VERTEX YAESU FT-8800 Service Repair Manual

Dual Band FM Transceiver FT-8800R Technical Supplement Introduction This manual provides technical information necessary for servicing the FT-8800R Transceiver. Servicing this equipment requires expertise in handling surface-mount chip components. Attempts by non-qualified persons to service this equipment may result in permanent damage not covered by the warranty, and may be illegal in some countries. Two PCB layout diagrams are provided for each double-sided circuit board in the transceiver. Each side of thr board is referred to by the type of the majority of components installed on that side (“leaded” or “chip-only”). In most cases one side has only chip components, and the other has either a mixture of both chip and leaded components (trimmers, coils, electrolytic capacitors, ICs, etc.), or leaded components only. While we believe the technical information in this manual to be correct, Vertex Standard assumes no liability for damage that may occur as a result of typographical or other errors that may be present. Your cooperation in pointing out any inconsistencies in the technical information would be appreciated. Specifications ..................................................... 2 Exploded View & Miscellaneous Parts ......... 3 Block Diagram .................................................... 5 Circuit Description ............................................ 7 Alignment ......................................................... 11 Contents Board Unit (Schematics, Layouts & Parts) Main Unit ...................................................................... 17 Panel Unit ..................................................................... 45 Panel-Sub Unit ............................................................. 51 VR-L Unit ...................................................................... 53 VR-R Unit ...................................................................... 54 © 2003 VERTEX STANDARD CO., LTD. (EH018M90A) VERTEX STANDARD CO., LTD. 4-8-8 Nakameguro, Meguro-Ku, Tokyo 153-8644, Japan VERTEX STANDARD US Headquarters 10900 Walker Street, Cypress, CA 90630, U.S.A. International Division 8350 N.W. 52nd Terrace, Suite 201, Miami, FL 33166, U.S.A. YAESU EUROPE B.V. P.O. Box 75525, 1118 ZN Schiphol, The Netherlands YAESU UK LTD. Unit 12, Sun Valley Business Park, Winnall Close Winchester, Hampshire, SO23 0LB, U.K. VERTEX STANDARD HK LTD. Unit 5, 20/F., Seaview Centre, 139-141 Hoi Bun Road, Kwun Tong, Kowloon, Hong Kong 1 4 6 5 2 3 LOW SQL SQL VOL VOL LOW V/M HM SCN V/M HM SCN KEY2 PWR

2 Specifications GENERAL Frequency Range: RX: 108.000 - 520.000 MHz, 700.000 - 999.995 MHz (Cellular Blocked) TX: 144.000 - 146.000 MHz (or 144.000 - 148.000 MHz), 430.000 - 440.000 MHz (or 430.00 - 450.000 MHz) Channel Steps: 5/10/12.5/15/20/25/50 kHz Modes of Emission: F3, F2 Antenna Impedance: 50-Ohms, unbalanced (Antenna Duplexer built-in) Frequency Stability: ±5 ppm @ 14° F ~ +140° F (–10 °C ~ +60 °C) Operating Temperature Range: –4° F ~ +140° F (–20 °C ~ +60 °C) Supply Voltage: 13.8 VDC (±15%), negative ground Current Consumption (Approx.): RX: 0.5 A (Squelched) TX: 8.5 A (144 MHz), 8.0 A (430 MHz) Case Size (W x H x D): 5.5” x 1.6” x 6.6” (140 x 41.5 x 168 mm) (w/o knobs & connectors) Weight (Approx.): 2.2 lb (1 kg) TRANSMITTER Output Power: 50/20/10/5 W (144 MHz), 35/20/10/5 W (430 MHz) Modulation Type: Variable Reactance Maximum Deviation: ±5 kHz Spurious Radiation: Better than –60 dB Microphone Impedance: 2 kΩ DATA Jack Impedance: 10 kΩ RECEIVER Circuit Type: Double-conversion superheterodyne Intermediate Frequencies: 45.05 MHz/450 kHz (Main band), 47.25 MHz/450 kHz (Sub band) Sensitivity (for 12dB SINAD): Better than 0.2 µV Squelch Sensitivity: Better than 0.16 µV Selectivity (–6dB/–60dB): 8 kHz/30 kHz Maximum AF Output: 2 W @ 8 Ω for 5% THD AF Output Impedance: 4-16 Ω Specifications are subject to change without notice, and are guaranteed within the 144 and 430 MHz amateur bands only. Frequen- cy ranges will vary according to transceiver version; check with your dealer.

