Shure orporated UC1B User Manual UC1 srv

Download:
Mirror Download [FCC.gov]
Document ID	47195
Application ID	d4/QfilsBSr3oc5POWPH+g==
Document Description	User Manual
Short Term Confidential	No
Permanent Confidential	No
Supercede	No
Document Type	User Manual
Display Format	Adobe Acrobat PDF - pdf
Filesize	104.04kB (1300452 bits)
Date Submitted	1999-07-12 00:00:00
Date Available	1999-11-10 00:00:00
Creation Date	1998-09-18 08:49:41
Producing Software	Acrobat Distiller Daemon 3.01 for HP-UX A.09.01 and later (HPPA)
Document Lastmod	1999-07-12 15:05:41
Document Title	UC1_srv
Document Creator	Interleaf, Inc.
Document Author:	campben

Service Manual
UC1 / UC1L Body-Pack
UHF Transmitter
Characteristics
General
The Shure UC1/UC1L Body-Pack Transmitter is microprocessorcontrolled, operating in the 774 – 862 MHz frequency range. The UC1/
UC1L is used in mid-level installed sound, rental, and concert sound
applications. Six frequency range variations are available.
Controls and Connectors
10
11
12
1.
2.
3.
4.
5.
6.
Antenna
Power/Battery Fuel Gauge LEDs
Power ON/OFF Switch
Input Connector
Rf/Audio Mute Switch Input Connector
Input Attenuation Control
7.
8.
9.
10.
11.
12.
Audio Gain Control
Group Rotary Switch
Channel Rotary Switch
Battery Compartment
Battery Cover Release Tabs
Battery Compartment Cover
Figure 1. UC1 Controls and Connectors
Service Note: Shure recommends that all service procedures be
performed by a Factory-Authorized Service Center or that the
product be returned directly to Shure Brothers Inc.
E1998, Shure Brothers Inc.
25A1043 (RI)
Printed in U.S.A.
Shure UC1 Body-Pack UHF Transmitter
Circuit Description
LIMITER CONTROL INPUT
MIC. /
INSTR.
BATTERY
MGMT.
& FUEL
GAUGE
TONE KEY
CIRCUIT
ON / OFF
SWITCH
UNREG. PWR.
AUDIO
OUT
TONE KEY
LIMITER
CONTROL OUTPUT
+5v
+5V
REG.
REMOTE
MUTE
FROM
BATT.
Σ
MIC. /
INSTR.
CALL ID
TONE CONTROL
OFF / MUTE DETECT
CONTROL
MCU
PLL CONTROL
FET
BYPASS
EEPROM
(MEM)
PWR.
HOLD
CIRCUIT
SYNTH.
GROUP
RF POWER
RF MUTE
CHANNEL
RF MUTE
AUDIO IN
VCO
Figure 2. UC1 Circuit Block Diagram
Audio Section
Domestic Models
The audio signal enters the audio board at J204, pin 1. The signal
then enters a switchable 20 dB pad made up of SW203, R203, R204,
C204, and C206. The back-to-back diodes, U206, are used to keep
the op-amp from snapping to the rail and reverse-phasing when the
maximum input voltage range is exceeded.
The signal is ac-coupled through C205 into a 40 dB (30 dB for
J frequencies) user-adjustable gain stage around amplifier U2. This
gain stage is externally accessible to the user. Due to its topology, it is
a unique stage because it is non-inverting and allows for a gain less than
unity. Resistors R205 and R207 set up a half-supply bias, and R206 sets
the ac input impedance.
The amplified audio signal then passes through a pre-emphasis
network before entering the compression stage. R221, R222, C215,
and C216 set up two corners for the pre-emphasis network. The preemphasis network feeds the NE575 compander, U203, which utilizes
Service Procedures
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
an external amplifier, U202B. U203 performs a 2:1 logarithmic compression of the audio signal.
Transistors Q201 and Q202, with crystal Y201, form the tone key
oscillator circuit that provides a stable, continuous 32.768 kHz sine
wave. Q204 buffers the tone key signal before it is added to the audio
signal. The tone key signal is used in the receiver to provide audio output only when the tone key signal is present in the transmitted signal.
If the tone key or the transmitter is turned off, the receiver is muted.
Q211 acts as a switch for toggling the tone key ON/OFF. It is controlled from the microprocessor, via the TONEMUTE0 signal. The tone
key signal, along with the processed audio signal, is then fed to a summing amplifier, U201A. After passing through the ac coupling capacitor,
C240, the signal is then fed to the rf module.
The battery meter circuit is comprised of comparator U208 and
LEDs D201, D202, D203, and various resistors. When the battery circuit
is less than 6.5 Vdc, the output of U208, pin 13, changes low, the red
LED illuminates, and the tone-key level increases. The receiver then
utilizes the amplitude of the tone-key to indicate that the transmitter
battery is low.
A 9 Vdc battery provides power to the audio printed circuit board
(pcb) through switch SW202. FET Q217 provides electrical reverse
battery protection. 9 Vdc enters U205, a low-dropout 5 Vdc regulator,
and gives a clean regulated 5 Vdc supply to run the audio circuitry.
ETSI Models
This transmitter uses the same board as the non-ETSI system,
except that it requires a different topology and different parts.
A limiter is inserted between the pre-emphasis and the compressor
to limit the occupied bandwidth. The buffer after the gain stage, U201A,
is now an inverter with pre-emphasis and 20 dB of attenuation.
Previously bypassed, the expander side of U203 is now activated
and used as a limiter. A sample of the audio is taken from the limiter
output (U203, pin 6) and sent to a control circuit which detects signals
from a limiting threshold.
The comparator then sends a control signal to U202, pin 5, which
clamps the signal.
Rf Section
Processed audio enters R149, an internal potentiometer that is
adjusted for 45 kHz deviation (100% modulation for UA, MA, and MB
frequencies), with a –7.2 dBV (0.355 Vrms) 1 kHz tone at the output
of the front audio stage (U201, pin 1). For KK frequencies, R243 is
adjusted for 40 kHz deviation. For JB frequencies, R149 is adjusted for
5 kHz deviation with –63.2 dBV, 1 kHz tone at the input to the transmitter.
