IC-V8000_SM.pdf

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1、SERVICE MANUAL VHF FM TRANSCEIVER 1-1-32, Kamiminami, Hirano-ku, Osaka, 547-0003, Japan S-13815IZ-C1 2002 Icom Inc. INTRODUCTION DANGER This service manual describes the latest service information for the IC-V8000 VHF FM TRANSCEIVER at the time of pub- lication. ORDERING PARTS Be sure to include the

2、 following four points when ordering replacement parts: 1. 10-digit order numbers 2. Component part number and name 3. Equipment model name and unit name 4. Quantity required 1110003200 S.ICTA31136FNIC-V8000 MAIN UNIT5 pieces 8810006050 Screw Icom screw E7 IC-V8000 Chassis10 pieces Addresses are pro

3、vided on the inside back cover for your convenience. NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 16 V. This will ruin the transceiver. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities of the power supply when conn

4、ecting the transceiver. DO NOT apply an RF signal of more than 20 dBm (100mW) to the antenna connector. This could damage the trans- ceivers front end. REPAIR NOTES 1. Make sure a problem is internal before disassembling the transceiver. 2. DO NOT open the transceiver until the transceiver is dis- c

5、onnected from its power source. 3. DO NOT force any of the variable components. Turn them slowly and smoothly. 4. DO NOT short any circuits or electronic parts. An insulat- ed turning tool MUST be used for all adjustments. 5. DO NOT keep power ON for a long time when the trans- ceiver is defective.

6、6. DO NOT transmit power into a signal generator or a sweep generator. 7. ALWAYS connect a 50 dB to 60 dB attenuator between the transceiver and a deviation meter or spectrum ana- lyzer when using such test equipment. 8. READ the instructions of test equipment thoroughly before connecting equipment

7、to the transceiver. To upgrade quality, any electrical or mechanical parts and internal circuits are subject to change without notice or obligation. VERSION Asia C.S.America U.S.A. SYMBOL SEA CSA CSA-1 USA-2 USA-3 SUPPLIED MICROPHONE HM-118N HM-118TN HM-133V HM-118TAN SECTION1SPECIFICATIONS SECTION2

8、INSIDE VIEWS SECTION3DISASSEMBLY AND OPTION INSTRUCTIONS SECTION4CIRCUIT DESCRIPTION 4-1RECEIVER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1 4-2TRANSMITTER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9、 . . . . . . . . . . . . . . . . . . .4-2 4-3PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3 4-4POWER SUPPLY CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

10、-3 4-5PORT ALLOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4 SECTION5PARTS LIST SECTION6MECHANICAL PARTS AND DISASSEMBLY 6-1IC-V8000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11、. . . . . . . . . . . . . . .6-1 6-2HM-133V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3 SECTION7SEMI-CONDUCTOR INFORMATION SECTION8BOARD LAYOUTS 8-1HM-133V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1 8-2LOGIC BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2 8-3MAIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13、 . . . . . . . . . . . . . . . . . . . . .8-4 SECTION9BLOCK DIAGRAM SECTION10VOLTAGE DIAGRAM 10-1MAIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1 10-2LOGIC BOARD . . . . . . . . . . . . . . . . . . . . . . . . .

14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-2 10-3HM-133V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-3 TABLE OF CONTENTS 1 - 1 GENERAL Frequency coverage: *Specifications Guaranteed: 14414

15、8 MHz only Type of emission: FM (F2D / F3E) Frequency stability: 10 ppm (10C to +60C; +14F to +140F) Tuning steps: 5, 10, 12.5, 15, 20, 25, 30 or 50 kHz Antnna connector: SO-239 (50 ) Power supply requirement: 13.8 V DC (Operable voltage range: 11.7 to 15.9 V) (negative ground) Number of memory chan

16、nel: 207 channels (including 6 scan edges and 1 call channel) Call channel: 1 channel Scanning mode: Full, Program, Priority, Memory, Channel, Skip, Tone, DTCS, Bank and WX Current drain (approx.): Usable temperature range: 10C to +60C; +14F to +140F Dimensions (projections not included): 150(W) 50(

