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FT-7900R/E Technical Supplement

Dual Band FM Transceiver

FT-7900R/E

Technical Supplement

Introduction

This manual provides technical information necessary for servicing the FT-7900R/E 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 dam-
age 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 ................................................ A-1

Exploded View & Miscellaneous Parts ..... B-1

Block Diagram ................................................ C-1

Circuit Description ....................................... D-1

Alignment ....................................................... E-1

Contents

Board Unit (Schematics, Layouts & Parts)

MAIN Unit................................................. F-1

PANEL Unit ............................................. G-1
CH Unit ..................................................... H-1

©

2011 VERTEX STANDARD CO., LTD.          EH016M93B

Important Note

The transceiver was assembled using Pb (lead) free solder, based on the RoHS specification.
Only lead-free solder (Alloy Composition: Sn-3.0Ag-0.5Cu) should be used for repairs performed on this appara-
tus. The solder stated above utilizes the alloy composition required for compliance with the lead-free specifica-
tion, and any solder with the above alloy composition may be used.

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.

YAESU UK LTD.

Unit 12, Sun Valley Business Park, Winnall Close
Winchester, Hampshire, SO23 0LB, U.K.

VERTEX STANDARD HK LTD.

Unit 1306-1308, 13F., Millennium City 2,  378 Kwun Tong Road,
Kwun Tong, Kowloon, Hong Kong

VERTEX STANDARD 

(

AUSTRALIA

)

 PTY., LTD.

Tally Ho Business Park, 10 Wesley Court, East Burwood, VIC, 3151

Summary of Contents for FT-7900E

Page 1: ...l or other errors that may be present Your cooperation in pointing out any inconsistencies in the technical information would be appreciated Specifications A 1 Exploded View Miscellaneous Parts B 1 Bl...

Page 2: ...tance Maximum Deviation 5 kHz 2 5 kHz Spurious Radiation At least 60 dB below Microphone Impedance 2 k DATA Jack Impedance 10 k Receiver Circuit Type Double conversion superheterodyne Intermediate Fre...

Page 3: ...COIL SPRING T9101536 CT CABLE RA053980A SUB PANEL CS1804001 CASE W NYLON NET RA0322600 RUBBER SHEET T9207482 USA EXP AUS T9207483 CE WIRE ASSY RA0415200 x2 pcs GROUND PLATE P1090547 CONNECTOR CE EXP A...

Page 4: ...B 2 FT 7900R E Technical Supplement Note Exploded View Miscellaneous Parts...

Page 5: ...C 1 FT 7900R E Technical Supplement Block Diagram...

Page 6: ...C 2 FT 7900R E Technical Supplement Note Block Diagram...

Page 7: ...l is applied to the ceramic filter CF1001 which strips away all but the desired shig nal and then passes through the limiter amplifier within Q1023 TA31136FN to the ceramic discriminator CD1001 which...

Page 8: ...Drive amplifier Q1086 RD07MVS1 and Power amplifier Q1087 RD70HVF1 so as to main tain stable output power under varying antenna loading conditions Circuit Description PTT Circuit When the PTT switch i...

Page 9: ...ange circuits and alignment procedures in the interest of improved performance with out notifying owners Under no circumstances should any alignment be attempt ed unless the normal function and operat...

Page 10: ...turning the radio on The display will be show in the illus tration at the right 6 Press and hold in the PWR switch for 1 2 sec ond to turn the radio off 7 Press and hold in the MHz PRI key and the Hyp...

Page 11: ...the L key as needed so that the wattmeter reading is 5 Watts 0 5 Watt 12 Press the LOW ACC key to increase the Transmit Power Level to MID2 13 Press the PTT switch to activate the transmitter and adj...

Page 12: ...ing in the L key if needed so that the deviation meter reading is between 0 50 kHz and 0 60 kHz CTCSS TX Deviation 1 Press the BAND SET key then rotate the DIAL knob to set the display to B5006 Set th...

Page 13: ...Press the V M MW key while pressing and holding in the L key 7 Press the BAND SET key then rotate the DIAL knob to set the display to B0206 8 Inject a 146 050 MHz signal at a level of 5 dB with 1 kHz...