25A1043 (RI)
Characteristics
Shure UC1 Body-Pack UHF Transmitter
The audio is then fed to the tuning voltage pin of the voltagecontrolled oscillator (VCO) and modulates the carrier directly.
Using a phase-locked loop (PLL) frequency synthesized system
eliminates the need for multiplier stages and results in a much higher
degree of spectral purity. The VCO is shielded to prevent external rf
fields from affecting its operation.
Regulated 5 Vdc power is provided to ensure frequency stability with
changes in battery voltage.
The VCO can tune from 782 MHz to 810 MHz with a 1 Vdc to 4 Vdc
tuning voltage range; different VCOs are required for MB and KK frequency models. At the output of the VCO, the rf signal splits into two paths.
The output of the VCO is coupled by C134 to the frequency control
pin of the synthesizer, U104, pin 8. The internal circuitry of the synthesizer divides the signal, as necessary, to the desired reference frequency
of 125 kHz. The synthesizer contains a reference oscillator circuit operating from a 4.0 MHz quartz crystal, Y101, that is adjusted by trimmer
C123. The transmitter output frequency is user-selectable in 125 kHz
increments, from 782 MHz to 806 MHz. Frequency range and increment
size vary for each model.
Frequency selection is made via microprocessor U101, which interfaces the user by means of the mode/select switches. The output of the
synthesizer is a series of pulses which are integrated by a passive loop
filter, R121, C130, R122, C129, C130, R123, and C132, to produce a
control voltage signal. The control voltage signal is then connected to
the VCO through amplifier U106A, which is used to isolate the PLL filter
from the audio modulation signals.
The VCO output is also coupled to an rf power amplifier through a
resistive pad consisting of R127, R128, R129, and R130. The signal is
then low-pass filtered through U107. The signal is coupled through C144.
Transistor Q102 acts as an rf pre-amplifier stage with typically 8 dB
of gain. R131, R132, and R133 provide dc bias to Q102. C145, C146,
C147, C149, C150, and L111 are used to decouple the rf off the emitter
of Q102, Vcc, and +9 Vdc supply voltages.
C152 couples the output of Q102 to low-pass filter U108. The signal
is then low-pass filtered through U108, and then coupled through C157.
Q104 acts as an rf amplifier stage with typically 16 dB of gain. L110,
R136, R137, and R138 provide dc bias to Q102. C160, C161, C162,
C163, C164, C165, and L114 are used to decouple the rf off the emitter
of Q104, Vcc, and +9 Vdc supply voltages.
L115 and C167 match the output of Q104 to low-pass filter U109.
The signal is coupled through C173 to the output antenna, W101.
The transmitter can deliver a maximum of +17 dBm (50 mW) to
the 50Ω antenna. During transmitter power-up and frequency selection,
the rf power is muted by bringing the gate of Q103 and Q105 high. The
RFUNMUTE signal is 5 Vdc. This provides approximately 45 dB rf attenuation until the PLL has locked.
Characteristics
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
The transmitter is unmuted by bringing the gate low (RFUNMUTE).
During transmitter power OFF conditions, the rf power is first muted by
bringing the base of Q103 and Q105 high. When the rf is muted this
way, the carrier signal of the transmitter is not allowed to drift off
frequency during power ON or OFF conditions.
When the external mute switch is closed, the ring and sleeve on the
jack are connected, or the tip and sleeve can be connected, depending
on how the switch is wired.
If the tip is connected to the sleeve, this grounds the IRQ signal
line that is connected to the microprocessor. Then, the 33 kHz tone key
signal is muted (TONEMUTE1). The transmitter rf power is muted by
bringing the base of Q103 and Q104 high (RFMUTE1). Finally, the rf
power is then turned off via the RFOFF1 signal. This is done by reducing
the Vcc line to the VCO and the last rf amps.
If the ring is connected to the sleeve, this grounds the TKMUTE1.
The TKMUTE1 grounds Q4 at the output of the tone key oscillator circuit.
This mutes the audio signal immediately.
Transmitter Display Board
UHF Body-Pack Transmitter Digital Section
The digital section contains several circuitry blocks.
Microcontroller Section
The microcontroller section consists of a U101 microcontroller. The
rotary switches indicate the UHF frequency group and channel. A 4.000
MHz oscillator provides the operating frequency to the microcontroller.
The oscillator circuit includes C117, C118, and Y102. U103, R106, and
C120 form the reset circuit. U103 is the reset IC that resets the U101
microcontroller if the 5 Vdc normal operating voltage falls below 4.3 Vdc.
R115 and C119 form the power supply filter circuit.
Memory Section
The memory section consists of U102, a non-volatile Electrically
Erasable / Programmable Read Only Memory (EEPROM) that stores the
mapping of compatible groups and channels. The microcontroller serially
communicates with this part via data and clock lines to read the frequency corresponding to the group and channel position. Ability to write to
this memory occurs during factory programming only.
During normal usage, this memory is used as a look-up table only.
Additional detail about the contents of EEPROM is covered in the following sections.
R103 and R108 resistors allow the clock and data lines to be driven
independently of the microcontroller port pin states during in-circuit
programming of EEPROM.
25A1043 (RI)
Characteristics
Shure UC1 Body-Pack UHF Transmitter
Battery Management Section
The microcontroller provides for low battery shutdown. The shutdown threshold is 1.88 Vdc ± 10%. A voltage lower than the shutdown
threshold on pin 17 of the U101 microcontroller shuts down the transmitter. Resistors R104 and R105 divide down the battery voltage for the
microcontroller. A battery voltage of less than 5.65 Vdc shuts down the
transmitter.
This auto shutdown disables the audio tone key mix, mutes the rf
power output, and power downs the rf output amplifier section. The current draw from a 9 Vdc battery in this state is 45 mA, and the battery fuel
gauge is functional. Turning off the power switch must completely shut
off the transmitter.
The audio circuit description provided the battery fuel gauge circuit
description.
Rotary Switches for Frequency Selection
A 10-position Group switch, S101, and a 16-position Channel switch,
S102, select the transmitter frequency. Both rotary switches share the
same U101 microcontroller port pins, 3 through 6, for a multiplexed
switch read operation.
