NC NC
5.0 5.0
→
→
GND GND
2.2 2.2
NC NC
2.4 2.4
2.4 2.4
5.0 5.0
NC NC
5.0 5.0
0.0 0.0
NC NC
5.0 5.0
5.0 5.0
0.0 0.0
2.2 → 2.2 →
→
NC
NC
5.0
GND
NC
NC
5.0
NC
5.0
→ 3.6 MHz clock signal
Frequency synthesizer
10
11
12
13
14
15
16
17
18
19
20
10
11
12
13
14
15
16
17
18
19
20
2.0
NC
GND
0.0
2.4
2.4
2.4
0.0
5.0
GND
NC
0.0
2.4
2.4
2.4
2.4
2.4
NC
5.0
5.0
2.0
NC
GND
2.5
2.4
2.4
2.4
0.0
5.0
GND
NC
0.0
2.4
2.4
2.4
2.4
2.4
NC
5.0
5.0
NC
GND
GND
NC
NC
Audio signal level
control
NC
0.0
GND
GND
0.0
0.0
0.0
NC
NC
0.0
GND
GND
3.7
7.5
3.7
NC
NC
0.0
GND
GND
0.0
0.0
0.0
NC
Audio amplifier
GND
GND
GND
0.0
0.0
0.0
NC
5.0
PIN
TX
5.0
5.0
0.0
RX
4.3
5.0
4.7
SB
DESCRIPTION
→ 1.5 – 4.5 VDC VCO
tuning voltage
→ 14.4 MHz reference
Q 101
Q 102
Q 103
Q 104
0.0 0.7
GND GND GND
0.0 1.2
RX IF amplifier
Q 105
0.0 0.7
GND GND GND
0.0 4.6
RX 2 LO
multiplier/amp
Q 201
6.8
7.5
7.0
7.5
7.5
0.0
7.5
7.5
0.0
TX +V switching
Q 202
5.0
4.3
6.8
0.0
0.0
7.5
0.0
0.0
7.5
TX +V switching
Q 203
0.0 0.7
GND GND GND
0.0 3.0
0.0
0.0
0.0
4.7
0.0
1.8
0.7 0.0 0.0
GND GND GND
5.6 0.0 0.0
RX +V switching
RX RF amplifier
RX mixer
nd
TX RF amplifier
25
VOLTAGE CHART
REF
PIN
TX
RX
SST-442
SB
DESCRIPTION
Q 204
0.2 0.0 0.0
GND GND GND
7.0 0.0 0.0
TX RF driver amplifier
Q 205
GND GND GND
0.0 0.0 0.0
7.5 7.5 7.5
TX RF Final amplifier
Q 301
5.0 0.0 0.0
GND GND GND
0.0 5.0 5.0
PTT detection
Q 302
4.3
5.0
5.0
5.0
5.0
0.0
5.0
5.0
0.0
PTT detection
Q 303
5.0
4.3
6.8
5.0
4.3
6.8
5.0
4.3
6.8
Battery +V switching
Q 304
6.8
7.5
7.5
6.8
7.5
7.5
6.8
7.5
7.5
Battery +V switching
Q 306
4.3
5.0
5.0
4.3
5.0
5.0
5.0
5.0
+5V switching
Q 307
0.0
0.0
7.5
5.0
4.3
6.8
0.0
0.0
7.5
Audio amplifier enable
Q 308
7.5
7.5
0.0
6.8
7.5
7.5
7.5
7.5
0.0
Audio amplifier +V
switching
Q 401
0.7 0.7
GND GND GND
2.9 2.9
VCO buffer amplifier
Q 402
0.7 0.7
GND GND GND
2.8 2.8
VCO buffer amplifier
Q 403
2.3
1.6
4.3
2.3
1.6
4.3
VCO oscillator
Q 404
4.7
4.3
5.0
4.7
4.3
5.0
VCO voltage
de-coupling
Q 405
0.0
4.3
4.2
4.3
4.3
0.0
TX/RX VCO switching
Q 406
0.0 4.3
GND GND GND
4.3 0.0
TX/RX VCO switching
26
SCHEMATIC REFERENCE PARTS LIST
SST-442
NOTE: This parts list reflects the most current component values. If a component value given in the schematic
differs from this list, the parts list should be considered the most current.