3 Exploded View & Miscellaneous Parts RA0396700 LIGHT GUIDE RA0396800 LCD HOLDER RA0396900 (x2 pcs) INTER CONNECTOR RA0397100 REFLECTOR SHEET RA0397000 DIFFUSER SHEET M2090034A FAN M4090149 SPEAKER RA0404400 (x2 pcs) KNOB RA0404300 (x2 pcs) KNOB RA0404200 (x2 pcs) ENCODER KNOB R6054387B (x2 pcs) SPECIAL NUT RA0507300 FRONT PANEL ASSY RA0407200 SPACER T9207010A WIRE ASSY RA040710A LIGHT SHEET T9206438A WIRE ASSY R0150630 HOLDER RA02132A0 HIMERON TAPE CS1770001 CASE (W/O NYLON NET) T9206228 WIRE ASSY RA040480A SUB PANEL ASSY (W/ COIL SPRING, RELEASE KNOB) T9101509 CT CABLE S5000206 FAN GUARD P1090984 CONNECTOR RA0446200 LEAF SPRING RA0396100 REAR PANEL RA02668AA CHASSIS RA0441300 PAD RA0438700 RUBBER G6090147A LCD VR-L Unit VR-R UNIT PANEL Unit PANEL-SUB UNIT MAIN UNIT RA0415200 (x2 pcs) GROUND PLATE R0137550 COIL SPRING RA026900A RELEASE KNOB                                            No. VXSTD P/N DESCRIPTION QTY.  U23116007 TAPTITE SCREW M2X16B 4  U31206007 OVAL HEAD SCREW M2.6X6B 14  U44308002 TAPTITE SCREW M3X8NI 17  U03310002 SEMS SCREW ASM3X10NI 4  U20308002 BINDING HEAD SCREW M3X8NI 2  U20318007 BINDING HEAD SCREW M3X18B 4 Non-designated parts are available only as part of a designated assembly.  SUPPLIED ACCESSORIES VXSTD P/N DESCRIPTION QTY. AAA43X001 MH-48 A6J 1 A07530005 MH-42 B6JS (depending on transceiver version) T9021715 DC POWER CORD W/FUSE 1 Q0000081 SPARE FUSE 15 A 2

4 Exploded View & Miscellaneous Parts Note:

Block Diagram 5

Block Diagram 6 Note:

7 Circuit Description Receiver Signal Path “Main” Band 430 MHz Signal The 430 MHz signal is passed through a high-pass filter network and a low-pass filter network to the antenna switch diodes D1029, D1030 (both RSL135) and D1001 (HSC277TRF), then passed through another low-pass filter network to the “Main” band RF amplifier Q1001 (3SK296ZQ). The amplified 430 MHz signal is passed through the band switch D1002 (HSC277) to the varactor-tuned band-pass filter network consisting of D1004, D1005, and D1006 (all HVC350B) and associated circuitry, then applied to the first mixer Q1003 (3SK296ZQ). Meanwhile, the UHF local signal from the UHF-VCO/B Q1116 (2SC5006) is delivered to first mixer Q1003, yielding the 45.05 MHz “Main” band first IF. “Main” Band 144 MHz Signal The 144 MHz signal is passed through a low-pass filter network and a high-pass filter network to the antenna switch diodes D1113, D1114 (both UM9957F), D1115, D1116 (both RLS135) and D1117 (both RLS135) then passed through another low-pass filter network to the “Main” band RF amplifier Q1014 (3SK296ZQ). The amplified 144 MHz signal is passed through a varactor-tuned band-pass filter network consisting of D1017, D1018, D1019 (all HVC365) and associated circuitry to the first mixer Q1016 (3SK296ZQ). Meanwhile, the VHF local signal from the VHF-VCO/B Q1120 (2SC5374) is delivered to first mixer Q1016, yielding the 45.05 MHz “Main” band first IF. “Main” Band IF and AF Signals The 45.05 MHz “Main” band first local signal is delivered to the monolithic crystal filter XF1001 which strips away unwanted mixer products, then is passed through IF amplifier Q1027 (2SC4400) to the IF IC Q1044 (TA31136FN). Meanwhile, a portion of the output of 11.15 MHz crystal X1002 is multiplied fourfold by Q1042 (2SC4400) to pro- vide the 44.6 MHz second local signal, then delivered to the IF IC Q1044. Within the IF IC Q1044, the 44.6 MHz second local signal is mixed with the 45.05 MHz “Main” band first local signal to produce the 450 kHz “Main” band second IF. The 450 kHz “Main” band second IF is passed through the filter switch D1039/D1041 (both HSC277) to the ceramic filter CF1001 (CFWM450E) which strips away all but the desired signal, then it passes through the IF amplifier within Q1044 to the ceramic discriminator CD1001 (CDBM450C24), which removes any amplitude variations in the 450 kHz IF signal before detection of speech. The demodulated “Main” band audio is passed through the de-emphasis network, audio switch D1047 (DAN222), low-pass filter network (consisting of Q1052 (NJM2902V) and associated circuitry), and a high-pass filter network (consisting of Q1054 (NJM2904V) and associated circuitry). The filtered audio signal is passed through the audio volume control IC Q1063 (M51132FP), which adjusts the audio sensitivity to compensate for audio level variations, then is delivered to the audio switch Q1066 and Q1067 (both TC4W66FU). When the internal speaker is selected, the audio signal is amplified by Q1069 (TDA7233D) then applied to the internal loudspeaker. When the external speaker is selected, the audio signal is amplified by Q1068 (LA4425A), then it passes through the EXT SP jack to the external loudspeaker. “Sub” Band 430 MHz Signal The 430 MHz signal is passed through a high-pass filter network and a low-pass filter network to the antenna switch diodes D1029, D1030 (both RSL135) and D1001 (HSC277TRF), then passed through another low-pass filter network to the “Sub” band RF amplifier Q1002 (3SK296ZQ). The amplified 430 MHz signal is delivered through the band switch D1009 (HSC277) to the varactor-tuned band- pass filter network consisting of D1011, D1012, D1013 (all HVC350B) and associated circuitry, then applied to the first mixer Q1005 (3SK296ZQ). Meanwhile, the UHF local signal from the UHF-VCO/A Q1123 (2SC5006) is delivered to first mixer Q1005, yielding the 47.25 MHz “Sub” band first IF. “Sub” Band 144 MHz Signal The 144 MHz signal is passed through a low-pass filter network and a high-pass filter network to the antenna switc diodes D1113, D1114 (both UM9957F), D1115, D1116 (both RLS135) and D1117 (both RLS135), then passed through another low-pass filter network to the “Sub” band RF amplifier Q1015 (3SK296ZQ). The amplified 144 MHz signal is passed through the varactor-tuned band-pass filter network consisting of D1020, D1021, D1022 (all HVC365) and associated circuitry to the first mixer Q1017 (3SK296ZQ). Meanwhile, the VHF local signal from the VHF-VCO/A Q1126 (2SC5374) is delivered to first mixer Q1017, yielding the 47.25 MHz “Sub” band first IF. “Sub” Band IF and AF Signal The 47.25 MHz “Sub” band first IF is delivered to the monolithic crystal filter XF1002 which strips away unwanted mixer products, then passed through the IF amplifier Q1035 (2SC4400) to the IF IC Q1047 (TA31136FN).