Pins 7 and 8 of the U101 microcontroller select the individual
switches. Resistors R109 through R112 are the pull-ups for the switch
position read. Diode packs D101 through D104 isolate the switches during a multiplexed read operation.
The multiplexed switch read system does not allow switch change
detection based on interrupts. Also, the switches cannot be constantly
scanned to determine changes, because the scanning frequency being
in audio range is difficult to filter out.
In a steady state, the switch selector common pins are inputs to the
U101 microcontroller pins 7 and 8. Pins 3 through 6 are outputs. In this
state, pins 4, 5, and 6 are held low, while pin 3 is held high. This forces a
logic high level on the switch selector pins if the switches are set on odd
positions. If the switches are set on even positions, the contact on pin 1
is open from the switch common pin, and the pull-down resistors, R114
and R115, force the logic low to pins 7 and 8 of U101.
Any switch change is made by a state toggle from odd to even, or
vice versa. Only this change can be detected and is followed by a multiplexed switch read. In this case, U101 pins 7 and 8 become selectively
grounded outputs to read the selected switch’s state on pins 3 through 6.
A multiplexed switch read is preceded by tone key and rf mutes.
This mutes the audio in the receiver to allow a quiet change to another
frequency.
Characteristics
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Power Switch and Remote Mute Switch Interface
When a transmitter is turned off, the PWRDN1 signal goes to logic low
on U101, pin 19. The same signal is also forced low when a remote
mute switch closes the tip contact to the sleeve ground.
The microcontroller treats both of these events in a similar manner.
It immediately disables the tone key, and the power hold circuit automatically kicks in to bypass the power switch. Followed by 500 msec.
of delay, the rf is muted and also turned off.
The power hold circuit is also disabled at this point. If it is the power
off condition, then the transmitter is shut off. Otherwise, it is the remote
mute condition, and the transmitter waits here for unmute to occur.
PWRDN1 is pulled up back to logic high level when unmute occurs.
The rf section repowers and is unmuted, followed by tone key enable
to completely recover from the remote mute condition. When a remote
mute switch closes the ring contact to the sleeve ground, the TKMUTE1
signal goes to a logic low that immediately mutes the audio.
25A1043 (RI)
Characteristics
Shure UC1 Body-Pack UHF Transmitter
Notes
This page intentionally left blank.
Notes
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Functional Test
Verify operation and reported malfunction, referring to the product
User Guide for a description of the unit as well as information on its
operation, troubleshooting, and technical data.
Disassembly and Assembly
! CAUTION !
Observe precautions when handling this static-sensitive device.
Disassembly
1. Open the battery compartment and remove the battery.
2. Remove the belt clip.
3. With the battery compartment open, remove the four screws
from the back of the case.
4. Lift the top half of the transmitter case away to expose the
printed circuit boards (pcbs).
5. Lift the pcbs out of the transmitter case.
Figure 3. UC1 Disassembly
25A1043 (RI)
Functional Test
Shure UC1 Body-Pack UHF Transmitter
Reassembly
After completing all repairs and alignment, reassemble the UC1:
1. Place the printed circuit boards back into the case, making sure
the multi-pin connectors on the board mate and the TINI QG/
LEMO connector is seated correctly.
2. Reassemble the transmitter by performing the disassembly steps
in reverse order.
Disassembly and Assembly
10
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Service Procedures
Measurement Reference
dBu is a measure of voltage, and dBm is a measure of power.
For example, the HP8903 should be labeled dBu instead of dBm
because it is a voltage measurement. These two terms are often used
interchangeably even though they have different meanings.
Audio levels in dBu are marked as dBm on the HP8903.
dB Conversion Chart
0 dBV = 2.2 dBu
0 dBu = 0 dBm, assuming the load = 600 Ω
Test Equipment
Most test equipment needed is described in the Shure Wireless
Service Equipment Manual. The following test equipment (or approved
equivalent) is also needed.
Table 1
Test Equipment
Equipment Type
Model
Audio analyzer
*Hewlett-Packard 8903B
Digital multimeter
Fluke 87
Cable
PT1843
Frequency counter
Hewlett-Packard 53181A
Rf signal generator
Hewlett-Packard 8656B
Spectrum analyzer
Hewlett-Packard 8590L
Shure UC4 receiver
Shure UC4
*Audio levels in dBu are marked as dBm on the HP8903B.
Test Equipment Set-Up
The alignment procedure is sequential and does not change,
unless specified.
1. Use RG58 or any other low-loss, 50 Ω test cables for all
rf connections. For JA, JB frequencies, use an adapter cable.
2. Keep the test cables as short as possible.
3. Include the insertion loss of the cables and the connectors
for all rf measurements.
4. Dc voltages are present at most rf test points. Use dc blocks
to protect the test equipment, if necessary.
25A1043 (RI)
11
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
C123
Test Set-Up
Q3
TP131
*R144
U501
L115
TP102
TP120
TP110
*J103
TP106
TP107
TP104
TP17
TP16
RED
+ 5V
GND
TP8
TP4
TP14
TP12
TPGND1
Q204
U208
Q220
TP7
TP239
+ 9V
*R144 and J103 are for JA, JB frequencies only.
Q201 Q202
Q218
J202
Q1
Q222
J203
C119
U201
TPAUD1
Q215 Q216
TP6 TP10
L208
Y103
TP21
L205
TP19
+ 9V
U701
Q221
Q223
TP13 TP9
TP109
Q219
TP2
TP18
C246
TP108
S101
W101
TPA1
STR1
GREEN
TP111
TP103
TP+5
U203
TP3
S102
C510
Q104
TP1
C203
R149
U108
U2
C208
TP130
VCO
J204
U1
D206
SIDE 1
C130
TBIAS1
Q2
TPMIC1
TP5
PAD
J202
D G
TBIAS1
SW203
J301
J401
SIDE 2
C206
C223
C257
C256
R7
D101
TPA1
C255
C220
TP+5
TP18
TP9
TP2
D203
D102
U205
TP13
Q4
D202
TP108
TP21
TPAUD1
D201
D103
C219
J201
TP19
C240
TP4
TP14
TPGND1
Y201
TP239
J101
D104
TP8
+ 9V
TP120
Y102
Q213
TP10
TP103
+ 5V
Q217
TP7
Q103
U107
Q101
U103
+ 9V
TP16
TP12
TP6
TP109
TP17
TP111
TP104
TP130
TP5
C176
TP3
U104
U106
TP1
SW202
Y101
D105
4.000
TP102
C176
C225
TPMIC1
4.000
+ 9 Vdc
Q105
TP110
U109
TP106
TP107
U102
W101
PAD
Figure 4. UC1 Major Test Component Locations
1. Use the PT1843 cable to connect the rf-digital board and the
audio board through the 11-pin board interconnects (J101, J201,
side 2).
