Shure orporated UC1B User Manual UC1 srv

Shure Incorporated UC1 srv

Contents

User Manual

E1998, Shure Brothers Inc. Printed in U.S.A.25A1043 (RI)Service ManualUC1 / UC1L Body-PackUHF TransmitterCharacteristicsGeneralThe Shure UC1/UC1L Body-Pack Transmitter is microprocessor-controlled, 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 Connectors1231. Antenna2. Power/Battery Fuel Gauge LEDs3. Power ON/OFF Switch4. Input Connector5. Rf/Audio Mute Switch Input Connector6. Input Attenuation Control7. Audio Gain Control8. Group Rotary Switch9. Channel Rotary Switch10. Battery Compartment11. Battery Cover Release Tabs12. Battery Compartment CoverFigure 1. UC1 Controls and Connectors451011127896Service Note: Shure recommends that all service procedures beperformed by a Factory-Authorized Service Center or that the product be returned directly to Shure Brothers Inc.
Shure UC1 Body-Pack UHF Transmitter2 25A1043 (RI)Service ProceduresCircuit DescriptionCONTROLPLL CONTROL MCU EEPROM(MEM)OFF / MUTE DETECT+5VREG.REMOTEMUTEGROUP CHANNELSYNTH.RF POWER RF MUTE RF MUTEVCOFROMBATT. UNREG. PWR.+5vAUDIO INPWR.HOLDCIRCUITMIC. /INSTR.ON / OFFSWITCHFETBYPASSTONE KEYCIRCUITΣTONE CONTROLTONE KEYCALL IDBATTERYMGMT.& FUELGAUGEAUDIOOUTMIC. /INSTR.LIMITERCONTROL OUTPUTLIMITER CONTROL INPUTFigure 2. UC1 Circuit Block DiagramAudio SectionDomestic ModelsThe audio signal enters the audio board at J204, pin 1. The signalthen 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 thanunity. Resistors R205 and R207 set up a half-supply bias, and R206 setsthe 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 pre-emphasis network feeds the NE575 compander, U203, which utilizes
Shure UC1 Body-Pack UHF Transmitter325A1043 (RI)Characteristicsan external amplifier, U202B. U203 performs a 2:1 logarithmic compres-sion of the audio signal.Transistors Q201 and Q202, with crystal Y201, form the tone keyoscillator circuit that provides a stable, continuous 32.768 kHz sine wave. Q204 buffers the tone key signal before it is added to the audiosignal. The tone key signal is used in the receiver to provide audio out-put 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 con-trolled from the microprocessor, via the TONEMUTE0 signal. The tonekey signal, along with the processed audio signal, is then fed to a sum-ming 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 circuitis less than 6.5 Vdc, the output of U208, pin 13, changes low, the redLED 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 ModelsThis 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 compressorto 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 activatedand 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 signalsfrom a limiting threshold.The comparator then sends a control signal to U202, pin 5, whichclamps the signal.Rf SectionProcessed 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.
Shure UC1 Body-Pack UHF Transmitter4 25A1043 (RI)CharacteristicsThe audio is then fed to the tuning voltage pin of the voltage-controlled 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 higherdegree of spectral purity. The VCO is shielded to prevent external rffields from affecting its operation.Regulated 5 Vdc power is provided to ensure frequency stability withchanges in battery voltage.The VCO can tune from 782 MHz to 810 MHz with a 1 Vdc to 4 Vdctuning voltage range; different VCOs are required for MB and KK frequen-cy 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 controlpin of the synthesizer, U104, pin 8. The internal circuitry of the synthe-sizer divides the signal, as necessary, to the desired reference frequencyof 125 kHz. The synthesizer contains a reference oscillator circuit oper-ating from a 4.0 MHz quartz crystal, Y101, that is adjusted by trimmerC123. The transmitter output frequency is user-selectable in 125 kHzincrements, from 782 MHz to 806 MHz. Frequency range and incrementsize vary for each model.Frequency selection is made via microprocessor U101, which inter-faces the user by means of the mode/select switches. The output of thesynthesizer is a series of pulses which are integrated by a passive loopfilter, R121, C130, R122, C129, C130, R123, and C132, to produce acontrol voltage signal. The control voltage signal is then connected tothe VCO through amplifier U106A, which is used to isolate the PLL filterfrom the audio modulation signals.The VCO output is also coupled to an rf power amplifier through aresistive pad consisting of R127, R128, R129, and R130. The signal isthen low-pass filtered through U107. The signal is coupled through C144.Transistor Q102 acts as an rf pre-amplifier stage with typically 8 dBof 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 emitterof Q102, Vcc, and +9 Vdc supply voltages.C152 couples the output of Q102 to low-pass filter U108. The signalis 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 emitterof 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. TheRFUNMUTE signal is 5 Vdc. This provides approximately 45 dB rf attenu-ation until the PLL has locked.
