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Shure U4D Dual Diversity UHF Receiver

21

25D1062 (AG)

Service Procedures

Rf Tuning, Channel A

Dc Voltage Verification

C227

C242

P202

P202

P203

S201

ANTENNA A IN

P202

P202

P203

S201

ANTENNA B IN

DC VOLTMETER

DC VOLTMETER

(OFF)

(OFF)

J302

Figure 5.

Dc Voltage Level Verification

1. Measure the dc voltage between the center pin of BNC 

connector ANTENNA A IN, located on the receiver rear panel,
and ground. The voltage should measure 12.0 

±

0.5 Vdc.

2. Measure the dc voltage between the center pin of BNC 

connector ANTENNA B IN, located on the receiver rear panel
and ground. The voltage should measure 12.0 

±

0.5 Vdc.

Содержание U4D

Страница 1: ...rs To update your Service Manual remove the pages identified in the tables below and replace them with the pages attached to this Change Notice Note that there are no changes to pages not specifically...

Страница 2: ...AUDIO Level Indicators 5 Programmable Display 6 Button 7 Button 8 Volume Control 9 Headphone Monitor Volume Control 10 Headphone Monitor Status 11 Headphone Input Connector 12 POWER On Off Switch 13...

Страница 3: ...B is connected to J302 of receiver 2 Connectors J302 on each receiver are the input of the rf power dividers Each of these splits the rf power from the antenna between two receivers The outputs of th...

Страница 4: ...tal board includes a user controlled microprocessor that allows users to change the frequency and other settings Audio Section The audio for channel A comes from the channel A detector output of the r...

Страница 5: ...The third path goes into the compandor via a 17 kHz low pass filter Here the audio is expanded and de emphasized The compandor output then goes off the audio board to a volume potentiometer on the fro...

Страница 6: ...levision channel The LCD also has a battery fuel gauge that indicates the state of the transmitter battery A padlock icon on indicates whether the user accessible menus are locked or unlocked A 4 000...

Страница 7: ...the 5 LED bar graph formed by D117 D115 D110 D109 and D105 Channel B Bar graph driver U102 gets the DRSSI_CH_B analog signal U102 5 P102 11 I170 from the rf audio board and indicates its strength on...

Страница 8: ...DLE Data Load Enable to U309 PLL Synthesizer 6 DRSSI_CH_A Chan A rf Received Signal Strength Indicator 7 DD Data signal to U309 PLL Synthesizer 8 DLEDA Diversity LED A drive signal input 9 DCK Clock...

Страница 9: ...Shure U4D Dual Diversity UHF Receiver 8 25D1062 AG Notes Notes This page intentionally left blank...

Страница 10: ...Shure U4D Dual Diversity UHF Receiver 9 25D1062 AG Preliminary Tests Preliminary Tests Test Component Locations Rf Audio Board Side 1...

Страница 11: ...Shure U4D Dual Diversity UHF Receiver 10 25D1062 AG Preliminary Tests Audio Rf Board Side 2...

Страница 12: ...1 Remove five screws and washers from the top of the receiver and two screws and washers from the left and right sides of the receiver Lift off the top cover 2 Program the receiver squelch through th...

Страница 13: ...rom the outside of the receiver and is marked HIGH Z With the audio analyzer NOT in the Float position the audio voltage at unbalanced audio output J209 pin 1 and 2 unloaded should be as follows UA UB...

Страница 14: ...om tip over 12 UNPLUG this apparatus during lightning storms or when unused for long periods of time 13 REFER all servicing to qualified service person nel Servicing is required when the apparatus has...

Страница 15: ...assis 3 Tag and disconnect the power on off switch from the power supply wires 4 Remove the rubber monitor volume control knob and the master volume control knob by pulling them away from the front pa...

Страница 16: ...e monitor board away from the chassis Power Supply Removal 1 Tag and disconnect the cables attached to the power supply 2 Remove the screws and washers that secure the power supply to the receiver cha...