2. Apply +9 Vdc across the battery terminals (J202, J203, side 1).
3. Set audio GAIN potentiometer (R7, side 2) to minimum
(full counter-clockwise ).
4. Rf power and tone key level measurements are made by
connecting W101 (rf output) to the spectrum analyzer. Use
the frequency counter to measure frequency. For JA, JB
frequencies, connect J103 (rf output) to the spectrum analyzer
and frequency counter.
5. See Table 2 for frequency settings.
Service Procedures
12
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Alignment
Alignment Set-Up
Table 2 lists the group carrier frequencies and
tuning voltages for all the service tests that follow.
Table 2
Group Carrier Frequencies and Tuning Voltages
(in order by carrier frequency)
25A1043 (RI)
Group
Group
Code
Group
Switch
(S101)
Channel
Switch
(S102)
Carrier
Frequency
(MHz)
VCO Tuning
Voltage
(TP130)
Deviation
(kHz)
UA
805.500
3.7
45
MB
805.500
1.8
15
JA
805.500
3.5
JB
807.500
3.7
KK
851.125
3.5
15
MC
–
–
–
–
–
–
13
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
Frequency
Use this service procedure to correctly align the transmitter’s
operating (output) frequency. C510 tunes the voltage-controlled
oscillator (VCO) to the operating frequency selected, with a 1 – 4 Vdc
tuning range.
C123 adjusts the reference oscillator on the synthesizer.
DC VOLTMETER
SIDE 1
C123
–
TP130
VCO
FREQUENCY COUNTER
C510
R149
*R144
U501
S102
(GREEN)
CH 2
*J103
CH 1
S101
(RED)
GND
W101
J202
*R144 and J103 are for JA, JB frequencies only.
UC1 Transmitter
Frequency Counter
Power: ON
Operating freq: See Table 2
J201
DC Voltmeter
Operating freq: See Table 2
Connect + : TP130
Connect CH 2: W101 and GND
For JA, JB use
J103 and GND
Connect – : J202 (ground)
Figure 5. UC1 Frequency Alignment Test Set-Up
1. Remove the antenna and connect the 50 Ω cable, center
conductor to W101, and shield to GND, as shown in Figure 5.
(For JA, JB frequencies, use J103 and GND.)
2. Connect the BNC cable end to the frequency counter, CH 2.
3. Measure the dc voltage at TP130 (tuning voltage line) and
ground (GND).
4. Use the pink torey to adjust the VCO trimmer, C510, until the
voltmeter reading equals that shown in Table 2, ± 0.125V..
5. Use the blue torey to adjust the variable capacitor, C123, until
the frequency counter measurement matches the desired
frequency, within ± 1 kHz.
6. Disconnect the test cable from the frequency counter.
7. Use the test set-up and equipment settings in Figure 6 for
the next test, the power output measurement.
Service Procedures
14
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Power Output Measurement
The output power measurement ensures that the output signal is
strong enough for sufficient range when the system is in use. The output
power measurement also verifies that the output power is not above the
specified maximum level, to ensure compliance with regulatory agencies’
standards.
DC VOLTMETER
SPECTRUM ANALYZER
SIDE 1
C123
–
C510
*R144
U501
R149
TP130
VCO
S102
(GREEN)
*J103
S101
GND
(RED)
W101
J202
*R144 and J103 are for JA, JB frequencies only.
UC1 Transmitter
Spectrum Analyzer
Power: ON
Frequency: See Table 2
Operating freq: See Table 2
Span: 200 MHz
J201
DC Voltmeter
Connect + : TP130
Connect – : J202 (ground)
Reference voltage: 20 dBm
Peak search: ON
Signal track: ON
Marker: ON
Figure 6. UC1 Power Output Measurement Test Set-Up
1. Remove the BNC cable end from the frequency counter and
connect it to the 50 Ω input of the spectrum analyzer. Use the
equipment settings shown in Figure 6.
2. Measure the output power. The output power should be:
UA, MB, MC frequencies:
16 + 1 / – 2 dBm
KK frequencies:
14 + 1 / – 2 dBm
JA, JB frequencies:
Adjust R144 to obtain
8.8 ± 0.5 dBm.
3. Turn the UC1 power OFF.
4. Remove the BNC end of the cable from the spectrum analyzer,
but leave the bare end soldered to the printed circuit board (pcb).
(For JA, JB frequencies, leave the adapter cable connected to
J103.)
25A1043 (RI)
15
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
Deviation Reference Voltage: Using a UC4 or U4S Receiver
Deviation must be set to make sure the companding systems between the transmitter and receiver correctly track each other. The level
coming out of the transmitter’s audio compressor must match the level
going into the receiver’s audio expander. A fixed gain structure does not
ensure an exact match, primarily because of variations in voltagecontrolled oscillators (VCOs).
This test requires a UC4 or U4S receiver and is designed to tune the
transmitter regardless of the accuracy of the receiver’s tuning. However,
it is recommended that a properly-tuned receiver be used to perform the
transmitter deviation adjustment.
Be sure to use a KK model receiver when tuning a KK model transmitter.
UC4 RECEIVER (FRONT)
SQUELCH
UC4 RECEIVER (BACK)
S501
(TONE KEY SWITCH)
TK ON
TK OFF
DC BLOCK
AUDIO ANALYZER
RF SIGNAL GENERATOR
NOTE: DC VOLTAGES ARE PRESENT AT MOST
RF TEST POINTS. USE A DC BLOCK ON THE
RF SIGNAL GENERATOR TO PROTECT
TEST EQUIPMENT.
