shure_t_2 电路图.pdf

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1、Shure Incorporated 222 Hartrey Avenue Evanston IL 60202-3696 U.S.A. T Wireless System ?1999, Shure Incorporated Printed in U.S.A. 2510181 (CC) SERVICE MANUAL CHANGE NOTICE T2 WIRELESS HANDHELD TRANSMITTER Changes and corrections have been made to the Service Manual for the T2 handheld Transmitter. T

2、o update your Service Manual, remove the pages identified in the tables below and replace them with the pages at- tached to this Change Notice. Note that there are no changes to pages not specifically identified in the tables below. T2 HANDHELD TRANSMITTER SERVICE MANUAL REVISION HISTORY ReleasePart

3、 NumberDate CodeColor Original25A1018QHWhite Revision 125B1018SBPink Revision 225C1018SIWhite Revision 325C1018TFWhite Revision 425C1018TLWhite Revision 525C1018AFWhite Revision 625C1018BAWhite Revision 725C1018CCRed CHANGES EFFECTIVE MARCH 17, 2003 REMOVE these pages from Revision the T2 Service Ma

4、nual INSERT these new Revision pages into the T2 Service Manual 31 there are no separate label plates. (c)As you slide out the transmitter subassembly (audio, RF, and head circuit boards) from the handle, note how it was positioned in the internal guides. bezel tabhandle tab circuit-board subassembl

5、y (Right-side view) Figure 2.Removing the Bezel Shure T2 Vocal Artist Microphone Transmitter 10Disassembly and Assembly25C1018 (CC) Reassembly 1.Insert the transmitter subassembly (audio, RF, and head circuit boards) into the internal guides of the handle (Figure 3). 2.Orient the retaining ring so i

6、ts gap will fit over the flat edge of the head board (to avoid shorting the board). Use snap-ring pliers to insert the retaining ring into the groove inside the handle. 3.Drop in the switch actuators and position the label plate (older bezels only) over them. Position the bezel over the switches the

7、n press until it snaps into place. 4.Screw on the microphone cartridge and ball screen. Install a bat- tery (if desired) and screw on the battery cup. A AA ball screen microphone cartridge SM 58 retaining ring bezel label plate (older bezels only) switch actuators 9 V alkaline battery battery cup ba

8、ll screen microphone cartridge BG 3.1 circuit- board guides head board switches audio circuit- board gain control RF circuit- board handle access to gain control (older, BG 3.0 cartridge) Figure 3. Shure T2 Vocal Artist Microphone Transmitter 11Service Procedures25C1018 (CC) Service Procedures Refer

9、ence Material The Shure Wireless System T Series Users Guide describes the product, tells how to operate it, and provides troubleshooting and techni- cal data. Special Equipment and Tools In addition to the standard items described in the Wireless Service Equipment manual, you will need: ?to verify

10、that the system is working properly, obtain the receiver with which the transmitter is used (usually a T3 or T4); other- wise, use the modified SC4 receiver described in the equipment manual ?a small flat-blade screwdriver to remove the bezel ?snap-ring pliers to remove and re-insert the retaining r

11、ing ?hand-made high-impedance probe (see the Service Equipment manual) System Operating Frequencies Each transmitter circuit board is marked with a group letter that iden- tifies the range of frequencies on which the transmitter can operate. Note that Table 1 applies only to T2 transmitters that are

12、 FCC-approved, and Table 2 applies only to T2 transmitters that are ETSI-approved. Frequency Coverage: Earlier models used the same family of RF boards (with Groups A, B, and C) for all the frequencies offered world- wide at that time. Now there are separate board assemblies for units ap- proved by

13、the ETSI. If you have a frequency from Table 4, you have an ETSI-approved model; if you have a frequency from Table 3, you have an FCC-approved model. Table 1 Pc Board Groups for FCC-Approved Models GroupFrequency Range A169.000183.975 MHz B184.000198.975 MHz C199.000215.975 MHz Used with pcb assemb