Страница 17: ...ON OFF SWITCH ANTENNA A ANTENNA B RECEIVER 1 AC POWER INPUT DUAL RF LO DUAL RF LO DUAL BNC REAR TO NET BOARD TO MONITOR BOARD J203 J216 DUAL BNC REAR DUAL RF LO DUAL RF LO RECEIVER 2 TO DISPLAY BOARD...

Страница 18: ...ed with any revision rf audio board On newer boards the switches will be surface mount components on older boards the switches are thru hole components PRINTED CIRCUIT BOARD REVISION RUBBER ACTUATOR P...

Страница 19: ...ent Type Model Audio analyzer Hewlett Packard 8903B Digital multimeter Fluke 87 Rf signal generator HP 8656B or E440B Frequency counter Hewlett Packard 53181A Spectrum analyzer HP 8590L or E4403B Shur...

Страница 20: ...t any components in the receiver switching power supply The heat sink on the power supply and all ac wiring contains hazardous voltages 3 Dc voltages are present at most rf test points Use dc blocks o...

Страница 21: ...or 6 Set the audio analyzer output for 1 kHz and 1 4 V 5 2 dBu 7 Adjust the audio analyzer output amplitude until both the HI EXT and LO EXT lights on the rf generator turn off use amplitude increment...

Страница 22: ...METER DC VOLTMETER OFF OFF J302 Figure 5 Dc Voltage Level Verification 1 Measure the dc voltage between the center pin of BNC connector ANTENNA A IN located on the receiver rear panel and ground The v...

Страница 23: ...NA B IN CH 2 FREQUENCY COUNTER VC101 CH 1 OFF OFF J302 Figure 6 Local Oscillator Frequency Alignment If using a spectrum analyzer adjust the span so that the frequency accuracy measurement is better t...

Страница 24: ...gnment Connections 1 Set the rf signal generator Frequency to Fo Set the Level to 86 dBm and verify the Deviation as follows UA UB MA MB MC MD 45 kHz deviation at 1 kHz modulation KK 40 kHz deviation...

Страница 25: ...NNA B IN U303 U315 DC VOLTMETER PIN 8 PIN 17 DC BLOCK NOTE DC VOLTAGES ARE PRESENT AT MOST RF TEST POINTS USE A DC BLOCK ON THE RF SIGNAL GENERATOR TO PROTECT TEST EQUIPMENT OFF OFF J302 Figure 8 Chan...

Страница 26: ...T EQUIPMENT DC BLOCK OFF OFF J302 L310 for PCB 34A8507 L311 for PCB 34A8703 Figure 9 Channel A RSSI Alignment 1 Change the rf signal generator Level to 50 dBm 2 Measure the total harmonic distortion T...

Страница 27: ...GNAL GENERATOR TO PROTECT TEST EQUIPMENT OFF OFF J302 Figure 10 Channel A Noise Setup Connections 1 Set the modulating frequency from the audio analyzer to 60 kHz and if necessary readjust the amplitu...

Страница 28: ...Channel B FM Detector Quadrature Coil Alignment 1 Set the rf signal generator Level to 86 dBm and the Deviation as follows If necessary readjust the amplitude so HI EXT and LO EXT lights turn off UA U...

Страница 29: ...S201 PIN 8 PIN 17 RF SIGNAL GENERATOR DC BLOCK NOTE DC VOLTAGES ARE PRESENT AT MOST RF TEST POINTS USE A DC BLOCK ON THE RF SIGNAL GENERATOR TO PROTECT TEST EQUIPMENT OFF OFF J302 Figure 12 Channel B...

Страница 30: ...IPMENT OFF OFF J302 L304 for PCB 34A8507 FL313 for PCB 34A8703 Figure 13 Channel B RSSI Alignment Connections 1 Change the rf signal generator level to 50 dBm 2 Measure the total harmonic distortion T...