UC4 Receiver
Audio Analyzer
Output: Unbalanced
Gain: Maximum
Squelch: Mid
Measurement: AC level
Filters:
Low-Pass (30 kHz): ON
Tone Key (S501): OFF
High-Pass (400 Hz): ON
Operating freq: See Table 2
Rf Signal Generator
INT: FM
INT: 1 kHz
Output Amplitude: –60 dBm
Frequency: See Table 2
Modulation:
See Table 2
Figure 7. Deviation Reference Voltage Test Set-Up, Using a UC4 or U4S Receiver
1. See Figure 7 for equipment test set-up and equipment settings.
2. Connect the rf signal generator output to the UC4 receiver
antenna input (A or B).
3. Turn the UC4 receiver on and set switch S501 inside the UC4
receiver to the OFF position to disable the tone key function.
4. Connect the audio voltmeter to the receiver’s unbalanced output.
5. Measure the output voltage.
Record this voltage. This is the deviation reference voltage.
Service Procedures
16
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Deviation Adjustment Voltage: Using a UC4 or U4S Receiver
AUDIO ANALYZER
J301
TP3
R149
UC1, SIDE 2
UC1, SIDE 1
UC1 Transmitter
Audio Analyzer
Power: +9 Vdc
Measurement: AC level
Gain: Minimum
Output: 1 kHz
Filters:
Low-Pass (30 kHz): ON
High-Pass (400 Hz): ON
Figure 8. Deviation Adjustment Voltage Test Set-Up,
Steps 1 through 4, Using a UC4 or U4S Receiver
1. Disconnect the rf signal generator from the UC4 receiver.
Make sure the tone key switch (S501) is in the ON position.
2. Use the BNC to TINI QG cable to connect the audio analyzer
output to the MIC input of the transmitter (J301).
3. Set the audio analyzer to 1 kHz.
4. Turn the UC1 power back ON.
5. Adjust the UC1 audio input level using the audio analyzer output
to get the following readings at TP3, ± 0.02 dB:
Model:
MB, MC
JA, JB
– 16.3 dBu
– 23.47 dBu
UA
–6.8 dBu
KK
– 15.3 dBu
6. See Figure 9 for equipment set-up and equipment settings for
steps 7 through 8.
25A1043 (RI)
17
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
Deviation Adjustment Voltage: Using a UC4 or U4S Receiver
AUDIO ANALYZER
S501
(TONE KEY SWITCH)
R149
W101
GND
UC4 Receiver
UC1 Transmitter
Output: Unbalanced
Gain: Maximum
Power: + 9 Vdc
Gain: Minimum
Squelch: Mid
UC1, SIDE 1
Audio Analyzer
Measurement: AC level
Output: 1 kHz
Filters:
Tone key (S501): ON
Low-Pass (30 kHz): ON
High-Pass (400 Hz): ON
Figure 9. Deviation Adjustment Voltage Test Set-Up,
Steps 7 through 8, Using a UC4 or U4S Receiver
7. Connect the BNC end of the test cable that is soldered to W101
and GND to the antenna A or B inputs.
8. Turn ON the UC1 and adjust R149 until the audio volt-meter
connected to the unbalanced output of the UC4 reads the same
as the deviation reference voltage, measured above, ± 0.1 dB.
R149 adjusts the deviation for 45 kHz, 100% modulation.
Service Procedures
18
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Deviation Reference Voltage: Using a Modified SC4 IF Receiver
Deviation tests can also be performed using a modified SC4 IF
receiver. For instructions on modifying an SC4 receiver, consult the
Shure Service Equipment manual.
ZAD–1 MIXER
MODIFIED SC4 IF RECEIVER
ANTENNA INPUT B
AUDIO OUT
TONE KEY SWITCH: OFF
DC BLOCK
AUDIO ANALYZER
RF SIGNAL GENERATOR
NOTE: DC VOLTAGES ARE
PRESENT AT MOST RF TEST
POINTS. USE A DC BLOCK
ON THE RF SIGNAL GENERATOR
TO PROTECT TEST EQUIPMENT.
SC4 IF Receiver
Audio Analyzer
Output: Unbalanced
Gain: Maximum
Squelch: Mid
Measurement: AC level
INT: FM
Filters:
Low-Pass (30 kHz): ON
Tone Key switch: OFF
Rf Signal Generator
INT: 1 kHz
Output Amplitude: + 7 dBm
High-Pass (400 Hz): ON
Operating freq: See Table 2
Frequency: 10.7 MHz
Modulation:
See Table 2
Figure 10. Deviation Reference Voltage Test Set-Up,
Using a Modified SC4 IF Receiver
1. See Figure 10 for equipment test set-up and equipment settings.
2. Connect the rf signal generator output to the input port L (local
oscillator) of a Zad-1 mixer
3. Connect the output port I (intermediate frequency) of the Zad–1
mixer to antenna input B of the SCR IF receiver.
4. Turn the SC4 IF receiver ON and set the tone key switch on the
front panel of the SCR IF receiver to OFF.
5. Connect the audio voltmeter to the receiver’s unbalanced output.
6. Measure the output voltage.
Record this voltage. This is the deviation reference voltage.
Use the same Zad-1 mixer connections for the next adjustment test.
25A1043 (RI)
19
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
Deviation Adjustment Voltage: Using an SC4 IF Receiver
AUDIO ANALYZER
J301
TP3
R149
UC1, SIDE 2
UC1, SIDE 1
UC1 Transmitter
Audio Analyzer
Power: +9 Vdc
Measurement: AC level
Gain: Minimum
Output: 1 kHz
Filters:
Low-Pass (30 kHz): ON
High-Pass (400 Hz): ON
Figure 11. Deviation Adjustment Voltage Test Set-Up,
Steps 1 through 5, Using a Modified SC4 IF Receiver
1. Disconnect the rf signal generator from the SC4 receiver.
2. Set the SC4 tone key switch on the SC4 front panel to ON.
3. Use the BNC to TINI QG cable to connect the audio analyzer
output to the MIC input of the transmitter (J301).