Last Update:
Ref
Ritron PN
May 11, 2001
Description
Theta
1065
949
791
649
1016
920
734
675
637
557
516
382
476
275
380
276
199
160
485
407
138
451
450
319
350
441
61
217
392
571
38
64
61
39
171
1524
871
1004
1466
1517
1572
1571
1375
977
1277
1278
977
1682
1682
1614
1439
1035
953
1682
774
275
199
3824
3929
4059
3620
3682
3790
3620
3519
3994
3993
4099
4099
3993
4059
3786
3382
3598
3491
3367
3548
947
1669
946
904
1364
1542
2203
2114
1802
904
1263
1156
2123
1635
1533
2585
3384
3248
2357
267
239
3084
2883
3530
3493
3267
3481
3881
3881
4120
4093
4136
4136
3881
817
522
647
270
180
90
180
270
180
180
90
270
270
180
180
270
90
180
180
90
270
90
90
90
270
90
270
90
180
270
90
270
270
270
90
180
270
90
180
90
180
180
90
90
90
180
180
270
180
Loc
CAPACITORS
C101
C102
C103
C104
C105
C106
C107
C108
C109
C110
C111
C112
C113
C114
C115
C116
C117
C118
C119
C120
C121
C122
C123
C124
C125
C126
C127
C128
C129
C130
C131
C132
C133
C134
C135
C201
C202
C203
C204
C205
C206
C207
C208
C209
C210
C211
C212
C213
C214
C215
C216
C217
C218
C219
C301
C302
C303
151103A3
151104A7
15110120
15180101
151106A8
15110180
15181102
15181102
151106A8
151103A3
151103A3
151103A3
15110100
151108A2
15110150
15182103
15110150
15110470
15181472
151108A2
15181102
152B6106
15181102
15181102
15119104
15119104
15119104
15119104
15119104
15182103
15110330
15110330
15119104
15182103
15110220
15180330
15181102
15180101
151105A6
15119104
15110150
151108A2
15180101
15180101
15181102
15110150
15180330
151106A8
15110120
151108A2
151101A8
15110101
151104A7
15181102
15181102
152B4226
3.3pf NPO 0805 CHIP CAPACITOR
4.7PF 0805 50V CHIP CAP.
12PF NPO 0805 50V CHIP CAP
100pF CAPACITOR, CHIP, 0402, COG, 5%
6.8PF NPO 0805 50V CHIP
18PF NPO 0805 50V CHIP
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
6.8PF NPO 0805 50V CHIP
3.3pf NPO 0805 CHIP CAPACITOR
3.3pf NPO 0805 CHIP CAPACITOR
3.3pf NPO 0805 CHIP CAPACITOR
10PF NPO 0805 50V CHIP CAP
8.2PF NPO 0805 50V CHIP
15PF 0805 NPO 50V CHIP CAP
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
15PF 0805 NPO 50V CHIP CAP
47PF NPO 0805 50V CHIP
.0047uF CAPACITOR, CHIP, 0402, X7R,5/10%
8.2PF NPO 0805 50V CHIP
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
10uF 10V 3.4 X 2.8 CHIP TANTALUM
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.1uF X7R 0805 25V CERAMIC CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
33PF NPO 0805 50V CHIP
33PF NPO 0805 50V CHIP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
22PF NPO 0805 50V CHIP CAP
33pF CAPACITOR, CHIP, 0402, C0G, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
5.6PF NPO 0805 50V CHIP CAPACITOR
.1uF X7R 0805 25V CERAMIC CHIP CAP
15PF 0805 NPO 50V CHIP CAP
8.2PF NPO 0805 50V CHIP
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
15PF 0805 NPO 50V CHIP CAP
33pF CAPACITOR, CHIP, 0402, C0G, 5%
6.8PF NPO 0805 50V CHIP
12PF NPO 0805 50V CHIP CAP
8.2PF NPO 0805 50V CHIP
Factory Select
1.8PF 0805 50V CHIP CAP.
100PF NPO 0805 50V CHIP CAP
4.7PF 0805 50V CHIP CAP.