Страница 31: ...A DC BLOCK ON THE RF SIGNAL GENERATOR TO PROTECT TEST EQUIPMENT OFF OFF J302 Figure 14 Channel B Noise Setup Connections 1 Set the modulating frequency from the audio analyzer to 60 kHz and if necess...

Страница 32: ...iation set to 45 kHz If necessary readjust the amplitude so that the HI EXT and LO EXT lights turn off 2 Place the terminal of the audio analyzer on U207 pin 7 and connect the terminal to ground 3 Adj...

Страница 33: ...eads 0 436 0 005 Vrms 5 Disconnect the rf signal generator from the BNC connector ANTENNA A IN on the receiver back panel II Models Japan 1 Set the rf signal generator deviation to 28 kHz and modulati...

Страница 34: ...17 Tone Key Filter Alignment Connections For the following test make sure the tone key switch S201 is ON 1 Turn the tone key switch S201 to the ON position 2 Turn the rf signal generator output OFF 3...

Страница 35: ...Alignment The Receiver 2 alignment procedure is identical to the Receiver 1 alignment procedure However for the Receiver 2 alignment procedure refer to Antenna B alignment procedures each time Antenn...

Страница 36: ...R78902 R2 800 830 MHz Europe 90R28902 MC 774 782 MHz Netherlands 90MC8902 R3 774 782 MHz Netherlands 90R38902 MD To create an MD board order the 90MB8902 PCB and install the MD EEPROM 188R131MD II 806...

Страница 37: ...8901 A16 Printed circuit board assembly monitor 90A8635G A17 Printed circuit board assembly network 90A8629C A18 Wire assembly 90A8682 MP1 Actuator pair J or earlier board versions 66A8039 MP2 Actuato...

Страница 38: ...0 Potentiometer 10k 46A8069 U105 Dot Bar display driver 86A8941 Table 6 Digital Display Printed Circuit Board Replacement Parts SMT Components Side 1 Reference Designation Description Shure Part Numbe...

Страница 39: ...C238 Electrolytic capacitor 10 F x 80 V 86AS629 C243 247 Electrolytic capacitor 47 F x 63 V 86BE629 FL301 305 306 307 308 309 319 320 Ceramic filter 86A8971 FL304 312 Saw filter 80A8195 J203 216 Heade...

Страница 40: ...ometer SMD Trim 146B02 R355 367 Potentiometer SMD Trim 146D02 U201 202 204 205 207 210 212 213 216 220 305 310 Dual Op Amp 188A18 U203 208 Comparator SMD quad 188A123 U206 Compander low voltage 188A12...

Страница 41: ...62 AG Replacement Parts and Drawings Table 13 VCO Selection Country Code UA205 VCO Range Shure Part Number UA MA MC 824 849 MHz 187A04 KK S2 837 863 MHz 187B04 MB MD R2 800 830 MHz 187C04 UB M3 R6 692...

Страница 42: ...Shure U4D Dual Diversity UHF Receiver 41 25D1062 AG Replacement Parts and Drawings SIDE 1 SIDE 2 Figure 18 Digital Display Printed Circuit Board Legend...

Страница 43: ...Shure U4D Dual Diversity UHF Receiver 42 25D1062 AG Replacement Parts and Drawings Figure 19 Headphone Monitor Printed Circuit Board Legend...

Страница 44: ...Shure U4D Dual Diversity UHF Receiver 43 25D1062 AG Replacement Parts and Drawings SIDE 1 SIDE 2 Figure 20 Network Interface Printed Circuit Board Legend...

Страница 45: ...Shure U4D Dual Diversity UHF Receiver 44 25D1062 AG Notes Notes This page intentionally left blank...

Страница 46: ...Shure U4 UHF Diversity Receiver 25D1062 TL 45 U4 Rf Audio Printed Circuit Board Legend Side 1...

Страница 47: ...Shure U4 Diversity UHF Receiver 46 25D1062 TL U4 Rf Audio Printed Circuit Board Legend Side 2...

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