4. Set the audio analyzer frequency to 1 kHz.
5. Turn the UC1 power back ON.
6. Adjust the UC1 audio input level using the audio analyzer output
to get the following readings at TP3, ± 0.02 dB:
Model:
MB
JA, JB
– 16.3 dBu
– 23.47 dBu
UA
–6.8 dBu
KK
– 15.3 dBu
See Figure 12 for equipment set-up and settings for steps 7 through 9.
Service Procedures
20
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Deviation Adjustment Voltage: Using a Modified SC4 IF Receiver
ZAD–1 MIXER
TRANSMITTER
AUDIO
IN
ANTENNA
OUTPUT
MODIFIED SC4 IF RECEIVER
ANTENNA INPUT B
AUDIO OUT
TONE KEY SWITCH: ON
DC BLOCK
AUDIO ANALYZER
RF SIGNAL GENERATOR
NOTE: DC VOLTAGES ARE
PRESENT AT MOST RF TEST
POINTS. USE A DC BLOCK
ON THE RF SIGNAL GENERATOR
TO PROTECT TEST EQUIPMENT.
SC4 IF Receiver
Output: Unbalanced
Gain: Maximum
UC1 Transmitter
Power:
Gain:
+ 9 Vdc
Audio Analyzer
Measurement:
Minimum
Output:
Squelch: Mid
Tone Key switch: ON
Rf Signal Generator
AC level
INT: FM
1 kHz
INT: 1 kHz
Filters:
Output amplitude: + 7 dBm
Low-Pass 30 kHz:
ON
Modulation: See Table 2
High-Pass 400 Hz:
ON
Frequency: Oper. Freq.
minus 10.7
MHz
Figure 12. Deviation Adjustment Voltage Test Set-Up,
Steps 7 through 9, Using a Modified SC4 IF Receiver
7. Connect the UC1 rf output test cable BNC end to the input port R
(rf output) of the Zad-1 mixer.
8. Change the rf signal generator frequency to the frequency given
in Table 2, minus 10.7 MHz.
9. Turn ON the UC1 and adjust R149 until the audio volt-meter
connected to the unbalanced output of the UC4 reads the same
as the deviation reference voltage, measured above, ± 0.1 dB.
25A1043 (RI)
21
Service Procedures
Shure UC1 Body-Pack UHF Transmitter
Operating Specifications
After tuning, the unit should meet the following specifications.
Table 3
Operating Specifications
Specification
Minimum
Typical
Maximum
Current drain
50 mA
60 mA
70 mA
Frequency
–1.0 kHz
See Table 2
+1.0 kHz
Audio freq response @ 100 Hz wrt 1 k
–5.0 dB
–4.0 dB
–3.0 dB
Audio freq response @ 10 Hz wrt 1 k
+8.0 dB
+9.0 dB
+10.0 dB
95.0 dB
100.0 dB
–
14.0 dBm
16.0 dBm
17.0 dBm
80.0 dB
85.0 dB
–
14.0 dBm
16.0 dBm
17.0 dBm
80.0 dB
85.0 dB
–
12.0 dBm
14.0 dBm
15.0 dBm
System S/N @ 1% THD, A weighted
85.0 dB
90.0 dB
–
Output power, at J2, with C347 in place
8.3 dBm
8.8 dBm
9.3 dBm
UA:
System S/N @ 45 kHz, A weighted
Output power, UA, without C347
MB, MC
System S/N @ 1% THD, A weighted
Output power, without C347
KK:
System S/N @ 1% THD, A weighted
Output power, without C347
JA, JB:
Service Procedures
22
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Bench Checks
Dc Problems
Make all dc measurements with respect to the rf ground,
unless otherwise specified.
n Verify that the battery voltage is between 6.0 Vdc and 9.5 Vdc.
n Check for +5 Vdc at labeled test points on the audio and rf
boards.
n If incorrect voltage is present, check the biasing resistors’ values.
n Trace the dc back to the battery and check the power switch.
n Look for open coils, cracked parts, reversed polarity capacitors,
and solder shorts.
n If there is a short to ground from 5 Vdc, try to isolate different
parts of the circuit.
n Verify that the rf OFF signal changes from +5 Vdc at power up
and power down to 0 Vdc during normal operation. Trace the
signal to the microprocessor. Q101 should be saturated during
normal operation.
n Verify that the battery voltage appears at U205, pin 6,
(TP +9 Vdc).
Rf Frequency Problems
n If the carrier is out of specification by less than 40 kHz and cannot be corrected by adjusting C123, check the values of C123,
C124, and Y101. If these values are correct, replace Y101. As
a last resort, replace the synthesizer, U104.
n If the carrier frequency is not 782 and 810 MHz, or is unstable,
the loop is unlocked:
Check solder connections at the VCO, microprocessor (traces
LE, D, and CK) and synthesizer, U104.
Check for 4 MHz oscillation at U104, pins 1 and 2. If there is not
4 MHz oscillation, replace the crystal, Y104.
Check the values and polarity of the loop filter: R121, R122,
R123, C129, C130, C131, and C132. Check the bias voltage of
U104, pins 3 and 4; and U106, pin 8. As a last resort, replace
the synthesizer, U104.
The tuning voltage of the VCO at U104, pin 5, should be approximately 3 Vdc when the transmitter is programmed for 800 MHz
operation.
25A1043 (RI)
23
Bench Checks
Shure UC1 Body-Pack UHF Transmitter
Low Rf Output Power
n Check the polarity of the low-pass filters U107, U108, and U109.
(Pin 1 is marked with a dash.)
n Check for missing ground connections.
n Verify the VCO output power at R128 and U104, pin 8.
n Check the dc level at the VCO Vcc pin.
n Isolate the VCO from the rest of the circuit by removing R127,
R128, and C134. The carrier frequency will no longer be locked,
but the output power from the VCO should be approximately
0 dBm.
n If the power out of the VCO is still low, the VCO is bad.