Shure UC1 Body-Pack UHF Transmitter525A1043 (RI)CharacteristicsThe transmitter is unmuted by bringing the gate low (RFUNMUTE).During transmitter power OFF conditions, the rf power is first muted bybringing the base of Q103 and Q105 high. When the rf is muted thisway, 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 thejack are connected, or the tip and sleeve can be connected, dependingon 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 keysignal is muted (TONEMUTE1). The transmitter rf power is muted bybringing the base of Q103 and Q104 high (RFMUTE1). Finally, the rfpower is then turned off via the RFOFF1 signal. This is done by reducingthe 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 BoardUHF Body-Pack Transmitter Digital SectionThe digital section contains several circuitry blocks.Microcontroller SectionThe microcontroller section consists of a U101 microcontroller. Therotary switches indicate the UHF frequency group and channel. A 4.000MHz oscillator provides the operating frequency to the microcontroller.The oscillator circuit includes C117, C118, and Y102. U103, R106, andC120 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 SectionThe memory section consists of U102, a non-volatile ElectricallyErasable / Programmable Read Only Memory (EEPROM) that stores themapping of compatible groups and channels. The microcontroller seriallycommunicates with this part via data and clock lines to read the frequen-cy corresponding to the group and channel position. Ability to write tothis 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 follow-ing sections.R103 and R108 resistors allow the clock and data lines to be drivenindependently of the microcontroller port pin states during in-circuit programming of EEPROM.
Shure UC1 Body-Pack UHF Transmitter6 25A1043 (RI)CharacteristicsBattery Management SectionThe microcontroller provides for low battery shutdown. The shut-down threshold is 1.88 Vdc ± 10%. A voltage lower than the shutdownthreshold on pin 17 of the U101 microcontroller shuts down the transmit-ter. Resistors R104 and R105 divide down the battery voltage for themicrocontroller. A battery voltage of less than 5.65 Vdc shuts down thetransmitter.This auto shutdown disables the audio tone key mix, mutes the rfpower output, and power downs the rf output amplifier section. The cur-rent draw from a 9 Vdc battery in this state is 45 mA, and the battery fuelgauge is functional. Turning off the power switch must completely shutoff the transmitter.The audio circuit description provided the battery fuel gauge circuitdescription.Rotary Switches for Frequency SelectionA 10-position Group switch, S101, and a 16-position Channel switch,S102, select the transmitter frequency. Both rotary switches share thesame U101 microcontroller port pins, 3 through 6, for a multiplexedswitch read operation.Pins 7 and 8 of the U101 microcontroller select the individualswitches. Resistors R109 through R112 are the pull-ups for the switchposition read. Diode packs D101 through D104 isolate the switches dur-ing a multiplexed read operation.The multiplexed switch read system does not allow switch changedetection based on interrupts. Also, the switches cannot be constantlyscanned 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 theU101 microcontroller pins 7 and 8. Pins 3 through 6 are outputs. In thisstate, pins 4, 5, and 6 are held low, while pin 3 is held high. This forces alogic high level on the switch selector pins if the switches are set on oddpositions. If the switches are set on even positions, the contact on pin 1is open from the switch common pin, and the pull-down resistors, R114and 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, orvice versa. Only this change can be detected and is followed by a multi-plexed switch read. In this case, U101 pins 7 and 8 become selectivelygrounded 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 anotherfrequency.
Shure UC1 Body-Pack UHF Transmitter725A1043 (RI)CharacteristicsPower Switch and Remote Mute Switch InterfaceWhen a transmitter is turned off, the PWRDN1 signal goes to logic lowon U101, pin 19. The same signal is also forced low when a remotemute 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 auto-matically 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 poweroff condition, then the transmitter is shut off. Otherwise, it is the remotemute 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 enableto completely recover from the remote mute condition. When a remotemute switch closes the ring contact to the sleeve ground, the TKMUTE1signal goes to a logic low that immediately mutes the audio.
Shure UC1 Body-Pack UHF Transmitter8 25A1043 (RI)NotesNotesThis page intentionally left blank.