Page 14: ...FT 7900R E Technical Supplement Alignment E 6 Note...

Page 15: ...45 05 MHz 21 6 dB 21 0 dB 45 05 MHz 12 3 dB 11 6 dB 0 83 V 0 13 V 4 94 V 2 22 V 0 82 V 0 71 V 0 11 V 0 23 V 12 73 V 12 76 V 2 09 V 0 68 V 1 23 V 4 72 V 0 69 V 45 05 MHz 23 4 dB 22 6 dB Q1023 Pin 1 4...

Page 16: ...F 2 FT 7900R E Technical Supplement Note MAIN Unit Lot 1 115...

Page 17: ...071 2SC5006 24 Q1003 1013 1014 1074 1075 2SC5277 D2 Q1012 2SC5374 NA Q1078 RQA0004PXDQS PX Q1084 BU2090FS Q1059 M51132FP Q1034 MB15A022PFV1 Q1070 TA31136FN Q1023 BU4066BCFV Q1039 NJM2902V Q1040 DTA144...

Page 18: ...2SC5374 NA Q1011 1076 1077 NJM2902V Q1028 1031 DTA144EE 16 Q1082 1088 DTC144EE 26 Q1032 1033 1036 1042 1066 1067 1079 1080 1083 NJM78L05 8C Q1049 2SB1201S Q1044 2SD1664 DA Q1085 AT24C256 Q1053 NJM2904...

Page 19: ...45 05 MHz 21 6 dB 21 0 dB 45 05 MHz 12 3 dB 11 6 dB 0 83 V 0 13 V 4 94 V 2 22 V 0 82 V 0 71 V 0 11 V 0 23 V 12 73 V 12 76 V 2 09 V 0 68 V 1 23 V 4 72 V 0 69 V 45 05 MHz 23 4 dB 22 6 dB Q1023 Pin 1 4 7...

Page 20: ...F 6 FT 7900R E Technical Supplement Note MAIN Unit Lot 116...

Page 21: ...71 2SC5006 24 Q1003 1013 1014 1074 1075 2SC5277 D2 Q1012 2SC5374 NA Q1078 RQA0004PXDQS PX Q1084 BU2090FS Q1059 M51132FP Q1034 MB15A022PFV1 Q1070 TA31136FN Q1023 BU4066BCFV Q1039 NJM2902V Q1040 DTA144E...

Page 22: ...SC5374 NA Q1011 1076 1077 NJM2902V Q1028 1031 DTA144EE 16 Q1082 1088 DTC144EE 26 Q1032 1033 1036 1042 1066 1067 1079 1080 1083 NJM78L05 8C Q1049 2SB1201S Q1044 2SD1664 DA Q1085 AT24C256 Q1053 NJM2904V...

Page 23: ...1026 CHIP CAP 1 5pF 50V CK GRM1554C1H1R5BZ01D K22178288 1 A F5 C 1027 CHIP CAP 6pF 50V CH GRM1552C1H6R0BZ01D K22178293 1 A F5 C 1028 CHIP CAP 22pF 50V CH GRM1552C1H220JZ01D K22178220 1 A E5 C 1029 CH...

Page 24: ...0V CH GRM1552C1H6R0BZ01D K22178293 1 A E5 C 1097 CHIP CAP 2pF 50V CK GRM1554C1H2R0BZ01D K22178289 1 B a3 C 1098 CHIP CAP 47pF 50V CH GRM1552C1H470JZ01D K22178228 1 B a4 C 1099 CHIP CAP 1pF 50V CK GRM1...

Page 25: ...178838 1 B h5 C 1173 CHIP CAP 0 0047uF 50V B GRM155B11H472KA01D K22178838 1 B h5 C 1174 CHIP CAP 0 0047uF 50V B GRM155B11H472KA01D K22178838 1 B h5 C 1175 CHIP CAP 1uF 10V F GRM188F11A105ZA01D K221050...

Page 26: ...B11H102KA01D K22178809 1 A B3 C 1245 CHIP CAP 0 022uF 50V B GRM188B11H223KA01D K22174839 1 A B2 C 1246 AL ELECTRO CAP 2200uF 16V RE3 16V222MI5 K40129064 1 B h2 C 1246 AL ELECTRO CAP 2200uF 16V RJ5 16V...

