Shure_UC1_Wireless_Transmitter_Service_Manual 电路图.pdf

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1、SERVICE MANUAL CHANGE NOTICE UC1 UHF BODY-PACK TRANSMITTER Changes or corrections have been made to this service manual. Update your service manual by replacing the pages listed in the table below with the ones attached to this change notice. CHANGES EFFECTIVE DATE REMOVE these pages from your curre

2、nt manual INSERT the following revised pages attached to this notice Revision 1 ALLRevision 2 ALL Revision 2 pages:13,15,17,20,22,27,29 and 30Revision 3 pages:13,15,17,20,22,27,29 and 30 SERVICE MANUAL REVISION HISTORY ReleasePart NumberDate Code Original25A1043RI Revision 125B1043SB Revision 225C10

3、43TB Revision 325C1043TK Shure Incorporated 222 Hartrey Avenue Evanston IL 60202-3696 U.S.A. UC UHF Wireless System ?1999, Shure Incorporated Printed in U.S.A. RadioFans.CN 收音机爱 好者资料库 ?2000, Shure IncorporatedPrinted in U.S.A. 25C1043 (TK) Service Manual 25C1043 (TK) UC1 / UC1L Body-Pack Transmitter

4、 Characteristics General The Shure UC1/UC1L Body-Pack Transmitter is microprocessor- controlled, operating in the 692716 MHz and 774862 MHz frequency ranges. The UC1/ UC1L is used in mid-level installed sound, rental, and concert sound applications. Six frequency range variations are available. Cont

5、rols and Connectors 1 2 3 1.Antenna 2.Power/Battery Fuel Gauge LEDs 3.Power ON/OFF Switch 4.Input Connector 5.Rf/Audio Mute Switch Input Connector 6.Input Attenuation Control 7.Audio Gain Control 8.Group Rotary Switch 9.Channel Rotary Switch 10. Battery Compartment 11. Battery Cover Release Tabs 12.

6、 Battery Compartment Cover Figure 1.UC1 Controls and Connectors 4 5 10 11 12 7 8 9 6 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. Licensing: Operation may require a user

7、 license. Frequency or power-output modifications may violate this products approvals. Contact your countrys communications authorities. RadioFans.CN 收音机爱 好者资料库 Shure UC1 Body-Pack UHF Transmitter 2 Circuit Description25C1043 (TK) Circuit Description CONTROL PLL CONTROL MCU EEPROM (MEM) OFF / MUTE D

8、ETECT +5V REG. REMOTE MUTE GROUPCHANNEL SYNTH. RF POWER RF MUTERF MUTE VCO FROM BATT. UNREG. PWR. +5v AUDIO IN PWR. HOLD CIRCUIT MIC. / INSTR. ON / OFF SWITCH FET BYPASS TONE KEY CIRCUIT TONE CONTROL TONE KEY CALL IDBATTERY MGMT. different VCOs are required for MB and KK frequen- cy models. At the o

9、utput 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 synthe- sizer divides the signal, as necessary, to the desired reference frequency of 125 kHz. The synthesizer c

10、ontains a reference oscillator circuit oper- ating 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

11、 made via microprocessor U101, which inter- faces 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 s

12、ignal 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 throug

13、h 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 c

14、ouples 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 u

15、sed 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 50 antenna. During transmit

16、ter 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 attenu- ation until the PLL has locked. Shure UC1 Body-Pack UHF Transmitter 5Circuit Description 25C1043 (TK) The transmitter is

17、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.

18、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

19、 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, thi

20、s 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 microcontrol

21、ler 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

22、 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 sto

23、res the mapping of compatible groups and channels. The microcontroller serially communicates with this part via data and clock lines to read the frequen- cy corresponding to the group and channel position. Ability to write to this memory occurs during factory programming only. During normal usage, t

24、his 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 driven independently of the microcontroller port pin states during in-circuit programming of EEPROM. Shure U

25、C1 Body-Pack UHF Transmitter 6 Circuit Description25C1043 (TK) Battery Management Section The microcontroller provides for low battery shutdown. The shut- down threshold is 1.88 Vdc 10%. A voltage lower than the shutdown threshold on pin 17 of the U101 microcontroller shuts down the transmit- ter. R

26、esistors 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 cur- rent draw from

27、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 swit

28、ch, 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 throug

29、h R112 are the pull-ups for the switch position read. Diode packs D101 through D104 isolate the switches dur- ing 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