17、H) 150(D) mm; 5 2932(W) 1 3132(H) 5 2932(D) in. Weight: 1.09 kg; 12.3 oz.; 38.4 oz TRANSMITTER RF output power (at 13.8 V DC): 75 W / 25 W / 10 W / 5 W (High / Middle High / Middle Low / Low) Modulation system: Variable reactance frequency modulation Maximum frequency deviation: Narrow: 2.5 kHz*; Wi

18、de: 5.0 kHz Spurious emissions: Less than 60 dB Microphone connector: 8-pins modular (600 ) RECEIVER Receive system: Double conversion superheterodyne system Intermediate frequencies: 1st21.7 MHz 2nd450 kHz Sensitivity: 0.15 V at 12 dB SINAD (typical) Squelch sensitivity: 0.08 V at threshold (typica

19、l) Selectivity: Narrow; More than 3.0 kHz at 6 dB, Less than 9.0 kHz at 55 dB* Wide; More than 6.0 kHz at 6 dB, Less than 14.0 kHz at 60 dB Spurious and image rejection: 60 dB (typical) Audio output power (at 7.2 V DC): More than 2.0 W at 10% distortion with an 8 load Ext. speaker connector: 3-condu

20、ctor 3.5(d) mm (18”)/8 *USA version only All stated specifications are subject to change without notice or obligation. Transmit Receiving SECTION 1SPECIFICATIONS Version USA SEA CSA Receive 136.000174.000 MHz* Transmit 144.000148.000 MHz 140.000150.000 MHz* 136.000174.000 MHz* 15 A 9.0 A 6.0 A 5.0 A

21、 1.0 A 0.8 A High (75 W) Middle High (25 W) Middle Low (10 W) Low (5 W) Max. audio Stand-by SECTION 2INSIDE VIEWS 2 - 1 MAIN UNIT LOGIC BOARD Reference oscillator (X1: CR-659) VCO circuit Antenna switching circuit (D12, D27: XB15A407, D19: XB15A308, D16: HVU131TRF) AF power amplifier (Q23: RD70HVF1)

22、 1st IF filter (FI3, FI4: FL-310) 2nd IF filter (FI1: CFWS450F, FI2: CFWS450HT) EEPROM (IC5: HN58X2432TI) CPU (IC7: HD6433876B53H) System clock (X1: CR-663) Speaker Reset IC (IC4: S-80942ANMP-DD6) LOGIC board SECTION 3DISASSEMBLY AND OPTION INSTRUCTIONS 3 - 1 Cover MP10 Front panel Chassis MP9 MP6 M

23、P15 J5 (MF1) J6 (SP7) Chassis Main unit MP6 MP6 MP7 MP4 J1 A REMOVING THE COVER 1 Unscrew 4 screws, MP10. 2 Remove the cover in the direction of the arrow. REMOVING THE FRONT PANEL 1 Unscrew 3 screws, MP9. 2 Unplug J6 to separate front panel and chassis. 3 Remove the front panel in the direction of

24、the arrow. 4 Unplug J5 to separate fan and chassis. 5 Unscrew 2 screws, MP6, to separate MP15 and chassis. REMOVING THE MAIN UNIT 1 Unscrew 11 screws, MP6, and 2 screws, MP7, and 2 screws, MP4. 2 Unsolder 3 points, A, to remove the antenna connector. 3 Remove the Main unit in the direction of the ar

25、row. OPTIONAL UNIT INSTALLATION 1 Install the optional unit as illustrated below. Insert it tight- ly to avoid bad contact. 4 - 1 SECTION 4CIRCUIT DESCRIPTION 4-1RECEIVER CIRCUITS 4-1-1ANTENNA SWITCHING CIRCUIT (MAIN UNIT) Received signals passed through the low-pass filter (L44, L47, L48, L51, C190

26、, C197, C203, C208, C210, C217, C218). The filtered signals are applied to the 1/4 type antenna switching circuit (D16, D19). The antenna swtiching circuit functions as a low-pass filter while transmitting. However, its impedance becomes very high while D16 and D19 are turn ON. Thus transmit signals