Page 27: ...5B11H102KA01D K22178809 1 B e6 C 1314 CHIP CAP 0 1uF 10V B GRM155B11A104KA01D K22108802 1 A D6 C 1315 CHIP TA CAP 10uF 10V TEESVA1A106M8R K78100028 1 A D6 C 1316 CHIP CAP 0 1uF 10V B GRM155B11A104KA01...

Page 28: ...50V B GRM188B11H223KA01D K22174839 1 A C4 C 1388 CHIP CAP 0 001uF 50V B GRM188B11H102KA01D K22174821 1 A C4 C 1389 CHIP CAP 1uF 25V B GRM21BB31E105KA98L K22140826 1 A C4 C 1390 CHIP CAP 10pF 50V CH G...

Page 29: ...RM2192C2D150JV01D K22230218 1 B a3 C 1449 CHIP CAP 15pF 200V CH GRM2192C2D150JV01D K22230218 1 B a3 C 1450 CHIP CAP 22pF 50V CH GRM1552C1H220JZ01D K22178220 1 B b2 C 1452 CHIP CAP 0 001uF 50V B GRM155...

Page 30: ...L G2070174 1 A E7 D 1023 DIODE MA2S72800L G2070858 1 B f7 D 1028 DIODE DAN222 TL G2070174 1 B g5 D 1030 DIODE DA221 TL G2070178 1 B h6 D 1031 DIODE HZM27WA TR E G2070530 1 B g7 D 1032 DIODE HZM27WA TR...

Page 31: ...5uH TFL0816 15 L1690493 1 B d5 L 1011 M RFC 0 082uH 2 C1608CB 82NG RF L1691044 1 B b3 L 1012 M RFC 0 056uH 2 C1608CB 56NG RF L1691041 1 B b3 L 1013 M RFC 0 047uH 2 C1608CB 47NG RF L1691040 1 B b3 L 10...

Page 32: ...46 1 A G2 L 1078 COIL 0 038uH AS050630 38N L0022818 1 A H2 L 1079 COIL A1 3 5T3 5D1 0UEW R L0022805 1 A H2 L 1080 COIL A1 3 5T3 5D1 0UEW R L0022805 1 A H3 L 1081 M RFC 0 039uH 2 C1608CB 39NG RF L16910...

Page 33: ...075 1 B g6 Q 1068 TRANSISTOR DTC144EE TL G3070075 1 A E5 Q 1069 TRANSISTOR 2SA1774 TL R G3117748R 1 A C6 Q 1070 IC MB15A02PFV1 G BND EFE1 G1092541 1 A D6 Q 1071 TRANSISTOR 2SC4617 TL R G3346178R 1 A D...

Page 34: ...16W 0 5 RR0510P 103 D J24189143 1 A G4 R 1056 CHIP RES 10k 1 16W 5 RMC1 16S 103JTH J24189037 1 B b4 R 1057 CHIP RES 47 1 16W 5 RMC1 16S 470JTH J24189009 1 B b4 R 1058 CHIP RES 47 1 16W 5 RMC1 16S 470...

Page 35: ...16W 5 RMC1 16S 221JTH J24189017 1 A E7 R 1128 CHIP RES 47 1 16W 5 RMC1 16S 470JTH J24189009 1 A D7 R 1129 CHIP RES 1k 1 16W 5 RMC1 16S 102JTH J24189025 1 B d6 R 1130 CHIP RES 4 7k 1 16W 5 RMC1 16S 47...

Page 36: ...RES 22k 1 16W 5 RMC1 16S 223JTH J24189041 1 A B1 R 1207 CHIP RES 47 1 16W 5 RMC1 16S 470JTH J24189009 1 B h5 R 1208 CHIP RES 220k 1 16W 5 RMC1 16S 224JTH J24189053 1 A B5 R 1209 CHIP RES 100k 1 16W 5...