Shure UC1 Body-Pack UHF Transmitter925A1043 (RI)Functional TestFunctional TestVerify operation and reported malfunction, referring to the productUser 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.Disassembly1. 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 theprinted circuit boards (pcbs).5. Lift the pcbs out of the transmitter case.Figure 3. UC1 Disassembly
Shure UC1 Body-Pack UHF Transmitter10 25A1043 (RI)Disassembly and AssemblyReassemblyAfter completing all repairs and alignment, reassemble the UC1:1. Place the printed circuit boards back into the case, making surethe multi-pin connectors on the board mate and the TINI QG/LEMO connector is seated correctly.2. Reassemble the transmitter by performing the disassembly stepsin reverse order.
Shure UC1 Body-Pack UHF Transmitter1125A1043 (RI)Service ProceduresService ProceduresMeasurement ReferencedBu 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 usedinterchangeably even though they have different meanings.Audio levels in dBu are marked as dBm on the HP8903.dB Conversion Chart0 dBV =2.2 dBu0 dBu =0 dBm, assuming the load = 600 ΩTest EquipmentMost test equipment needed is described in the Shure Wireless Service Equipment Manual. The following test equipment (or approvedequivalent) is also needed.Table 1Test EquipmentEquipment Type ModelAudio analyzer *Hewlett-Packard 8903BDigital multimeter Fluke 87Cable PT1843Frequency counter Hewlett-Packard 53181ARf signal generator Hewlett-Packard 8656BSpectrum analyzer Hewlett-Packard 8590LShure UC4 receiver Shure UC4*Audio levels in dBu are marked as dBm on the HP8903B.Test Equipment Set-UpThe 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.
Shure UC1 Body-Pack UHF Transmitter12 25A1043 (RI)Service ProceduresTest Set-UpR7SW203PADC225C223C257C256C219SIDE 1W101 TP107TP106TP110TP102 TP103GNDU701U108Q104L115Y103U501C130TP131TP5C123S102S101TP108TP109J203J202C119C510TP130TP111+ 5V+ 9VTP120 TP104TP7GREENREDR149L208J204U203U201U208STR1C246Q219Q221Q1Q222U1U2D206Q2TPMIC1C203C208Q3Q223Q204Q201 Q202AEGCBDFHTBIAS1TP3TPA1TP1TP9TP13TP19TP12 TP14 TPGND1TPAUD1TP4L205Q215 Q216Q220TP8TP6 TP10+ 9V TP239TP18TP+5TP17TP16SIDE 2TBIAS1TP1J301SW202D203D202D201Y201TP4TP239TPGND1TPAUD1C240Q4C220C255TP3BDCAFHGE TPMIC1TPA1J201U205Q213Q217TP18 TP+5TP9TP21TP16+ 9VTP14 TP12TP19TP13TP7TP6TP17TP10TP8TP2C206Q218J202J401U106J101Y1024.000U102PADU109U107U104Q103Q105C176Q101D102D103D101C176D104Y1014.000D105TP130TP5U103TP111TP104TP120+ 5V+ 9VTP102TP103TP110TP106TP107W101TP108TP109+ 9 VdcVCOTP2TP21*J103*R144*R144 and J103 are for JA, JB frequencies only.Figure 4. UC1 Major Test Component Locations1. 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 analyzerand frequency counter.5. See Table 2 for frequency settings.
Shure UC1 Body-Pack UHF Transmitter1325A1043 (RI)Service ProceduresAlignmentAlignment Set-UpTable 2 lists the group carrier frequencies and tuning voltages for all the service tests that follow.Table 2Group Carrier Frequencies and Tuning Voltages(in order by carrier frequency)Group GroupCodeGroupSwitch(S101)ChannelSwitch(S102)CarrierFrequency (MHz)VCO TuningVoltage(TP130) Deviation(kHz)UA A 4 0 805.500 3.7 45MB B 1 3 805.500 1.8 15JA C 0 2 805.500 3.5 5JB D 4 2 807.500 3.7 5KK E 5 5 851.125 3.5 15MC – – – – – –
Shure UC1 Body-Pack UHF Transmitter14 25A1043 (RI)Service ProceduresFrequencyUse 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 Vdctuning range.C123 adjusts the reference oscillator on the synthesizer.S101(RED)W101GNDTP130S102(GREEN)FREQUENCY COUNTERDC VOLTMETER+–CH 2CH 1C123R149C510U501VCOSIDE 1J201J202*J103*R144*R144 and J103 are for JA, JB frequencies only.UC1 Transmitter Frequency Counter DC VoltmeterPower: ON Operating freq: See Table 2 Connect + : TP130Operating freq: See Table 2 Connect CH 2: W101 and GNDFor JA, JB useJ103 and GNDConnect – : J202 (ground)Figure 5. UC1 Frequency Alignment Test Set-Up1. 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) andground (GND).4. Use the pink torey to adjust the VCO trimmer, C510, until thevoltmeter reading equals that shown in Table 2, ± 0.125V..5. Use the blue torey to adjust the variable capacitor, C123, untilthe 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 forthe next test, the power output measurement.