27、 are blocked from entering the receiver circuits. The antenna switching circuit employs a 1/4 type diode swtiching sys- tem. The passed signals are then applied to the RF amplifi- er circuit. 4-1-2RF CIRCUIT (MAIN UNIT) The RF circuit amplifies signals within the range of frequen- cy coverage and fi

28、lters out-of-band signals. The signals from the antenna switching circuit are applied to the limitter (D15), and are then passed through the band- pass filter (D13, L43, C183, C182). The filtered signals are amplified at the RF amplifier (Q27), then applied to the 1st mixer circuit after out-of-band

29、 signals are suppressed at the bandpass filter (D9D11). D9D11, D13 employ varactor diodes that track the band- pass filters and are controlled by the T1T3 signals from the D/A convertor (IC5, pins 10, 11, 23). These diodes tune the center frequency of an RF passband for wide bandwidth receiving and

30、good image response rejection. 4-1-31ST MIXER AND 1ST IF CIRCUITS (MAIN UNIT) The 1st mixer circuit converts the received signal to a fixed frequency of the 1st IF signal with a PLL output frequency. By changing the PLL frequency, only the desired frequency will pass through two crystal filters at t

31、he next stage of the 1st mixer. The signals from the RF circuit are mixed at the 1st mixer (Q19) with a 1st LO signal coming from the VCO circuit to produce a 21.70 MHz 1st IF signal. The 1st IF signal is applied to two crystal filters (FI3 and FI4) to suppress out-of-band signals. The filtered 1st

32、IF signal is applied to the IF amplifier (Q16), then applied to the 2nd mixer circuit (IC4, pin 16). 4-1-42ND IF AND DEMODULATOR CIRCUITS (MAIN UNIT) The 2nd mixer circuit converts the 1st IF signal to a 2nd IF signal. A double conversion superheterodyne system (which converts receive signal twice)

33、improves the image rejection ratio and obtain stable receiver gain. The 1st IF signal from the IF amplifier is applied to the 2nd mixer section of the FM IF IC (IC4, pin 16), and is mixed with the 2nd LO signal to be converted to a 450 kHz 2nd IF sig- nal. The FM IF IC contains the 2nd mixer, limite

34、r amplifier, quad- rature detector and active filter circuits. A 21.25 MHz 2nd LO signal is produced at the PLL circuit. The 2nd IF signal from the 2nd mixer (IC4, pin 3) passes through a ceramic filter (FI1; When wide is selected, F2; When Narrow is selected. (Narrow is USA version only.) to remove

35、 unwanted heterodyned frequencies. It is then ampli- fied at the limiter amplifier (IC4, pin 5) and applied to the quadrature detector (IC4, pins 10, 11) to demodulate the 2nd IF signal into AF signals. 4-1-5AF CIRCUIT (MAIN AND LOGIC UNITS) The AF amplifier circuit amplifies the demodulated AF sig-

36、 nals to drive a speaker. AF signals from the FM IF IC (IC2, pin 9) are applied to the analog swtich (LOGIC UNIT; IC6, pin 1) via the high pass fil- ter (IC3c, pins 9, 8). The output signals from pin 11 are applied to the volume adjustment pot (LOGIC UNIT; R31). The signals are applied to the AF pow

37、er amplifier (IC9, pin 1) after passing through the AFmute swtich (Q29). Mixer 16 Limiter amp. 2nd IF filter 450 kHz PLL IC IC1 X1 21.25 MHz IC4 TA31136F 12 1st IF from the IF amplifier (Q16) SD signal to the CPU pin 97 11109 8753 AF signal DETO R5V X2 R55 C84C85 R64R59 R71 SQLIN signal from the D/A

38、 convertor (IC5, pin 214 R73 C105C101 C116 2 161 Active filter FI2 Noise detector FM detector 13 NOIS signal to the CPU pin 19 RSSI Noise comp. R63 LPF 2ND IF AND DEMODULATOR CIRCUITS 4 - 2 The AF signals are applied to the AF power amplifier circuit (IC9, pin 1) to obtain the specified audio level.