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
22uF 6.3V 3.4 X 2.8 CHIP TANTALUM CAP
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Top
Bottom
Bottom
Top
Top
Top
Top
Top
Top
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Top
Bottom
Top
Top
27
SCHEMATIC REFERENCE PARTS LIST
Ref
Ritron PN
Description
C304
C305
C306
C307
C309
C310
C311
C312
C313
C314
C315
C316
C317
C318
C319
C320
C321
C322
C323
C324
C325
C326
C327
C328
C329
C330
C331
C332
C333
C334
C335
C336
C337
C338
C339
C340
C341
C342
C343
C344
C345
C346
C347
C348
C349
C350
C351
C352
C353
C354
C355
C356
C357
C358
C359
C360
C361
C362
C363
C364
C365
C366
C367
C368
15181102
15180101
15180101
15182103
15182103
15119104
15181102
15182103
15181102
15181102
15181102
15182103
15181102
15181102
15181102
15181102
15181102
15180101
15181102
15119104
15180101
15180101
15181102
15181102
15181102
15181102
15181102
15181102
152A6475
15119104
15180101
15181332
152B6106
15180101
15119104
15111333
15182103
15110821
15111102
15181472
15181472
152A8105
15180180
15119473
15111333
15180101
15181222
15180100
15182103
15181221
15181102
15181102
15181102
15181102
15180100
15181102
15180101
15119104
152B6106
152B6106
01503212
15119104
15119104
15181102
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
.1uF X7R 0805 25V CERAMIC CHIP CAP
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.1uF X7R 0805 25V CERAMIC CHIP CAP
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
4.7UF 10V A-SIZE TANTALUM CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
100pF CAPACITOR, CHIP, 0402, COG, 5%
.0033uF CAPACITOR, CHIP, 0402, X7R,5/10%
10uF 10V 3.4 X 2.8 CHIP TANTALUM
100pF CAPACITOR, CHIP, 0402, COG, 5%
.1uF X7R 0805 25V CERAMIC CHIP CAP
.033MFD X7R 0805 50V CHIP CAP
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
820PF NPO 0805 50V CHIP CAP
.001MF X7R 0805 50V CHIP CAP
.0047uF CAPACITOR, CHIP, 0402, X7R,5/10%
.0047uF CAPACITOR, CHIP, 0402, X7R,5/10%
1MFD 16V ~3.2 X 1.6~ CHIP TANTALUM
18pF CAPACITOR, CHIP, 0402, COG, 5%
.047uF X7R 0805 25V CHIP CAPACITOR
.033MFD X7R 0805 50V CHIP CAP
100pF CAPACITOR, CHIP, 0402, COG, 5%
.0022uF CAPACITOR, CHIP, 0402, X7R,5/10%
10pF CAPACITOR, CHIP, 0402, COG, 5%
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
220pF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
10pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.1uF X7R 0805 25V CERAMIC CHIP CAP
10uF 10V 3.4 X 2.8 CHIP TANTALUM
10uF 10V 3.4 X 2.8 CHIP TANTALUM
220MF 10V ELT CAPACITOR, 5mm HEIGHT
.1uF X7R 0805 25V CERAMIC CHIP CAP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
SST-442
Theta
Loc
1261
1027
613
20
582
1106
1229
544
169
1280
1280
826
704
826
704
1280
1280
1280
1280
969
1280
1280
1280
655
634
704
704
704
493
82
366
454
724
254
245
331
585
638
637
179
264
614
286
474
82
493
35
436
594
379
250
188
125
585
450
464
459
981
1231
1075
1493
1509
1357
220
4590
405
402
4621
1865
328
2967
4622
3033
2589
2271
2291
2321
2371
2360
2403
2496
2311
2771
2221
2672
2628
2350
2408
2471
2612
2690
2729
2701
2765
2880
3156
3558
3144
2964
2665
2328
2982
3063
2432
2432
2232
2500
2595
2657
3156
2641
3228
3131
2436
2413
2434
2415
2498
2573
2283
2139
752
427
455
5509
720
814
2695
90
270
270
90
90
270
270
180
180
180
180
180
180
180
180
180
180
180
270
180
180
270
90
270
90
270
270
270
180
180
90
90
90
90
270
90
180
90
180
90
180
90
270
270
90
270
90
0.399
180
90
270
Bottom
Top
Top
Top
Bottom
Top
Bottom
Top
Top
Bottom
Bottom
Top
Bottom
Top
Bottom
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Bottom
Bottom
Top
Top
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
Top
Top
Bottom
Bottom
Top
Top
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Top
Bottom
Bottom
Top
Bottom
Top
Bottom
Bottom
Bottom
28
SCHEMATIC REFERENCE PARTS LIST
Ref
Ritron PN
Description
C369
C370
C371
C372
C373
C374
C401
C402
C403
C404
C405
C406
C407
C408
C409
C410
C411
C412
C413
C414
C415
C416
C417
C418
C419
C420
C421
C422
C423
C424
C425
C426
C427
C428
C429
C430
C431
C432
C433
C434
C435
15180101
15181102
15181102
15111103
15119104
15181102
15180101
151104A7
15181102
15181102
15180101
151101A5
151104A7
151104A7
15119104
151104A7
15180101
15181102
151102A7
152B6106
15181102
15180101
15180101
15180101
15181102
15181102
15180101
15110100
151101A0
151108A2
15180101
15111222
152AB334
15180101
15111333
15180101
15182103
15180101
15180101
15180101
15180101
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.01MF X7R 0805 50V CHIP
.1uF X7R 0805 25V CERAMIC CHIP CAP
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
4.7PF 0805 50V CHIP CAP.
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
1.5PF NPO 0805 50V CHIP
4.7PF 0805 50V CHIP CAP.
4.7PF 0805 50V CHIP CAP.
.1uF X7R 0805 25V CERAMIC CHIP CAP
4.7PF 0805 50V CHIP CAP.