Shure UC1 Body-Pack UHF Transmitter1525A1043 (RI)Service ProceduresPower Output MeasurementThe output power measurement ensures that the output signal isstrong enough for sufficient range when the system is in use. The outputpower measurement also verifies that the output power is not above thespecified maximum level, to ensure compliance with regulatory agencies’standards.S101(RED)W101GNDTP130S102(GREEN)DC VOLTMETER+–C123R149C510U501VCOSIDE 1J201J202SPECTRUM ANALYZER*J103*R144*R144 and J103 are for JA, JB frequencies only.UC1 Transmitter Spectrum Analyzer DC VoltmeterPower: ON Frequency: See Table 2 Connect + : TP130Operating freq: See Table 2 Span: 200 MHz Connect – : J202 (ground)Reference voltage: 20 dBmPeak search: ONSignal track: ONMarker: ONFigure 6. UC1 Power Output Measurement Test Set-Up1. Remove the BNC cable end from the frequency counter and connect it to the 50 Ω input of the spectrum analyzer. Use theequipment settings shown in Figure 6.2. Measure the output power. The output power should be:UA, MB, MC frequencies: 16 + 1 / – 2 dBmKK frequencies: 14 + 1 / – 2 dBmJA, 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 toJ103.)
Shure UC1 Body-Pack UHF Transmitter16 25A1043 (RI)Service ProceduresDeviation Reference Voltage: Using a UC4 or U4S ReceiverDeviation must be set to make sure the companding systems be-tween the transmitter and receiver correctly track each other. The levelcoming out of the transmitter’s audio compressor must match the levelgoing into the receiver’s audio expander. A fixed gain structure does notensure an exact match, primarily because of variations in voltage-controlled oscillators (VCOs).This test requires a UC4 or U4S receiver and is designed to tune thetransmitter regardless of the accuracy of the receiver’s tuning. However,it is recommended that a properly-tuned receiver be used to perform thetransmitter deviation adjustment.Be sure to use a KK model receiver when tuning a KK model transmitter.TK ON TK OFFS501(TONE KEY SWITCH)UC4 RECEIVER (BACK)RF SIGNAL GENERATORAUDIO ANALYZER DC BLOCKUC4 RECEIVER (FRONT)ABSQUELCHNOTE: 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 Rf Signal GeneratorOutput: Unbalanced Measurement: AC level INT: FMGain: Maximum Filters: INT: 1 kHzSquelch: Mid Low-Pass (30 kHz): ON Output Amplitude: –60 dBmTone Key (S501): OFF High-Pass (400 Hz): ON Frequency: See Table 2Operating freq: See Table 2 Modulation: See Table 2Figure 7. Deviation Reference Voltage Test Set-Up, Using a UC4 or U4S Receiver1. 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 UC4receiver 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.
Shure UC1 Body-Pack UHF Transmitter1725A1043 (RI)Service ProceduresDeviation Adjustment Voltage: Using a UC4 or U4S ReceiverJ301AUDIO ANALYZERUC1, SIDE 1UC1, SIDE 2TP3R149UC1 Transmitter Audio AnalyzerPower: +9 Vdc Measurement: AC levelGain: Minimum Output: 1 kHzFilters:Low-Pass (30 kHz): ONHigh-Pass (400 Hz): ONFigure 8. Deviation Adjustment Voltage Test Set-Up, Steps 1 through 4, Using a UC4 or U4S Receiver1. 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 outputto get the following readings at TP3, ± 0.02 dB:Model:UA MB, MC JA, JB KK–6.8 dBu – 16.3 dBu – 23.47 dBu – 15.3 dBu6. See Figure 9 for equipment set-up and equipment settings forsteps 7 through 8.
Shure UC1 Body-Pack UHF Transmitter18 25A1043 (RI)Service ProceduresDeviation Adjustment Voltage: Using a UC4 or U4S ReceiverAUDIO ANALYZERUC1, SIDE 1R149S501(TONE KEY SWITCH)W101GNDUC4 Receiver UC1 Transmitter Audio AnalyzerOutput: Unbalanced Power: + 9 Vdc Measurement: AC levelGain: Maximum Gain: Minimum Output: 1 kHzSquelch: Mid Filters:Tone key (S501): ON Low-Pass (30 kHz): ONHigh-Pass (400 Hz): ONFigure 9. Deviation Adjustment Voltage Test Set-Up, Steps 7 through 8, Using a UC4 or U4S Receiver7. Connect the BNC end of the test cable that is soldered to W101and 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 sameas the deviation reference voltage, measured above, ± 0.1 dB.R149 adjusts the deviation for 45 kHz, 100% modulation.