8 Meanwhile, a portion of the output of 11.7 MHz crystal X1003 is multiplied fourfold by Q1043 (2SC4400) to pro- vide the 46.8 MHz second local signal, then applied to the IF IC Q1047. Within the IF IC Q1047, the 46.8 MHz second local signal is mixed with the 47.25 MHz “Sub” band first local signal to produce the 450 kHz “Sub” band second IF. The 450 kHz “Sub” band second IF is delivered to the ceramic filter CF1003 (CFWM450E) which strips away all but the desired signal, then passed through the IF amplifier within Q1047 to the ceramic discriminator CD1002 (CDBM450C24) which removes any amplitude variations in the 450 kHz IF signal before detection of speech. The demodulated “Sub” band audio is passed through the de-emphasis network, audio switch D1048 (DAN222), low-pass filter network (consisting of Q1053 (NJM2902V) and associated circuitry) and the high-pass filter network (consisting of Q1054 (NJM2904V) and associated circuitry). The filtered audio signal is passed through the audio volume control IC Q1063 (M511312FP), which adjusts the audio sensitivity to compensate for audio level variations, then is delivered to the audio switch Q1066 and Q1067 (both TC4W66FU). When the internal speaker is selected, the audio signal is amplified by Q1069 (TDA7233D) then applied to the internal loudspeaker. When the external speaker is selected, the audio signal is amplified by Q1068 (LA4425A), then it passes through the EXT SP jack to the external loudspeaker. Squelch Control “Main” Band When no carrier is being received on the “Main” band, noise at the output of the detector stage in Q1044 is amplified and band-pass filtered by the noise amp section of Q1044. The resulting DC voltage is delivered to pin 5 of main CPU Q1104 (M38268MCL), which compares the squelch threshold level to that which set by the front panel SQL knob. While no carrier is being received on the “Main” band, pin 2 of Q1105 remain “low,” to disable the audio output from the speaker. “Sub” Band When no carrier is being received on the “Sub” band, noise at the output of the detector stage in Q1047 is amplified and band-pass filtered by the noise amp section of Q1047. The resulting DC voltage is delivered to pin 2 of main CPU Q1104, which compares the squelch threshold level to that which set by the front panel SQL knob. While no carrier is being received on the “Right” band, pin 15 of Q1105 remain “low,” to disable the audio output from the speaker. Transmitter Signal Path AF Signal The speech signal from the microphone is passed through the MIC jack J3003 to the AF amplifier Q3001 (NJM2904V) on the PANEL-SUB UNT. The amplified speech signal is passed through the panel separation jacks J3001 and J1005 to the MAIN Unit. On the MAIN UNIT, the speech signal is delivered to the limiting amplifier Q1074 (NJM2902V) to prevent over-modulation, then is delivered to a low-pass filter network consisting of Q1074 and associated circuitry. 430 MHz Signal The adjusted speech signal from Q1074 is passed through transistor switch Q1114, Q1115 (both DTC144EE) to varactor diodes D1079 (HVC375B) and D1080 (HVC350B), which frequency modulate the transmitting VCO, made up of UHF-VCO/B Q1116 ( 2SC5006 ) and D1081 (HSC277). The modulated transmit signal is passed through buffer amplifiers Q1117, Q1118 and Q1119 (all 2SC5006) and diode switches D1099, D1101 (both HSC277) to the pre- drive amplifier Q1132 (2SK2596). The amplified transmit signal from Q1132 is passed through diode switch D1106 (HSC277) and the driver amplifier Q1134 (RD07MVS1) to the diode switch D1107 (HSC277), then finally amplified by power amplifier Q1135 (RD70HVF1), providing up to 35 Watts of power output. These three stages of the power amplifier’s gain are controlled by the APC circuit. The 35-Watt RF signal is passed through a high-pass filter network to the antenna switch D1118, D1119, and D1120 (all UM9957F), then passed through a low-pass filter network and another high-pass filter network to the ANT jack. 144 MHz Signal The adjusted speech signal from Q1074 is passed through the transistor switch Q1114, Q1115 (both DTC144EE) to varactor diodes D1082 and D1085 (both HVC365), which frequency modulate the transmitting VCO, made up of VHF-VCO/B Q1120 (2SC5374) and D1083 (HVC131). The modulated transmit signal is passed through buffer amplifiers Q1121 and Q1122 (both 2SC5374) and diode switches D1089 and D1102 (both HSC277) to the pre-drive amplifier Q1132 (2SK2596). The amplified transmit signal from Q1132 is passed through the diode switch D1105, D1106 (both HSC277) and the driver amplifier Q1134 (RD07MVS1) to diode switch D1108 (RLS135), then finally amplified by power amplifier Q1135 (RD70HVF1) up to 50 Watts of power output. These three stages of the power amplifier’s gain are controlled by the APC circuit. Circuit Description