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
2.7pf NPO 0805 CHIP CAPACITOR
10uF 10V 3.4 X 2.8 CHIP TANTALUM
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
.001uF CAPACITOR, CHIP, 0402, X7R, 5/10%
100pF CAPACITOR, CHIP, 0402, COG, 5%
10PF NPO 0805 50V CHIP CAP
1.0PF NPO 0805 50V CHIP
8.2PF NPO 0805 50V CHIP
100pF CAPACITOR, CHIP, 0402, COG, 5%
.0022uF X7R 0805 50V CHIP CAPACITOR
.33MF 35V ~3.2X1.6~ CHIP TANTALUM
100pF CAPACITOR, CHIP, 0402, COG, 5%
.033MFD X7R 0805 50V CHIP CAP
100pF CAPACITOR, CHIP, 0402, COG, 5%
.01uF CAPACITOR, CHIP, 0402,Z5U,5/10/20
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
100pF CAPACITOR, CHIP, 0402, COG, 5%
SST-442
Theta
Loc
664
297
704
444
364
566
1566
1640
1680
1066
1353
1182
1463
1572
980
1355
1262
1047
1462
722
1535
1731
1538
677
678
678
1053
1119
1256
1187
1069
832
812
855
1029
971
687
766
932
1101
687
2454
2861
2651
719
2322
2583
1966
194
1828
1850
2013
1785
1604
1634
1766
158
130
1788
1441
1625
969
1114
1356
1121
1213
1260
1576
1512
1400
1252
937
922
1015
1473
1015
1460
1393
1100
1460
1264
1355
90
180
270
270
90
270
90
90
180
180
270
270
90
270
270
90
270
270
270
90
180
180
180
180
180
270
90
180
270
270
180
180
90
180
Top
Top
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
48D100A2
48E1005G
48A1005C
48D100A2
48B61012
48AA01SA
48A1005B
48A100A3
48A1005C
48A1005C
48AA01SA
48A1005C
48C1004E
48C1004G
48A1004D
MA4CP101A PIN DIODE, SOT-23
1178
MMBD-352LT1 SCHOTTKY DIODE SOT23
906
MMBD7000, DUAL DIODES IN SERIES, SOT-23
366
MA4CP101A PIN DIODE, SOT-23
1302
1N4742A ZENER DIODE, 12V 1W DL-41 MELF
991
DIODE, 1A, 50V, SMT, D0214AC CASE
1154
MMBD6100, DUAL DIODES, COM CATHODE, SOT2 363
MMBD2835, DUAL DIODES, COM ANODE, SOT-23
65
MMBD7000, DUAL DIODES IN SERIES, SOT-23
615
MMBD7000, DUAL DIODES IN SERIES, SOT-23
462
DIODE, 1A, 50V, SMT, D0214AC CASE
1290
MMBD7000, DUAL DIODES IN SERIES, SOT-23
695
MMBV-105G DIODE VVC, SOT-23
1155
MMBV-2101L DIODE VVC SOT-23
1119
MMBV3401 PIN/UHF DIODE SOT-23
1552
3820
3682
2119
3991
604
630
431
4089
2821
2949
630
1808
1115
1400
1239
90
270
90
90
90
90
90
90
180
180
270
Top
Top
Bottom
Top
Top
Top
Top
Top
Bottom
Bottom
Top
Top
Top
Top
Top
06000040
WIRE; #40AWG TINNED BUS (INCHES)
603
270
Bottom
DIODES
CR101
CR102
CR103
CR201
CR301
CR302
CR303
CR304
CR305
CR306
CR307
CR401
CR402
CR403
CR404
FUSE
F301
754
29
SCHEMATIC REFERENCE PARTS LIST
Ref
Ritron PN
Description
SST-442
Theta
Loc
INTEGRATED CIRCUITS
IC101
IC301
IC302
IC303
IC304
IC305
IC306
IC307
IC308
IC309
IC401
31030003
314G0306
31210005
310K0004
311K0003
310K0003
310K0001
31010004
310K0002
310E0002
313K0005
MC3371D SUBSYSTEM IC, SO-16
314
MCU, 28 PIN, SOIC, SST/JMX 4 SERIES v06
992
EEPROM, 512X8, 24C04
989
LMV324MT RAIL TO RAIL QUAD OP AMP
474
SWITCH,ANALOG,TRIPLE SPDT,4053,TSSOP-16
226
LMV358MM DUAL OP AMP, GP LV R/R TSSOP
404
DS1806E 6 PROG POTS 10K OHM 20-PIN TSSOP 242
LM386MX-1 AUDIO AMP SO-8
1331
MAX7410 5TH ORDER SW CAP BUTTERWORTH LPF407
REGULATOR,LDO,LP2980,5V,W ENABLE,SOT-25 162
SYNTHESIZER, MC145193, TSSOP
891
1158
2546
2501
2442
2683
3120
2185
583
2946
504
1265
270
180
180
90
180
Bottom
Bottom
Top
Top
Top
Top
Top
Bottom
Top
Top
Top
02100001
02100053
2.5MM PC-MT JACK; ANT-CHGR
3.5MM STEREO JACK; PANEL MOUNT
1178
1560
4668
4646
1.5T SW COIL W/5MM SHIELD & ALUM CORE
CHIP INDUCTOR .15uhy
1.5T SW COIL W/5MM SHIELD & ALUM CORE
1.5T SW COIL W/5MM SHIELD & ALUM CORE
3T AIRCOIL, SMT, 8.0nH, .120 X .145
CHIP INDUCTOR 1.0uhy
1T AIRCOIL, SMT 2.5nH, .120 X .145
CHIP INDUCTOR .68uhy