Shure UC1 Body-Pack UHF Transmitter1925A1043 (RI)Service ProceduresDeviation 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 theShure Service Equipment manual.RF SIGNAL GENERATORAUDIO ANALYZERDC BLOCKNOTE: DC VOLTAGES ARE PRESENT AT MOST RF TESTPOINTS. USE A DC BLOCK ON THE RF SIGNAL GENERATOR TO PROTECT TEST EQUIPMENT.RILZAD–1 MIXERMODIFIED SC4 IF RECEIVERANTENNA INPUT B AUDIO OUTTONE KEY SWITCH: OFFSC4 IF Receiver Audio Analyzer Rf Signal GeneratorOutput: Unbalanced Measurement: AC level INT: FMGain: Maximum Filters: INT: 1 kHzSquelch: Mid Low-Pass (30 kHz): ON Output Amplitude: + 7 dBmTone Key switch: OFF High-Pass (400 Hz): ON Frequency: 10.7 MHzOperating freq: See Table 2 Modulation: See Table 2Figure 10. Deviation Reference Voltage Test Set-Up, Using a Modified SC4 IF Receiver1. See Figure 10 for equipment test set-up and equipment settings.2. Connect the rf signal generator output to the input port L (localoscillator) of a Zad-1 mixer3. Connect the output port I (intermediate frequency) of the Zad–1mixer to antenna input B of the SCR IF receiver.4. Turn the SC4 IF receiver ON and set the tone key switch on thefront 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.
Shure UC1 Body-Pack UHF Transmitter20 25A1043 (RI)Service ProceduresDeviation Adjustment Voltage: Using an SC4 IF ReceiverJ301AUDIO ANALYZERUC1, SIDE 1UC1, SIDE 2TP3R149UC1 Transmitter Audio AnalyzerPower: +9 Vdc Measurement: AC levelGain: Minimum Output: 1 kHzFilters:Low-Pass (30 kHz): ONHigh-Pass (400 Hz): ONFigure 11. Deviation Adjustment Voltage Test Set-Up, Steps 1 through 5, Using a Modified SC4 IF Receiver1. 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 outputto get the following readings at TP3, ± 0.02 dB:Model:UA MB JA, JB KK–6.8 dBu – 16.3 dBu – 23.47 dBu – 15.3 dBuSee Figure 12 for equipment set-up and settings for steps 7 through 9.
Shure UC1 Body-Pack UHF Transmitter2125A1043 (RI)Service ProceduresDeviation Adjustment Voltage: Using a Modified SC4 IF ReceiverRF SIGNAL GENERATORAUDIO ANALYZERDC BLOCKNOTE: DC VOLTAGES ARE PRESENT AT MOST RF TESTPOINTS. USE A DC BLOCK ON THE RF SIGNAL GENERATOR TO PROTECT TEST EQUIPMENT.TRANSMITTERANTENNAOUTPUT RILZAD–1 MIXERMODIFIED SC4 IF RECEIVERANTENNA INPUT B AUDIO OUTTONE KEY SWITCH: ONAUDIOINSC4 IF Receiver UC1 Transmitter Audio Analyzer Rf Signal GeneratorOutput: Unbalanced Power: + 9 Vdc Measurement: AC level INT: FMGain: Maximum Gain: Minimum Output: 1 kHz INT: 1 kHzSquelch: Mid Filters: Output amplitude: + 7 dBmTone Key switch: ON Low-Pass 30 kHz: ON Modulation: See Table 2High-Pass 400 Hz: ON Frequency: Oper. Freq. minus 10.7MHzFigure 12. Deviation Adjustment Voltage Test Set-Up, Steps 7 through 9, Using a Modified SC4 IF Receiver7. 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 givenin 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 sameas the deviation reference voltage, measured above, ± 0.1 dB.