Replace the rf board.
n Verify the dc bias of Q102 and Q104. Verify the rf mute signal
changes from +5 Vdc at power up and power down, to 0 Vdc
during normal operation. If Q103 and Q105 are not saturated
during normal operation, the rf power at the antenna port will be
attenuated by about 45 dB.
n Isolate components starting from the antenna port and working
back to the rf power amp.
n Remove the low-pass filter and check the power OUT of the
amplifier.
n Check the values of the output matching network for Q102 and
Q104, C258, L206, and C256. Look for open coils.
n Check the values of the bypass capacitors.
n As a last resort, replace the transistors, Q102 and Q104.
Excessive Current Drain
n Isolate different sections of the circuit; rf, audio, and digital.
Look for reversed polarity capacitors or wrong resistor values.
Deviation Problems
n If R149 cannot be adjusted to obtain the desired deviation, try to
isolate the problem to the audio or rf section.
n Check the value of R149. To check the rf section, set the transmitter frequency to 800 MHz and verify that the tuning voltage of
the VCO (U104, pin 5) is approximately 3 Vdc.
Bench Checks
24
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Audio Problems
No Tone Key
No tone key means that the 32 kHz tone key sidebands are not visible
when the carrier is viewed on a spectrum analyzer. If tone key levels are
there but are too low, the deviation is off and needs to be recalibrated.
n Apply a 1 kHz tone at a level of 0 dBu to the audio input with
the audio gain pot at minimum.
n If the carrier on the spectrum analyzer does not show any
deviation, check part integrity and audio path continuity between
U201, pin 1, and the VCO.
n If the spectrum analyzer shows a deviated carrier, probe for a
32 kHz signal at TP4 and I246 and continue to the next step.
n If there is a signal at I246 but not at TP4, then the mute circuit
through Q4 or Q211 is being activated. Verify that the logic signal at Q4 and Q211, pin 1, is logic low. If it is low, replace Q4 or
Q211. If it is not low, check the line for a short to +5 V. If there is
no short, the microprocessor is defective and must be replaced.
n If there is a 32 kHz signal at both I246 and TP4, replace R248.
n If there is not a 32 kHz signal at either I246 or TP4, there is
something wrong with the tone key circuit or the tone key supply
voltage. If the tone key supply voltage (U201, pin 7) is less than
2 V, there is a problem with one or more of the following components: R284, R287, R285, R286, C289, Q222, C222. R228.
or R229..
n If the voltage at U201, pin 7, is greater than 2 V, the problem is in
the tone key circuit itself. Check for shorts and opens. Replace
parts in this circuit beginning with the crystal until the 32 kHz
oscillation returns.
No Audio
n View the carrier on the spectrum analyzer. If there are not
32 kHz tone key sidebands around the carrier, follow the steps
above for “No Tone Key.”
n If there are tone key sidebands around the carrier, verify that the
signal generator is properly outputting signal.
n Verify +9 V, half-supply bias, and ground connections to U2.
n Verify +9 V, half-supply bias, and ground connections to U201.
n Follow the audio path from where audio is applied until the point
of discontinuity is reached and replace the appropriate part.
25A1043 (RI)
25
Bench Checks
Shure UC1 Body-Pack UHF Transmitter
Notes
This page intentionally left blank.
Notes
26
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Replacement Parts and Drawings
Product Changes
Six versions of the UC1 and UC1L transmitters are available for use
in various countries. Each version is identified below by country code,
country designation, frequency range, and printed circuit board number.
Parts Designations
The following comments apply to the parts list and the schematic:
Resistors: Unless otherwise noted, all resistors are surface-mount
with 1/10 W rating and 1% tolerance.
Capacitors: Unless otherwise noted, non-polarized capacitors are
surface-mount NPO dielectric types with a 100 V capacity and a 5%
tolerance, and polarized capacitors are tantalum types.
Table 4
UC1 / UC1L Model Frequency Variations
(in order by frequency)
Country
Code
Country
Designation
Frequency
Range
UC1 Printed
Circuit Board #
UC1L Printed
Circuit Board #
MC
Netherlands
774 – 782 MHz
90MC8790H
90MC8791H
UA
U.S.A. and Canada
782 – 806 MHz
90UA8790H
90UA8791H
JA
Japan
797 – 806 MHz
90JA8790H
90JA8791H
MB
Europe
800 – 830 MHz
90MB8790H
90MB8791H
JB
Japan
806 – 810 MHz
90JB8790H
90JB8791H
KK
United Kingdom
838 – 862 MHz
90KK8790H
90KK8791H
Table 5
Replacement Parts
Reference
Designation
25A1043 (RI)
Description
Shure Part
Number
MP1
Antenna
70A8015
MP2
Belt clip
44A8013A
MP3
Bushing
66A308
MP4
Case back
65A8295A
MP5
Case front
65A8294A
MP6