4.5T AIRCOIL #24AWG .0625ID RHH SMT
4.5T AIRCOIL #24AWG .0625"ID RHH SMT
2T AIRCOIL SMT 5.0nH .120 X .145
CHIP INDUCTOR 10uhy
8.5T AIRCOIL #24AWG .0625"ID RHH SMT
2T AIRCOIL SMT 5.0nH .120 X .145
4.5T AIRCOIL #24AWG .0625"ID RHH SMT
4.5T AIRCOIL #24AWG .0625"ID RHH SMT
CHIP INDUCTOR 1.0uhy
5.5T AIRCOIL #24AWG .0625"ID RHH SMT
2T AIRCOIL SMT 5.0nH .120 X .145
8T AIRCOIL, SMT, 8.80 nH, .159 X .056
9.5T AIRCOIL #24AWG .0625"ID RHH SMT
INDUCTOR, CHIP 82nH
CHIP INDUCTOR 0.1uhy
CHIP INDUCTOR 0.1uhy
721
629
484
204
332
280
480
51
1399
1478
1591
1386
1143
1737
1695
1479
1335
1093
932
1376
1352
1548
1205
753
4291
3722
4291
4292
3901
3474
3492
1658
2474
2880
3250
3262
3523
3765
4001
3945
3804
3979
4343
1418
118
109
966
1485
90
270
270
270
180
180
180
180
90
90
180
90
180
90
90
270
270
270
Top
Top
Top
Top
Top
Top
Top
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Bottom
896
754
4550
737
90
675
734
340
270
38
908
766
1453
1699
1469
3405
3828
3639
3548
1374
3268
3268
2248
291
3543
270
270
180
90
270
270
50
JACKS
J301
J303
Top
Top
INDUCTORS
L101
L102
L103
L104
L105
L106
L107
L108
L201
L203
L204
L205
L206
L207
L208
L209
L210
L211
L212
L401
L402
L403
L404
L405
01850201
18110151
01850201
01850201
18433103
18110102
18433101
18110681
18414104
18414104
18433102
18110103
18414108
18433102
18414104
18414104
18110102
18414105
18433102
18433208
18414109
18110820
18110101
18110101
MICROPHONE
M301
05500037
MICROPHONE; ELECTRET, MINIATURE
CONNECTORS
P201
P302
25500700
21310021
CONTACT, PCB MNT, ANTENNA,SST
HEADER, 2 PIN SIDE ENTRY SHROUDED
Top
Top
TRANSISTORS
Q101
Q102
Q103
Q104
Q105
Q201
Q202
Q203
Q204
Q205
4801002A
482100V0
4841006U
4821003B
4821003B
480100DH
4801001Q
482100V0
48280001
04801013
MMBT3906 PNP, SOT23
TRANSISTOR, NPN, UHF, SOT-23, PBR-941
MMBFJ309LT1, N-CHAN, RF, SOT23
MMBT918LT1 VHF SOT23 (3B)
MMBT918LT1 VHF SOT23 (3B)
BCW68GLT1 .8AMP PNP SOT-23
MMBT5088, NPN, SOT-23
TRANSISTOR, NPN, UHF, SOT-23, PBR-941
BFG135 WB SOT-223 1W TRANSISTOR
MRF-630 3 W UHF AMP TRAN. NPN
Top
Top
Top
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
30
SCHEMATIC REFERENCE PARTS LIST
Ref
Ritron PN
Description
Q301
Q302
Q303
Q304
Q306
Q307
Q308
Q401
Q402
Q403
Q404
Q405
Q406
48010R02
4801002A
4801001Q
480100DH
480100DH
4801001Q
480100DH
482100V0
482100V0
482100V0
4801001Q
4801006A
48010R02
SST-442
Theta
Loc
MUN2211T1, NPN, INT 10K/10K BIAS, "8A",
MMBT3906 PNP, SOT23
MMBT5088, NPN, SOT-23
BCW68GLT1 .8AMP PNP SOT-23
BCW68GLT1 .8AMP PNP SOT-23
MMBT5088, NPN, SOT-23
BCW68GLT1 .8AMP PNP SOT-23
TRANSISTOR, NPN, UHF, SOT-23, PBR-941
TRANSISTOR, NPN, UHF, SOT-23, PBR-941
TRANSISTOR, NPN, UHF, SOT-23, PBR-941
MMBT5088, NPN, SOT-23
MUN2111T1, PNP, INT 10K/10K BIAS, SC-59
MUN2211T1, NPN, INT 10K/10K BIAS, "8A",
1133
1094
583
445
1222
964
1162
1470
1289
1460
837
1634
1691
2987
3124
519
668
2259
615
669
1919
1920
1714
1766
1376
1234
90
90
90
270
270
270
270
270
Bottom
Bottom
Top
Top
Top
Bottom
Bottom
Top
Top
Top
Top
Top
Top
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
3.9K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
560 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1.5K OHM RESISTOR, CHIP, 0402, 1/16W,5%
1.5K OHM RESISTOR, CHIP, 0402, 1/16W,5%
22K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
100 OHM RESISTOR, CHIP, 0402,1/16W,5%
150K OHM RESISTOR, CHIP, 0402, 1/16W,5%
1.2K OHM RESISTOR, CHIP, 0402, 1/16W,5%
220K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
12K OHM RESISTOR, CHIP, 0402, 1/16W,5%
1.5K OHM RESISTOR, CHIP, 0402, 1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