Shure UC1 Body-Pack UHF Transmitter22 25A1043 (RI)Service ProceduresOperating SpecificationsAfter tuning, the unit should meet the following specifications.Table 3Operating SpecificationsSpecification Minimum Typical MaximumCurrent drain 50 mA 60 mA 70 mAFrequency –1.0 kHz See Table 2 +1.0 kHzAudio freq response @ 100 Hz wrt 1 k –5.0 dB –4.0 dB –3.0 dBAudio freq response @ 10 Hz wrt 1 k +8.0 dB +9.0 dB +10.0 dBUA:System S/N @ 45 kHz, A weighted 95.0 dB 100.0 dB –Output power, UA, without C347 14.0 dBm 16.0 dBm 17.0 dBmMB, MCSystem S/N @ 1% THD, A weighted 80.0 dB 85.0 dB –Output power, without C347 14.0 dBm 16.0 dBm 17.0 dBmKK:System S/N @ 1% THD, A weighted 80.0 dB 85.0 dB –Output power, without C347 12.0 dBm 14.0 dBm 15.0 dBmJA, JB: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
Shure UC1 Body-Pack UHF Transmitter2325A1043 (RI)Bench ChecksBench ChecksDc ProblemsMake all dc measurements with respect to the rf ground, unless otherwise specified.nVerify that the battery voltage is between 6.0 Vdc and 9.5 Vdc.nCheck for +5 Vdc at labeled test points on the audio and rfboards.nIf incorrect voltage is present, check the biasing resistors’ values.nTrace the dc back to the battery and check the power switch.nLook for open coils, cracked parts, reversed polarity capacitors,and solder shorts.nIf there is a short to ground from 5 Vdc, try to isolate differentparts of the circuit.nVerify that the rf OFF signal changes from +5 Vdc at power upand power down to 0 Vdc during normal operation. Trace thesignal to the microprocessor. Q101 should be saturated duringnormal operation.nVerify that the battery voltage appears at U205, pin 6, (TP +9 Vdc).Rf Frequency ProblemsnIf the carrier is out of specification by less than 40 kHz and can-not be corrected by adjusting C123, check the values of C123,C124, and Y101. If these values are correct, replace Y101. Asa last resort, replace the synthesizer, U104.nIf the carrier frequency is not 782 and 810 MHz, or is unstable,the loop is unlocked: Check solder connections at the VCO, microprocessor (tracesLE, D, and CK) and synthesizer, U104.Check for 4 MHz oscillation at U104, pins 1 and 2. If there is not4 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 ofU104, pins 3 and 4; and U106, pin 8. As a last resort, replacethe synthesizer, U104.The tuning voltage of the VCO at U104, pin 5, should be approxi-mately 3 Vdc when the transmitter is programmed for 800 MHzoperation.
Shure UC1 Body-Pack UHF Transmitter24 25A1043 (RI)Bench ChecksLow Rf Output PowernCheck the polarity of the low-pass filters U107, U108, and U109.(Pin 1 is marked with a dash.)nCheck for missing ground connections.nVerify the VCO output power at R128 and U104, pin 8.nCheck the dc level at the VCO Vcc pin.nIsolate 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.nIf the power out of the VCO is still low, the VCO is bad. Replace the rf board.nVerify the dc bias of Q102 and Q104. Verify the rf mute signalchanges from +5 Vdc at power up and power down, to 0 Vdcduring normal operation. If Q103 and Q105 are not saturatedduring normal operation, the rf power at the antenna port will beattenuated by about 45 dB.nIsolate components starting from the antenna port and workingback to the rf power amp.nRemove the low-pass filter and check the power OUT of the amplifier.nCheck the values of the output matching network for Q102 andQ104, C258, L206, and C256. Look for open coils.nCheck the values of the bypass capacitors.nAs a last resort, replace the transistors, Q102 and Q104.Excessive Current DrainnIsolate different sections of the circuit; rf, audio, and digital.Look for reversed polarity capacitors or wrong resistor values.Deviation ProblemsnIf R149 cannot be adjusted to obtain the desired deviation, try to isolate the problem to the audio or rf section.nCheck the value of R149. To check the rf section, set the trans-mitter frequency to 800 MHz and verify that the tuning voltage ofthe VCO (U104, pin 5) is approximately 3 Vdc.