39、 The amplified AF signals, output from pin 4, are applied to the internal speaker (CHASSIS UNIT; SP1) via the speaker jack (J6) when no plug is connected to the external speaker jack (J1). 4-1-6SQUELCH CIRCUIT (MAIN AND LOGIC UNITS) A squelch circuit cuts out AF signals when no RF signals are receiv

40、ed. By detecting noise components in the AF signals, the squelch switches the analog swtich. A portion of the AF signals from the FM IF IC (IC4, pin 9) are applied to the D/A converter (IC5, pin 13) as the DETO sig- nal. The signals from the D/A converter (IC5, pin 14) are applied to the FM IF IC ac

41、tive filter section (IC4, pin 8) where noise components are amplified and detected with an inter- nal noise detector via the SQLIN line. The trigger circuit converts the detected signals to a HIGH or LOW signal and applies this (from pin 13) to the CPU (LOGIC UNIT; IC7, pin 19) as the NOIS signal.Th

42、e CPU controls the analog swtich IC (LOGIC UNIT; IC6) via the expander IC (LOGIC UNIT; IC8). When the CPU receives a HIGH level NOIS signal, the CPU controls the RMUT line to cut the AF signals at the analog swtich IC (LOGIC UNIT; IC6). At the same time, the AFON line controls the AF mute circuit (Q

43、29) to cut out the VOLOUT signal for the AF power amplifier (IC9). 4-2TRANSMITTER CIRCUITS 4-2-1MICROPHONE AMPLIFIER CIRCUIT (LOGIC AND MAIN UNITS) The microphone amplifier circuit amplifies audio signals with +6 dB/octave pre-emphasis from the microphone to a level needed for the modulation circuit

44、. The AF signals from the microphone pass through the MIC switch (IC2, D4) and high-pass filter (IC3a, pin 2), and are then applied to the microphone amplifier circuit (IC3d, pin 12) via the R39 and C47 for +6 dB/octave pre-emphasis. The amplified AF signals are applied to the analog swtich (IC6, pi

45、n 4), and are then applied to the D/Aconverter (MAIN UNIT; IC5, pin 1) via the MODIN signal. The AF signals are applied to the modulator circuit via the MOD signal. 4-2-2MODULATION CIRCUIT (MAIN UNIT) The modulation circuit modulates the VCO oscillating signal (RF signal) using the microphone audio

46、signals. The audio signals (SHIFT) change the reactance of D2 to modulate an oscillated signal at the VCO (Q6, D4). The oscillated signal is amplified at the LO (Q9) and buffer (Q11) amplifiers, then applied to the TX/RX switch circuit (D6, D7). 4-2-3DRIVE/POWER AMPLIFIER CIRCUITS (MAIN UNIT) The si

47、gnal from the VCO circuit passes through the TX/RX swtiching circuit (D6) and is amplified at the pre-drive (Q17), drive (Q18, Q20) and power (Q23) amplifiers to obtain 75 W of RF power (at 13.8 V DC/typical). The amplified signal passes through the low-pass filter (L37, L39, C151, C156, C159, C167,

48、 C176, C227C229), and then applied to the antenna swtiching circuit (D12). The signal is applied to the antenna connector (CHASSIS UNIT; J1) after being passed through the low-pass filter (L44, L47, L48, L51, C190, C197, C203, C208, C210, C217, C218). The bias current of the drive (Q18, Q20) and pow

49、er (Q23) amplifiers is controlled by the APC circuit to stabilize the out- put power. 4-2-4APC CIRCUIT (MAIN UNIT) The APC (Automatic Power Control) circuit (IC6a, Q26) pro- tects drive and power amplifiers from excessive currents and selects HIGH or LOW output power. The output voltage from the power detector circuit (D14, D17) is applied to the differential amplifier (IC6a, pin 2), and the “T3” signal from the D/A converter (IC5, pin 23) is applied to the other input for reference. When the driving current increases, the input voltag