14、ly 90_8690 (pcb marking 34A8494). Shure T2 Vocal Artist Microphone Transmitter 12Service Procedures25C1018 (CC) Table 2 Pc Board Groups for ETSI-Approved Models GroupFrequency Range A169.000173.975 MHz B174.000180.975 MHz C181.000187.975 MHz D188.000194.975 MHz E195.000201.975 MHz F202.000208.975 MH

15、z G209.000215.975 MHz H216.000222.975 MHz K216.000239.975 Used with pcb assembly 90_8705 (pcb marking 34A8538). Tables 3 and 4 provide information for identifying the system fre- quency. The Crystal Letter Code, when used with the appropriate Shure model number, identifies a specific operating frequ

16、ency for both transmit- ters and receivers. Note that, although a Crystal Letter Code always des- ignates a specific frequency, it may be used with different Group Letters on other products. Table 3 T2 System Operating Frequencies for FCC-Approved Models Group Crystal Code Operating Freq. (MHz) AV16

17、9.445 AW171.845 ACA176.200 ACC177.600 ACE182.200 ACF183.600 BCG186.200 BCL192.200 CCQ202.200 CCV208.200 Used with pcb assembly 90_8690 (pcb marking 34A8494). Shure T2 Vocal Artist Microphone Transmitter 13Service Procedures25C1018 (CC) Table 4 T2 System Operating Frequencies for ETSI-Approved Models

18、 Group Crystal Code Operating Freq. (MHz) AAQ173.800 BZZ174.500 BBB175.000 BNB175.000 BND176.600 BNE177.600 CNH182.000 CNK183.600 CNL184.600 CS184.000 DNP189.000 DNR190.600 ENX197.600 ENY198.600 ENZ200.350 EPU201.650 FPB203.000 FPD204.600 HPP217.000 HPR218.600 HPS219.600 KPV232.825 KPX233.125 KPY234

19、.625 KPZ237.325 Used with pcb assembly 90_8705 (pcb marking 34A8538). Changing the Frequency The operating frequency of the T2 transmitter may be changed with- in a specific Group by changing the crystal on the pc board. (For Group information, see the preceding subsection). Check the transmitter fo

20、r proper operation before changing its operating frequency. After installing the new crystal, perform the alignment procedures. Then run an opera- tional test to ensure that the transmitter is functioning properly. Finally, update the label to show the new frequency and letter identification code. S

21、hure T2 Vocal Artist Microphone Transmitter 14Service Procedures25C1018 (CC) Note: To ensure proper operation, obtain the crystal from Shure and verify that it operates within the frequency range of the pc board. Since crystals are marked with the nominal oscillating frequency, not with a letter cod

22、e, you can use the following equation to determine the frequency at which a transmitter will operate with a given crystal: Carrier Frequency = (9 x nominal crystal freq. in MHz) .09 FCC- and ETSI-Approved Models To accommodate the different frequencies and requirements, Shure supplies the T2 with di

23、fferent RF boards for FCC-approved models (used in North America and other places) and ETSI-approved models (used in Europe and other places). Although the RF alignment procedures are similar for the two boards, there are some differences, especially in the number of tuning stages and in the numberi

24、ng of components and test points. The audio-alignment procedures are the same for both versions of the T2. Note: Before the introduction of a distinct RF board for ETSI 300 922 requirements, all units shared the same RF and audio boards. Drawings for Different Versions At the back of this manual are

25、 diagrams of the circuit boards and schematics for the original versions of the audio and RF boards as well as for the current versions of the audio board, FCC-approved RF board, and ETSI-approved RF board. Refer to the circuit-board diagrams for the test points. Alignment The RF and audio alignment

26、s are generally done together, as a single, continuous procedure. Before beginning, do the setup described in the following subsection, “Test Conditions.” Unless specified for FCC- or ETSI-approved models, the alignment procedures apply to all models. Test Conditions The following test conditions ap