Shure UC1 Body-Pack UHF Transmitter2525A1043 (RI)Bench ChecksAudio ProblemsNo Tone KeyNo tone key means that the 32 kHz tone key sidebands are not visiblewhen the carrier is viewed on a spectrum analyzer. If tone key levels arethere but are too low, the deviation is off and needs to be recalibrated.nApply a 1 kHz tone at a level of 0 dBu to the audio input with the audio gain pot at minimum.nIf the carrier on the spectrum analyzer does not show any deviation, check part integrity and audio path continuity betweenU201, pin 1, and the VCO.nIf the spectrum analyzer shows a deviated carrier, probe for a 32 kHz signal at TP4 and I246 and continue to the next step.nIf there is a signal at I246 but not at TP4, then the mute circuitthrough Q4 or Q211 is being activated. Verify that the logic sig-nal at Q4 and Q211, pin 1, is logic low. If it is low, replace Q4 orQ211. If it is not low, check the line for a short to +5 V. If there isno short, the microprocessor is defective and must be replaced.nIf there is a 32 kHz signal at both I246 and TP4, replace R248.nIf there is not a 32 kHz signal at either I246 or TP4, there issomething wrong with the tone key circuit or the tone key supplyvoltage. If the tone key supply voltage (U201, pin 7) is less than2 V, there is a problem with one or more of the following com-ponents: R284, R287, R285, R286, C289, Q222, C222. R228.or R229..nIf the voltage at U201, pin 7, is greater than 2 V, the problem is inthe tone key circuit itself. Check for shorts and opens. Replaceparts in this circuit beginning with the crystal until the 32 kHz oscillation returns.No AudionView the carrier on the spectrum analyzer. If there are not 32 kHz tone key sidebands around the carrier, follow the stepsabove for “No Tone Key.”nIf there are tone key sidebands around the carrier, verify that thesignal generator is properly outputting signal.nVerify +9 V, half-supply bias, and ground connections to U2.nVerify +9 V, half-supply bias, and ground connections to U201.nFollow the audio path from where audio is applied until the pointof discontinuity is reached and replace the appropriate part.
Shure UC1 Body-Pack UHF Transmitter26 25A1043 (RI)NotesNotesThis page intentionally left blank.
Shure UC1 Body-Pack UHF Transmitter2725A1043 (RI)Replacement Parts and DrawingsReplacement Parts and DrawingsProduct ChangesSix versions of the UC1 and UC1L transmitters are available for usein various countries. Each version is identified below by country code,country designation, frequency range, and printed circuit board number.Parts DesignationsThe following comments apply to the parts list and the schematic:Resistors: Unless otherwise noted, all resistors are surface-mountwith 1/10 W rating and 1% tolerance.Capacitors: Unless otherwise noted, non-polarized capacitors aresurface-mount NPO dielectric types with a 100 V capacity and a 5% tolerance, and polarized capacitors are tantalum types.Table 4UC1 / UC1L Model Frequency Variations(in order by frequency)CountryCode CountryDesignation Frequency Range UC1 PrintedCircuit Board # UC1L PrintedCircuit Board #MC Netherlands 774 – 782 MHz 90MC8790H 90MC8791HUA U.S.A. and Canada 782 – 806 MHz 90UA8790H 90UA8791HJA Japan 797 – 806 MHz 90JA8790H 90JA8791HMB Europe 800 – 830 MHz 90MB8790H 90MB8791HJB Japan 806 – 810 MHz 90JB8790H 90JB8791HKK United Kingdom 838 – 862 MHz 90KK8790H 90KK8791HTable 5Replacement PartsReferenceDesignation Description Shure PartNumberMP1 Antenna 70A8015MP2 Belt clip 44A8013AMP3 Bushing 66A308MP4 Case back 65A8295AMP5 Case front 65A8294AMP6 Compression pad 36A8078MP7 Door 65A8296MP8 Foam pad 36A8073