39K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
680 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
470 OHM RESISTOR, CHIP, 0402, 1/6W, 5%
180 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1.5K OHM RESISTOR, CHIP, 0402, 1/16W,5%
47 OHM 0805 CHIP RES.
2.2K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
270 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
220 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
180 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
470 OHM 0805 CHIP RES.
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
4.7K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
579
734
773
829
714
475
388
251
167
411
529
349
489
551
153
153
117
49
49
78
790
669
897
1357
1318
1438
1605
1720
1277
1217
879
536
475
316
623
409
621
995
1086
1257
704
504
704
1206
1260
709
761
800
704
3344
3581
3709
3810
3519
3610
3484
3450
3450
946
904
966
946
966
2174
2089
1676
1509
1470
1635
3384
3248
3151
2228
2228
2678
2718
271
3581
3726
4148
686
479
546
639
547
1865
3143
334
2891
2191
4622
2230
2376
2375
2834
2506
2506
2520
90
180
270
270
270
270
180
180
180
270
270
180
90
270
90
90
180
90
90
270
90
90
90
270
180
180
270
180
90
90
270
90
270
270
90
90
5180
270
270
270
270
90
90
90
180
Top
Top
Top
Top
Top
Top
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Top
Bottom
Bottom
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Bottom
Bottom
Top
Bottom
Bottom
Top
Bottom
Top
Top
Bottom
Top
Top
Bottom
RESISTORS
R101
R102
R103
R104
R105
R106
R107
R108
R109
R110
R111
R112
R113
R114
R115
R116
R117
R118
R119
R120
R201
R202
R203
R205
R206
R207
R208
R209
R210
R211
R212
R301
R302
R303
R304
R305
R306
R307
R308
R309
R310
R311
R312
R313
R314
R315
R316
R317
R318
47180103
47180103
47180102
47180392
47180561
47180152
47180152
47180223
47180101
47180154
47180122
47180224
47180123
47180152
47180104
47180103
47180393
47180103
47180102
47180681
47180103
47180471
47180181
47180103
47180152
47100470
47180222
47180271
47180221
47180181
47180102
47180103
47100471
47180104
47180102
47180104
47180103
47180103
47180103
47180103
47180104
47180104
47180103
47180104
47180472
47180102
47180103
47180103
47180104
31
SCHEMATIC REFERENCE PARTS LIST
Ref
Ritron PN
Description
R319
R320
R321
R322
R323
R324
R325
R326
R327
R328
R329
R330
R331
R332
R333
R334
R335
R336
R337
R338
R339
R340
R341
R342
R343
R344
R345
R346
R348
R349
R350
R352
R353
R354
R355
R356
R357
R358
R359
R362
R401
R402
R403
R404
R405
R406
R407
R408
R409
R410
R411
R412
R413
R414
R415
R416
R417
R418
R419
R420
R421
R422
R423
47180471
47180471
47180103
47180393
47180823
47180224
47180104
47180183
47180183
47180103
47180153
47180100
47180104
47180154
47180473
47180273
47180102
47180104
47180103
47180224
47180394
47180104
47180104
47180184
47180564
47180104
47180104
47180102
47180473
47180823
47180564
47100225
47180103
47180102
47180103
47180273
47180102
47180103
47180100
47180100
47180221
47180101
47180272
47180102
47180101
47180272
47180470
47180470
47180271
47180153
47180153
47180102
47180472
47180103
47180102
47180104
47180102
47180473
47180822
47180103
47180392
47180100
47180474
470 OHM RESISTOR, CHIP, 0402, 1/6W, 5%
470 OHM RESISTOR, CHIP, 0402, 1/6W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
39K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
82K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
220K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
18K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