30、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

31、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 chan

32、ge is made by a state toggle from odd to even, or vice 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 selectively grounded outputs to read the selected switchs state on pins 3 through 6. A multiplexed switch read is prec

33、eded by tone key and rf mutes. This mutes the audio in the receiver to allow a quiet change to another frequency. Shure UC1 Body-Pack UHF Transmitter 7Circuit Description 25C1043 (TK) Power Switch and Remote Mute Switch Interface When a transmitter is turned off, the PWRDN1 signal goes to logic low

34、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 auto- matically kicks in to bypass the powe

35、r 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. PW

36、RDN1 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

37、 immediately mutes the audio. Shure UC1 Body-Pack UHF Transmitter 8 Circuit Description25C1043 (TK) Notes This page intentionally left blank. Shure UC1 Body-Pack UHF Transmitter 9Disassembly 25C1043 (TK) Functional Test Verify operation and reported malfunction, referring to the product User Guide f

38、or 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

39、.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 Shure UC1 Body-Pack UHF Transmitter 10 Reassembly2

40、5C1043 (TK) 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 dis

41、assembly steps in reverse order. Shure UC1 Body-Pack UHF Transmitter 11Test Equipment Set-Up 25C1043 (TK) 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 measurem

42、ent. 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 Test Equipment Most test equipment needed is described in the Shure Wireless Servi

43、ce Equipment Manual. The following test equipment (or approved equivalent) is also needed. Table 1 Test Equipment Equipment TypeModel Audio analyzer*Hewlett-Packard 8903B Digital multimeterFluke 87 PCB interconnect cablePT1843 Japan Version Test CablePT1838AF Japan Version Test ConnectorPT1838AJ Fre

44、quency counterHewlett-Packard 53181A Rf signal generatorHewlett-Packard 8656B Spectrum analyzerHewlett-Packard 8590L Shure UC4 receiverShure UC4 BNC(male) to unterminated 50? test cable PT1824 *Audio levels in dBu are marked as dBm on the HP8903B. Test Equipment Set-Up The alignment procedure is seq

45、uential and does not change, unless specified. 1.Use PT1824 cable for all RF connections. except for the Japan frequencies, use PT1838AF/AJ test adapter / cable. 2.Keep the test cables as short as possible (less than 12 inches). Shure UC1 Body-Pack UHF Transmitter 12 Test Set-Up25C1043 (TK) 3.Includ

46、e 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. Test Set-Up R7 SW203 PAD C225 C223 C257 C256 C219 SIDE 1 W101 TP107 TP106 TP110 TP102 TP103 GND U701 U108 Q104 L

47、115 Y103 U501 C130 TP131 TP5 C123 S102 S101 TP108 TP109 J203 J202C119 C510 TP130 TP111 + 5V + 9V TP120TP104 TP7 GREEN RED R149 L208 J204 U203 U201 U208 STR1 C246 Q219 Q221 Q1 Q222 U1 U2 D206 Q2 TPMIC1 C203 C208 Q3 Q223 Q204 Q201Q202 A EG C B D F H TBIAS1 TP3 TPA1 TP1 TP9 TP13 TP19 TP12 TP14 TPGND1 T

48、PAUD1 TP4 L205 Q215Q216 Q220 TP8 TP6 TP10 + 9V TP239 TP18 TP+5 TP17 TP16 SIDE 2 TBIAS1 TP1 J301 SW202 D203 D202 D201 Y201 TP4 TP239 TPGND1 TPAUD1 C240 Q4 C220 C255 TP3 B D CA F H GE TPMIC1 TPA1 J201 U205 Q213 Q217 TP18 TP+5 TP9 TP21 TP16 + 9V TP14 TP12 TP19 TP13 TP7 TP6 TP17 TP10 TP8 TP2 C206 Q218 J

49、202 J401 U106 J101 Y102 4.000 U102 PAD U109 U107 U104 Q103 Q105 C176 Q101 D102 D103D101 C176 D104 Y101 4.000 D105 TP130 TP5 U103 TP111 TP104 TP120 + 5V + 9V TP102 TP103 TP110 TP106 TP107 W101 TP108 TP109 + 9 Vdc VCO TP2 TP21 *J103 *R144 *R144 and J103 are for JA, JB frequencies only. Figure 4.UC1 Major Test Component Locations 1.Remove the U1 antennas. 2.The attenuator switch (SW203) must be in the 0 dB position. 3.Use the PT1843 cable to connect the RF-digital board and the audio board through the 11-pin board interconnects (J101, J201, side 2). 4.Apply +9 Vdc across the bat