Shure UC1 Body-Pack UHF Transmitter28 25A1043 (RI)Replacement Parts and DrawingsTable 6Printed Circuit Board ComponentsReferenceDesignation Description Shure PartNumberC123 Capacitor, trimmer, 5 – 40 pF 152F03C510 Capacitor, trimmer, 1.4 – 3.0 pF 152A04D101–104 Diode, dual switching, SOT-23 184A07D105, 206 Diode, signal / switching, SOT-23 184A08D201 LED, right angle, green 184F32D202 LED, right angle, yellow 184E32D203 LED, right angle, SMT, red 184D32D501 Diode, rf tuning 184A36J102 Jack, stereo, 35 mm 95A8774J201 Connector, receptacle 170A08J202,203 Battery contacts 56A8072AJ204 Connector, strip socket 170C15J301 Receptacle, male, 4-pin, TINI QG 95A8413J401 Connector, LEMO (UC1L) 95A8601P301,305 Connector, interconnect strip 56D8074Q1,4,211,215,216,218 Transistor, SOT-23, FET, TMOS 183A30Q101,213 Transistor, SOT-23, PNP 183A01Q102,501,502 Transistor 183A48Q103,105,217 Transistor, power, MOSFET 183A46Q104 Transistor, SOT-23 183A49Q201,202,204,219,220,221,222, 223Transistor, SOT-23, NPN 183A02R7 Potentiometer, gain 46H8014R149 Potentiometer, trim 146B02SW202 Switch, toggle, DPST 55A189SW203 Switch, slide 55A8087Y101 Crystal, 4 MHz 40A8012Y201 Crystal, 32.768 kHz 40A8010U2 IC, dual op amp 188A18U101 IC, microprocessor, programmed 188D238EU102 IC, EEPROM 188A131U103 IC, detector 188C210U104 IC, PLL frequency synthesizer 188A265U201 IC, quad op amp 188A49U203 IC, compander 188A126U205 IC, voltage regulator, 5 V 188A115U208 IC, quad comparator 188A123U501 Resonator, dielectric 140A14
Shure UC1 Body-Pack UHF Transmitter2925A1043 (RI)Replacement Parts and DrawingsTable 7Group Designators(in order by frequency)FrequencyRange(MHz)CountryDesignation CountryCode R27kΩR28kΩR29kΩR30κΩ R31kΩ774–782 Netherlands MC – – – – 1.0782–806 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 –CountryCode R34kΩR35kΩR36kΩR37kΩR38kΩR39kΩR41kΩMC – – – – – 1.0 –UA 1.0 – – – – – –JA,JB – – 1.0 – – – –MB – 1.0 – – – – –JB – – – 1.0 – – –KK – – – – 1.0 – –
Shure UC1 Body-Pack UHF Transmitter30 25A1043 (RI)Replacement Parts and DrawingsTable 8Frequency Dependent Components(in order by frequency)FrequencyRange (MHz) CountryDesignation CountryCode C7pF C8uF C12pF C117pF C118pF C173pF C215uF774–782 Netherlands MC 0.047 0.1 100 – – 27 2.2782–806 US & Canada UA – – – 27 –797–806 Japan JA 0.047 0.1 100 27 27 – 2.2800–830 Europe MB 0.047 0.1 100 – – 27 2.2806–810 Japan JB – – – 27 27 – –838–862 England KK 0.047 0.1 100 – – 27 2.2CountryCode C216uF C505pF C506pF C509pF J103 Q2 Q3 R1kΩR2kΩR3kΩMC – 3.3 3.3 1.8 – 183A01 183A02 10 1.5 249UA 0.047 4.7 4.7 1.8 – – – – 0 4.99JA – 4.7 4.7 1.8 170A14 183A01 183A02 10 10 249MB – 4.7 4.7 1.8 – 183A01 183A02 10 1.5 249JB 0.047 4.7 4.7 1.8 170A14 – – – 0 4.99KK – – – – – 183A01 183A02 10 1.5 249CountryCode R9kΩR11kΩR12kΩR13kΩR14κΩ R15kΩR16MΩR17MΩR18kΩR25kΩR26kΩMC – 100 100 40.2 100 10 1.0 1.0 22.1 – –UA 0 – – – – – – – – 0 1.0JA – 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 0––––––––0–KK – 100 100 40.2 100 10 1.0 1.0 22.1 – –CountryCode R27kΩR28kΩR29kΩR30kΩR34kΩR35kΩR36kΩR37kΩR38kΩR133kΩMC 1.0 – – – – – – – – 22.1UA – – – – 1.0 – – – – 22.1JA – 1.0 – – – – 1.0 – – 150MB 1.0 – – – – 1.0 – – – 22.1JB – – 1.0 – – – – 1.0 – 150KK – – – 1.0 – – – – 1.0 22.1CountryCode R1441 kΩR286kΩR287kΩR298kΩS101GRP S102CH U1 Y102 Y103MC – 200 24.9 – 155B11 155A11 183A136 – 140C15UA – 200 24.9 4.02 155B11 155A11 – – 140C15JA 146B02 24.9 – – 155A11 155B11 183A136 40A8012 –MB – 200 24.9 – 155B11 155A11 183A136 – 140C15JB 146B02 24.9 – 4.02 155B11 155A11 – 40A8012 –KK – 200 24.9 – 155B11 155A11 183A136 – 140C15
Shure UC1 Body-Pack UHF Transmitter3125A1043 (RI)Replacement Parts and DrawingsUC1 Body-Pack TransmitterAudio–Rf Printed Circuit BoardSide 1
Shure UC1 Body-Pack UHF Transmitter32 25A1043 (RI)Replacement Parts and DrawingsUC1 Body-Pack TransmitterAudio–Rf Printed Circuit BoardSide 2

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