18K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
15K OHM RESISTOR, CHIP, 0402, 1/16W,5%
10 OHM RESISTOR, CHIP,0402, 1/16W 5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
150K OHM RESISTOR, CHIP, 0402, 1/16W,5%
47K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
27K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
220K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
390K OHM RESISTOR, CHIP, 0402, 1/6W, 5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
180K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
560K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
47K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
82K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
560K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
2.2M 0805 CHIP RESISTOR
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
27K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
10 OHM RESISTOR, CHIP,0402, 1/16W 5%
10 OHM RESISTOR, CHIP,0402, 1/16W 5%
220 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
100 OHM RESISTOR, CHIP, 0402,1/16W,5%
2.7K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
100 OHM RESISTOR, CHIP, 0402,1/16W,5%
2.7K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
47 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
47 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
270 OHM RESISTOR, CHIP, 0402, 1/16W, 5%
15K OHM RESISTOR, CHIP, 0402, 1/16W,5%
15K OHM RESISTOR, CHIP, 0402, 1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
4.7K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
100K OHM, RESISTOR, CHIP, 0402,1/16W,5%
1K OHM RESISTOR, CHIP,0402, 1/16W,5%
47K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
8.2K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10K OHM, RESISTOR, CHIP, 0402,1/16W,5%
3.9K OHM RESISTOR, CHIP, 0402, 1/16W, 5%
10 OHM RESISTOR, CHIP,0402, 1/16W 5%
470K OHM RESISTOR, 0402, 1/16W, 5%
SST-442
Theta
704
638
760
274
371
313
416
585
624
477
179
664
264
207
246
566
43
532
397
468
340
250
63
741
21
125
742
411
29
29
44
486
847
912
1181
1183
250
1601
507
1517
1640
1450
1452
1153
1193
1086
1067
1636
1266
1363
1271
677
1634
1641
1138
938
938
718
718
1101
894
850
2768
2917
2951
3069
3070
3070
3156
2413
2328
2791
2391
2369
2392
2501
2500
2588
2774
2774
3156
3228
2366
2436
2455
2395
3130
2428
2455
3092
2573
2146
2198
2406
2166
653
772
765
534
2374
741
2622
2006
1828
2013
1825
1900
1900
1788
1726
1655
162
1694
1827
1903
1531
1068
1576
937
1022
906
946
1303
1461
1100
180
180
270
270
270
90
270
90
270
180
90
90
90
90
270
270
270
90
270
90
270
270
180
180
270
180
180
90
270
180
270
180
90
270
180
180
270
270
270
180
90
5180
270
180
270
90
90
90
180
90
180
Loc
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Bottom
Top
Bottom
Bottom
Bottom
Bottom
Top
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
Top
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Bottom
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
Top
32
SCHEMATIC REFERENCE PARTS LIST
SST-442
SPEAKER
SP301
05500045
SPEAKER, 45MM, 1W, LOW PROFILE SST/RTX
Bottom
SWITCH SPST MOMENTARY MINI PC 260GM
SWITCH SPST MOMENTARY MINI PC 260GM
SWITCH, TACT LO PROFILE RT ANGLE 160gf
SWITCH, TACT LO PROFILE RT ANGLE 160gf
268
788
82
82
4587
4588
3097
3948
180
180
270
270
Top
Top
Top
Top
455KHZ IF TRANSFORMER (5MM)
128
1822
180
Top
23050003
TCVCXO, 14.400 MHz, 1.5 PPM, VC=30 PPM/V
146
837
90
Top
02301403
02301013
43.650 MHz Crystal Filter +/-6.0KHz UM-1
FILTER,CERAMIC,450KHz,+/-7.5KHz,6 POLE