27、ply to all versions unless otherwise specified: ?An external 9-volt supply is connected to the battery terminals (J101 and J102). ?The Gain pot (R125) is set to its mid-range position. ?The audio analyzers 400 Hz high-pass and 30 kHz low-pass filters are pressed in. FCC-Approved Units 1.Obtain a 50

28、test cable for connecting the circuit boards to vari- ous test equipment. (To construct this cable, see “50 Test Cable Assembly” in the Wireless Service Equipment manual.) Shure T2 Vocal Artist Microphone Transmitter 15Service Procedures25C1018 (CC) 2.Tack-solder the cable to side 1 of the RF circui

29、t board as follows: ?Center conductor to the 50 solder pad, I210 ?Shielding to I2GN (on older versions, IGND) ETSI-Approved Units 1.Obtain a 50 coaxial test cable for connecting the circuit boards to various test equipment. (To construct this cable, see “50 Test Cable Assembly” in the Wireless Servi

30、ce Equipment manu- al.) 2.Tack-solder the cable to the bottom of the RF circuit board as fol- lows: ?Center conductor to the 50 solder pad, TP6 ?Shielding to TP7 (ground) High-Impedance Probe for TP5: When measuring test point 5, fashion a high-impedance probe on the end of the test cable by connect

31、- ing a 50 resistor between the center conductor and the shield, and a 0.5 pF capacitor to the end of the center conductor (see the following illustration). 50 0.5 pF shield Figure 4.High-Impedance Probe for ETSI-Approved Models All Units 3.Carefully remove C240 (domestic units) or C242 (ETSI units)

32、 from the RF board. Note: This disconnects the battery antenna to allow accurate conductive-power measurements. Display Checks 1.Connect the 9 Vdc power supply to the audio board: the positive lead to I140 (the positive battery terminal), and the negative lead to I145 (ground). 2.Slide S101 (Power)

33、to “On” (toward the board number), and S102 (Mic) to “Off” (away from S101): the green LED should glow. If it doesnt, there is a circuit malfunction. 3.Reduce the power-supply voltage to 6 Vdc: the red LED should glow. 4.Return the power supply voltage to 9 Vdc. Shure T2 Vocal Artist Microphone Tran

34、smitter 16Service Procedures25C1018 (CC) + R130 U101 U102 J101 J102 + R125 J101 J102 L209R217 Y201C217C216 +9 V +9 V +5 V +9 V Audio Board (top) Low battery (red) D101 Power (green) D103 Head Board (front view) FCC-Approved Model RF Board (top) + J101 J102 Y201 ETSI-Approved Model RF Board (top) L20

35、1R201C214C222C226 Gold-plated contacts C216 Power On/Off S101 Mic On/Off S102 Audio In (from audio board) Gnd GndGnd Audio Out (to RF board) Audio In (from cartridge) +9 V (to cartridge) Audio In (to audio board) IGnd I210 TP6 TP7 + C107 TP5 (base of Q202) Figure 5.Major Components Referred to in th

36、e Alignment Procedures Shure T2 Vocal Artist Microphone Transmitter 17Service Procedures25C1018 (CC) RF Alignment: FCC-Approved Models Do not apply modulation during the following RF alignment proce- dures. Note: If you cannot achieve any of the settings described in these procedures, see “Bench Che

37、cks,” starting on page 23. 1.Make sure that the Mic switch (S102) is turned to ”Off.” 2.On the spectrum analyzer, set the center frequency to the fre- quency of the T2. Then make the following settings: ?Span: 1 MHz ?Reference level: +20 dBm ?Scale: 10 dB/div. 3.Connect the 50 output cable to the sp