Compression pad
36A8078
MP7
Door
65A8296
MP8
Foam pad
36A8073
27
Replacement Parts and Drawings
Shure UC1 Body-Pack UHF Transmitter
Table 6
Printed Circuit Board Components
Reference
Designation
Description
Shure Part
Number
C123
Capacitor, trimmer, 5 – 40 pF
152F03
C510
Capacitor, trimmer, 1.4 – 3.0 pF
152A04
D101–104
Diode, dual switching, SOT-23
184A07
D105, 206
Diode, signal / switching, SOT-23
184A08
D201
LED, right angle, green
184F32
D202
LED, right angle, yellow
184E32
D203
LED, right angle, SMT, red
184D32
D501
Diode, rf tuning
184A36
J102
Jack, stereo, 35 mm
95A8774
J201
Connector, receptacle
J202,203
Battery contacts
170A08
56A8072A
J204
Connector, strip socket
170C15
J301
Receptacle, male, 4-pin, TINI QG
95A8413
J401
Connector, LEMO (UC1L)
95A8601
Connector, interconnect strip
56D8074
P301,305
Q1,4,211,215,
216,218
Transistor, SOT-23, FET, TMOS
183A30
Transistor, SOT-23, PNP
183A01
Q102,501,502
Transistor
183A48
Q103,105,217
Transistor, power, MOSFET
183A46
Transistor, SOT-23
183A49
Transistor, SOT-23, NPN
183A02
Q101,213
Q104
Q201,202,204,
219,220,221,
222, 223
R7
Potentiometer, gain
46H8014
R149
Potentiometer, trim
146B02
SW202
Switch, toggle, DPST
55A189
SW203
Switch, slide
55A8087
Y101
Crystal, 4 MHz
40A8012
Y201
Crystal, 32.768 kHz
40A8010
IC, dual op amp
188A18
U2
U101
IC, microprocessor, programmed
U102
IC, EEPROM
188A131
U103
IC, detector
188C210
U104
IC, PLL frequency synthesizer
188A265
U201
IC, quad op amp
188A49
U203
IC, compander
188A126
U205
IC, voltage regulator, 5 V
188A115
U208
IC, quad comparator
188A123
U501
Resonator, dielectric
140A14
Replacement Parts and Drawings
28
188D238E
25A1043 (RI)
Shure UC1 Body-Pack UHF Transmitter
Table 7
Group Designators
(in order by frequency)
Frequency
Range
(MHz)
25A1043 (RI)
Country
Designation
Country
Code
R27
kΩ
R28
kΩ
R29
kΩ
R30
κΩ
R31
kΩ
774–782
Netherlands
MC
–
–
–
–
1.0
782–806
US & Canada
UA
–
–
–
–
–
797–806
Japan
JA,JB
–
1.0
–
–
–
800–830
Europe
MB
1.0
–
–
–
–
806–810
Japan
JB
–
–
1.0
–
–
838–862
England
KK
–
–
–
1.0
–
Country
Code
R34
kΩ
R35
kΩ
R36
kΩ
R37
kΩ
R38
kΩ
R39
kΩ
R41
kΩ
MC
–
–
–
–
–
1.0
–
UA
1.0
–
–
–
–
–
–
JA,JB
–
–
1.0
–
–
–
–
MB
–
1.0
–
–
–
–
–
JB
–
–
–
1.0
–
–
–
KK
–
–
–
–
1.0
–
–
29
Replacement Parts and Drawings
Shure UC1 Body-Pack UHF Transmitter
Table 8
Frequency Dependent Components
(in order by frequency)
Frequency
Range (MHz)
Country
Designation
Country
Code
C7
pF
C8
uF
C12
pF
C117
pF
C118
pF
C173
pF
C215
uF
774–782
Netherlands
MC
0.047
0.1
100
–
–
27
2.2
782–806
US & Canada
UA
–
–
–
27
–
797–806
Japan
JA
0.047
0.1
100
27
27
–
2.2
800–830
Europe
MB
0.047
0.1
100
–
–
27
2.2
806–810
Japan
JB
–
–
–
27
27
–
–
838–862
England
KK
0.047
0.1
100
–
–
27
2.2
R3
kΩ
Country
Code
C216
uF
C505
pF
C506
pF
C509
pF
J103
Q2
Q3
R1
kΩ
R2
kΩ
MC
–
3.3
3.3
1.8
–
183A01
183A02
10
1.5
249
UA
0.047
4.7
4.7
1.8
–
–
–
–
4.99
JA
–
4.7
4.7
1.8
170A14
183A01
183A02
10
10
249
MB
–
4.7
4.7
1.8
–
183A01
183A02
10
1.5
249
JB
0.047
4.7
4.7
1.8
170A14
–
–
–
4.99
KK
–
–
–
–
–
183A01
183A02
10
1.5
249
Country
Code
R9
kΩ
R11
kΩ
R12
kΩ
R13
kΩ
R14
κΩ
R15
kΩ
R16
MΩ
R17
MΩ
R18
kΩ
R25
kΩ
R26
kΩ
MC
–
100
100
40.2
100
10
1.0
1.0
22.1
–
–
UA
–
–
–
–
–
–
–
–
1.0
JA
–
100
100
40.2
100
10
1.0
1.0
22.1
–
–
MB
–
100
100
40.2
100
10
1.0
1.0
22.1
–
–
JB
–
–
–
–
–
–
–
–
–
KK
–
100
100
40.2
100
10
1.0
1.0
22.1
–
–
Country
Code
R27
kΩ
R28
kΩ
R29
kΩ
R30
kΩ
R34
kΩ
R35
kΩ
R36
kΩ
R37
kΩ
R38
kΩ
R133
kΩ
MC
1.0
–
–
–
–
–
–
–
–
22.1
UA
–
–
–
–
1.0
–
–
–
–
22.1
JA
–
1.0
–
–
–
–
1.0
–
–
150
MB
1.0
–
–
–
–
1.0
–
–
–
22.1
JB
–
–
1.0
–
–
–
–
1.0
–
150
KK
–
–
–
1.0
–
–
–
–
1.0
22.1
Country
Code
R144
1 kΩ
R286
kΩ
R287
kΩ
R298
kΩ
S101
GRP
S102
CH
U1
Y102
Y103
MC
–
200
UA
–
200
24.9
–
155B11
155A11
183A136
–
140C15
24.9
4.02
155B11
155A11
–
–
140C15
JA
146B02
24.9
–
–
155A11
155B11
183A136
40A8012
–
MB
–
200
24.9
–
155B11
155A11
183A136
–
140C15
JB
146B02
24.9
–
4.02
155B11
155A11
–
40A8012
–
KK
–
200
24.9
–
155B11
155A11
183A136
–
140C15
Replacement Parts and Drawings
30
25A1043 (RI)
UC1 Body-Pack Transmitter
Audio–Rf Printed Circuit Board
Side 1
Shure UC1 Body-Pack UHF Transmitter
25A1043 (RI)
31
Replacement Parts and Drawings
UC1 Body-Pack Transmitter
Audio–Rf Printed Circuit Board
Side 2
Shure UC1 Body-Pack UHF Transmitter
Replacement Parts and Drawings
32
25A1043 (RI)

---

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.2
Linearized                      : No
Create Date                     : 1998:09:18 08:49:41
Producer                        : Acrobat Distiller Daemon 3.01 for HP-UX A.09.01 and later (HPPA)
Author                          : campben
Creator                         : Interleaf, Inc.
Title                           : UC1_srv
Modify Date                     : 1999:07:12 15:05:41
Page Count                      : 32

EXIF Metadata provided by EXIF.tools