44
249
3524
1614
90
90
Top
Top
SWITCHES
SW301
SW302
SW303
SW304
05100042
05100042
05100046
05100046
TRANSFORMER
T101
05600018
CRYSTAL
Y302
FILTERS
YF101
YF102
HARDWARE
1750270A
25602500
06001010
06001011
06001023
06001029
25105500
25603000
25603900
25605700
PCB, ML4 FR4 5UPM, .062 MIX, SST-442
CRYSTAL SUPPORT, RUBBER PAD, SMALL/UM-1
#24 AWG STRANDED WIRE; RED (INCHES)
#24 AWG STRANDED WIRE; BLACK INCHES
#28 AWG STRANDED WIRE;GREEN INCHES
#28 AWG STRANDED WIRE; BLUE INCHES
SHIELD, SST-PLUS SYNTHESIZER
FOAM, MOUNTING, SPEAKER,SST
SPACER, MIC FOAM, SST
MICROPHONE HOLDER, SST-PLUS
ANTENNA
AFS-450
ANTENNA UHF MOLDED, 450-470 REG LEN SST
MAIN CASE ASSEMBLY
13250000
13578000
13588000
25106400
25201500
25400600
25603300
25603400
25606200
25800500
25800600
02802026
02802027
28112401
28233G03
CASE W/INSERT, PLASTIC, SST BLACK
DOOR, BATTERY, PLASTIC, SST 2-PC
LATCH, BATTERY DOOR, PLASTIC SST 2-PC
BATTERY DOOR HINGE RETAINER
RETAINER, PLASTIC, PTT, SST
BUSHING, THREADED, PLATED, ANTENNA SS
GRILLE CLOTH, SPEAKER, SST
DUAL JACK PLUG, RUBBER,SST
HINGE, BATTERY DOOR, SST
ACTUATOR, RUBBER,PTT,SST
ACTUATOR, RUBBER, TACT, SST
NUT; KNURLED; M4PO.5;/2.5MM JACK
NUT; KNURLED; M6PO.5/3.5MM JACK
SCREW 4-40 X 1/4" PHFLST
KNURLED NUT, ANTENNA, JMX
CASE BOTTOM ASSEMBLY
13564000
2142D021
25400800
25400900
25604800
CASE, BOTTOM, PLASTIC, SST 2-PC
CONNECTOR, CABLE ASSEMBLY, 2-POS, SST+
SPRING CONTACT, BATTERY, SST W/O TABSC
CONTACT BATTERY SST-PLUS (POLARIZED)
SPACER, PCB, FOAM, SST 2-PC
BELT CLIP
25201600
2811B600
BELT CLIP, PLASTIC, SST BLACK
SCREW 6-32 X 1/4" PHTRST
33
SCHEMATIC REFERENCE PARTS LIST
Ritron PN
SST-442
Description
SST-442 MODELS ONLY
CASE LABELS
14220001
14222029
14290002
14200037
14200100
LABEL, CONTROLS, SST
LABEL, NAMEPLATE, SST
BLANK LABEL, .75" X .25" GLOSSY WHITE
LABEL SST/JMX MFG DATE CODE
LABEL, FCC SERIAL, SST-442
BATTERY PACK AND INSULATOR
BPS-6N-SC
14230088
25300600
25606000
25601600
BATTERY,RECHG,7.2V NiCd,BLUE ,SST
LABEL, BATTERY, BPS-6N-SC, SST
INSULATOR, BATTERY, FIBRE, SST
FOAM SUPPORT, BATTERY JMX SERIES
BATTERY SHIM; ASSEMBLY ~X~ SERIES
PACKING MATERIALS
14210004
14312006
14321002
14500025
14540006
LOW BATTERY NOTICE LABEL
SHIPPING CARTON, CARDBOARD,SST
FOAM INSERT, PACKING, SST/MINI
OWNER'S MANUAL, 14x/44x SERIES, JMX/SST
WARRANTY REGISTRATION CARD
JMX-442 MODELS ONLY
CASE LABELS
14220002
14222035
14290002
14200037
14200101
LABEL, CONTROLS, JMX
LABEL, NAMEPLATE, JMX
BLANK LABEL, .75" X .25" GLOSSY WHITE
LABEL SST/JMX MFG DATE CODE
LABEL, FCC SERIAL, JMX-442
BATTERY PACK AND INSULATOR
BPJS-6N
BC-A
14230088
25300600
25606000
25601600
BATTERY, YELLOW, RECHG,7.2V NiCd 700 mAH
BATTERY CHARGER, 120VAC-5.5VDC 100mA
LABEL, BATTERY, BPS-6N-SC, SST
INSULATOR, BATTERY, FIBRE, SST
FOAM SUPPORT, BATTERY JMX SERIES
BATTERY SHIM; ASSEMBLY ~X~ SERIES
PACKING MATERIALS
14210004
14313012
14352004
14500025
14540006
14610006
LOW BATTERY NOTICE LABEL
BOX, CHIPBOARD, SMALL, 4 COLOR, JMX
INSERT, CORREGATED CARDBOARD, JMX
OWNER'S MANUAL, 14x/44x SERIES, JMX/SST
WARRANTY REGISTRATION CARD
JOBCOM BROCHURE
34

---

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Create Date                     : 2001:04:18 17:01:12
Producer                        : Acrobat Distiller 4.0 for Windows
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Title                           : Microsoft Word - 442_man.doc
Modify Date                     : 2001:05:11 17:06:42-05:00
Page Count                      : 37
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