38、ectrum analyzer. A: Output Power (FCC-Approved Models) 1.With a yellow Toray non-conductive tuning tool, adjust C217 and C216 for maximum (peak) output power on the spectrum analyz- er. If the signal is very near the top of the screen, switch the scale to 2 dB/div. 2.The output power should be 15 dB

39、m, 2 dBm (compensate for cable losses in this calculation). B: Frequency Adjustment (FCC-Approved Models) 1.Connect the 50 output cable to the frequency counter through the 20 dB attenuator. With a pink Toray driver, adjust L209 to set the RF carrier frequency to the operating frequency (1 kHzsee Ta

40、ble 3 on page 12). 2.Reconnect the 50 output cable to the spectrum analyzer. Con- firm that the output power remains within specification. If not, readjust C217 and C216 as described in the preceding “Output Power” subsection. C: Spurious Emissions (FCC-Approved Models) 1.Set the spectrum analyzer a

41、s follows: ?Scale: 10 dB/div ?Start Frequency: 10 MHz ?Stop Frequency:1 GHz ?Reference level: 20 dBm 2.Check the level of spurious emissions: All must be at least 30 dB below the carrier level. If necessary, retune C217 and C216. Shure T2 Vocal Artist Microphone Transmitter 18Service Procedures25C10

42、18 (CC) D: Current Drain (FCC-Approved Models) 1.With a digital multimeter, measure the current drain of the trans- mitter: it should be less than 35 mA. If it is too high, try detuning C216, but make sure that the power and spurious response re- main within specification. 2.Check for 9 Vdc (0.35 Vd

43、c) at +9 V on the head board (I133 on the audio board). RF Alignment: ETSI-Approved Models Do not apply modulation during the RF alignment procedures. Note: If you cannot achieve any of the settings described in these procedures, see “Bench Checks,” starting on page 23. 1.Slide the Mic switch (S102)

44、 to the ”Off” position. 2.On the spectrum analyzer, set the center frequency to one-third the frequency of the T2. Then make the following settings: ?Span: 30 MHz ?Reference level: +20 dBm ?Scale: 10 dB/div. 3.Connect the high-impedance probe to the spectrum analyzer. A: Output Power (ETSI-Approved

45、Models) 1.Connect the high-impedance probe to TP5 (the base of Q202). 2.With a yellow Toray non-conductive screwdriver, adjust C214 for maximum (peak) output power on the spectrum analyzer. For better resolution while tuning, switch the scale to 2 dB/div and adjust the reference level to the center

46、of the screen. 3.Remove the high-impedance probe. Connect the standard 50 output cable to TP6 (before antenna-matching). 4.Plug the BNC end of the 50 cable into the spectrum analyzer. 5.Set the center frequency to the frequency of the T2. 6.Adjust C216 and C222 for maximum (peak) output power on the

47、 spectrum analyzer. Note: C216 is not tuneable on earlier ETSI-approved units. B: Frequency and Final Output Power (ETSI-Approved Models) 1.Connect the 50 output cable to the frequency counter. With a pink Toray driver, adjust L201 to set the RF carrier frequency to within 1 kHz of the operating fre

48、quency (see Table 4, page 13). 2.Reconnect the 50 output cable to the spectrum analyzer. Peak C226 for maximum output power on the spectrum analyzer. 3.Confirm that the output power is 9.5 dBm (2 dBm). Shure T2 Vocal Artist Microphone Transmitter 19Service Procedures25C1018 (CC) C: Spurious Emission

49、s (ETSI-Approved Models) 1.Set the spectrum analyzer as follows: ?Scale: 10 dB/div ?Start Frequency: 10 MHz ?Stop Frequency:1 GHz ?Reference level: 20 dBm 2.Check the level of spurious emissions: All must be at least 44 dB below the carrier level. If necessary, retune C226. D: Current Drain (ETSI-Approved Models) 1.With a digital multimeter, measure the current drain of the trans- mitter: it should be less than 35 mA. If it is too high, try detuning C226, but make sure that the power