9 The 50-Watt RF signal is passed through a low-pass filter network to the antenna switch D1113 and D1114 (UM9957F), then passed through a high-pass filter network and another low-pass filter network to the ANT jack. APC (Automatic Power Control) Circuit 430 MHz A portion of the power amplifier output is rectified by D1121 and D1122 (both MA2S728) then delivered to APC Q1129 (NJM2904V), as a DC voltage which is proportional to the output level of the power amplifier. At Q1129, the rectified DC voltage from the power amplifier is compared to the reference voltage from the main CPU Q1104 to produce a control voltage, which regulates the supply voltage to the pre-drive amplifier Q1132 (2SK2596), driver amplifier Q1134 (RD07MVS1), and power amplifier Q1135 (RD70HVF1), so as to maintain stable output power under varying antenna loading con- ditions. 144 MHz A portion of the power amplifier output is rectified by D1109 and D1110 (both MA2S728) then delivered to APC Q1129 (NJM2904V), as a DC voltage which is proportional to the output level of the power amplifier. At Q1129, the rectified DC voltage from the power amplifier is compared to the reference voltage from the main CPU Q1104 to produce a control voltage, which regulates the supply voltage to the pre-drive amplifier Q1132 (2SK2596), driver amplifier Q1134 (RD07MVS1), and power amplifier Q1135 (RD70HVF1), so as to maintain stable output power under varying antenna loading con- ditions. PTT (Push to Talk) Circuit 430 MHz When the PTT switch is pressed, pin 8 of sub CPU Q2001 (M38223M4M) goes “high,” which sends the “PTT” command to main CPU Q1104. When the “PTT” command is received, the main CPU controls the I/O IC Q1095 (BU2090FS), causing pin 8 of Q1095 to go “low” which activates the UHF TX switch section of Q1096 (IMT17). When the UHF TX switch section of Q1096 is activated, it controls the antenna switch diodes D1118, D1119, and D1120 (all UM9957F), modulator switching diode D1088 (DAN222), modulator switching transistor Q1114 and Q1115 (both DTC144EE), diode switches D1099, D1101, D1106 and D1107 (all HSC277), and APC switches Q1130 (DTA144EE) and Q1131 (DTC144EE), which activate the 430 MHz transmitter circuit. 144 MHz When the PTT switch is pressed, pin 8 of sub CPU Q2001 (M38223M4M) goes “high,” which sends the “PTT” command to main CPU Q1104. When the “PTT” command is received, the main CPU controls the I/O IC Q1095 (BU2090FS), causing pin 9 of Q1095 to go “low” which activates the VHF TX switch section of Q1096 (IMT17). When the VHF TX switch section of Q1096 is activated, it controls the antenna switch diodes D1113 and D1114 (both UM9957F), D1117 (HSC277) and D1115, D1116 (RLS135), modulator switching transistor Q1114 and Q1115 (both DTC144EE), diode switches D1089, D1102, D1105, D1106 (all HSC277) and D1108 (RLS135), and APC switches Q1130 (DTA144EE) and Q1131 (DTC144EE), which activate the 144 MHz transmitter circuit. PLL Circuit “Main” band A portion of the output from UHF-VCO/B Q1116 (2SC5006) is passed through buffer amplifier Q1117 (2SC5006) and diode switch D1086 (HSC277) to the pro- grammable divider section of the PLL IC Q1109 (MB15A02PFV1), where it is divided according to the frequency dividing data associated with the operating frequency input from the main CPU Q1104. It is then sent to the phase comparator. A portion of the output from the VHF-VCO/B Q1120 (2SC5374) is passed through buffer amplifier Q1121 (2SC5374) and diode switch D1087 (HSC277) to the pro- grammable divider section of the PLL IC Q1109, where it is divided according to the frequency dividing data associated with the operating frequency input from the main CPU Q1104. It is then sent to the phase comparator. The 11.15 MHz reference oscillator X1002 frequency is divided by the reference frequency divider section of Q1109 into 2230 or 1784 parts, to become 5 kHz or 6.25 kHz comparative reference frequencies, which are utilized by the phase comparator. The phase comparator section of Q1109 compares the phase between the frequency-divided oscillation frequency of the VCO circuit and the comparative frequency, and its output is a pulse corresponding to the phase differ- ence. This pulse is integrated by the loop filter into a control voltage (VCV) to control the oscillation frequency of the VCOs. Circuit Description

10 “Sub” band A portion of the output from the UHF-VCO/A Q1123 (2SC5006) is passed through buffer amplifier Q1124 (2SC5006) and diode switch D1093 (HVC131) to the pro- grammable divider section of the PLL IC Q1122 (MB15A02PFV1), where it is divided according to the frequency dividing data associated with the operating frequency input from the main CPU Q1104. It is then sent to the phase comparator. A portion of the output from the VHF-VCO/A Q1126 (2SC5374) is passed through buffer amplifier Q1127 (2SC5374) and diode switch D1097 (HVC131) to the pro- grammable divider section of the PLL IC Q1122, where it is divided according to the frequency dividing data associated with the operating frequency input from the main CPU Q1104. It is then sent to the phase comparator. The 11.7 MHz reference oscillator X1003 frequency is divided by the reference frequency divider section of Q1122 into 2340 or 1872 parts to become 5 kHz or 6.25 kHz comparative reference frequencies, which are utilized by the phase comparator. The phase comparator section of Q1122 compares the phase between the frequency-divided oscillation frequency of the VCO circuit and the comparative frequency, and its output is a pulse corresponding to the phase differ- ence. This pulse is integrated by the loop filter into a control voltage (VCV) to control the oscillation frequency of the VCOs. Circuit Description Power Supply Line When the user presses and holds in the “Right” VOL knob for 2 seconds, pin 23 of the main CPU Q1104 goes “low” and pin 40 of main CPU Q1104 goes “high,” which activates the power switch Q1078 (2SB1301) and Q1082 (2SC4617), to supply 13.8 VDC to each circuit in the transceiver.

VERTEX YAESU FT-8800 Service Repair Manual

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