Page 37: ...P RES 100k 1 16W 0 5 RR0510R 104 D J24189167 1 B h7 R 1280 CHIP RES 100k 1 16W 0 5 RR0510R 104 D J24189167 1 B h7 R 1281 CHIP RES 100k 1 16W 0 5 RR0510R 104 D J24189167 1 B h7 R 1282 CHIP RES 100k 1 1...

Page 38: ...RMC1 16S 222JTH J24189029 1 A D5 R 1354 CHIP RES 330 1 16W 5 RMC1 16S 331JTH J24189019 1 A D5 R 1355 CHIP RES 150 1 16W 5 RMC1 16S 151JTH J24189015 1 A D5 R 1356 CHIP RES 680 1 16W 5 RMC1 16S 681JTH...

Page 39: ...RES 330k 1 16W 5 RMC1 16S 334JTH J24189055 1 B g3 R 1422 CHIP RES 100 1 16W 5 RMC1 16S 101JTH J24189013 1 B g3 R 1423 CHIP RES 100 1 16W 5 RMC1 16S 101JTH J24189013 1 B g4 R 1424 CHIP RES 3 3k 1 16W...

Page 40: ...18 1W 5 RMC1 180JTE J24305180 1 A F3 R 1486 CHIP RES 18 1W 5 RMC1 180JTE J24305180 1 A F3 R 1487 CHIP RES 10k 1 16W 5 RMC1 16S 103JTH J24189037 1 B c3 R 1488 CHIP RES 10k 1 16W 5 RMC1 16S 103JTH J2418...

Page 41: ...G 1 FT 7900R E Technical Supplement PANEL Unit Circuit Diagram 1 58 V 5 00 V DIM 1 7 26 V DIM OFF 8 45 V DIM 1 4 36 V DIM OFF 0 V 5 00 V 3 15 V 8 68 V 3 57 V 8 90 V...

Page 42: ...HZM27WA 27A D2011 2014 M38223M4M Q2001 LC75821E Q2002 NJM2904V Q2011 NJM78L05 8C Q2003 DTA144EE 16 Q2012 DTC144EE 26 Q2005 2SA1774 FR Q2004 2SB1132 BA Q2006 Parts Layout Side B a b c d e f g h i 1 2...

Page 43: ...2C1H101JD01D K22178236 1 B d2 C 2030 CHIP CAP 100pF 50V CH GRM1552C1H101JD01D K22178236 1 B d2 C 2031 CHIP CAP 0 01uF 25V B GRM155B11E103KA01D K22148834 1 B e2 C 2032 CHIP CAP 0 001uF 50V B GRM155B11H...

Page 44: ...R 2023 CHIP RES 1k 1 16W 5 RMC1 16S 102JTH J24189025 1 B e2 R 2025 CHIP RES 1k 1 16W 5 RMC1 16S 102JTH J24189025 1 B e2 R 2026 CHIP RES 1k 1 16W 5 RMC1 16S 102JTH J24189025 1 B e2 R 2027 CHIP RES 1k...

Page 45: ...6S 154JTH J24189051 AUS 1 B b2 R 2084 CHIP RES 150k 1 16W 5 RMC1 16S 154JTH J24189051 EXP 1 B b2 R 2084 CHIP RES 100k 1 16W 5 RMC1 16S 104JTH J24189049 USA 1 B b2 R 2085 CHIP RES 100k 1 16W 5 RMC1 16S...

Page 46: ...G 6 Parts List PANEL Unit FT 7900R E Technical Supplement REF DESCRIPTION VALUE V W TOL MFR S DESIG VXSTD P N VERS LOT SIDE LAY ADR Note...

Page 47: ...ayout REF DESCRIPTION VALUE V W TOL MFR S DESIG VXSTD P N VERS LOT SIDE LAY ADR Side A SideB Parts List PCB with Components CB2350001 Printed Circuit Board AH016M000 FR0111900 1 J 3001 CONNECTOR NTC 6...

Page 48: ...H 2 FT 7900R E Technical Supplement Note CH Unit...

Page 49: ...FT 7900R E Technical Supplement...

Page 50: ...FT 7900R E Technical Supplement Copyright 2011 VERTEX STANDARD CO LTD All rights reserved No portion of this manual may be reproduced without the permission of VERTEX STANDARD CO LTD...

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