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Circuit Description 

livery  to  the  modulator  on  the  VCO  Unit.  If  an 

external microphone is used, PTT switching is con­

trolled by Q2008 

(1 MZ1 

), which signals the micro­

processor when the impedance at the microphone 
jack  drops. 

If 

VOX  is  enabled, a  sample  of  the 

output  of  the  IDC  stage  is  used  to  activate  the 
transmitter via Q2010 

(DTC124TU). 

If 

Tone Burst or DTMF is enabled for transmis­

sion, the  tone  is  generated  by  microprocessor 
Q2007  and  mixed  with  transmitter  audio  at  the 
IDC stage. Also, the tone is passed via Q2011 

(28C-

4215Y) 

to the Motherboard for output to the loud­

speaker, as mentioned above. The microprocessor 

also  disables  microphone  input  to  Q2009  via 
Q2012 and 02008, and modulator input via Q1003 

(DTC144EU) 

when transmission is disabled. 

The modulating audio is delivered via modula­

tion level trimmer VR1001 on the Motherboard to 

diode 06005 

(188300) 

on the PLL Unit, frequency 

modulating the PLL carrier up to± 5 kHz from the 
unmodulated carrier at the transmitting frequency. 

Also, if a CTCSS tone is generated by the optional 

FfS-17 A Unit, it 

is 

buffered by Q1001 

(28C4116-

GR) 

on the Motherboard, and delivered to the PLL 

Unit  with the  modulating  audio.  The modulated 

signal  from  transmitter  VCO  Q6002 

(28C4226-

R22) 

is  buffered  by  Q6005 

(28C4226-R22) 

and 

delivered to the Motherboard for amplification by 

Q1002 

(28C3120), 

and final  amplification  by  PA 

module Q1007 

(M67748). 

The transmit signal then 

passes through 1/4-wave antenna switch 01011 and 
a 3-pole  lowpass  filter to  suppress non-harmonic 
radiation before delivery to the antenna. 

Automatic  Transmit  Power Control 

RF 

power  output  from  the  final  amplifier  is 

sampled  by  C1053  and  C1060, and  rectified  by 

01017 

(188321 

). The resulting DC is delivered to 

high/low power controller Q4004 

(FM81) 

on  the 

APC Unit, which  selects  high or two low power 
levels  via  Q4003 

(28A 1586Y) 

and  Q4005 

(DTC-

124 TU), 

controlled  by  the  microprocessor  via 

Q2012 on the Control Unit. The output of Q4004 is 

inverted by Q4002 

(28C4116GR), 

and passed by 

Q4001 

(288799-ML) 

back to the input of final am­

plifier Q1007 on the Motherboard, to regulate the 
drive  level  via  Q1018 

(8N1 L4M) 

under  varying 

antenna loading conditions and power level selec­
tion. 

If 

the PLL is unlocked, or while receiving, the 

INH  line  causes  the  ULT5  line  to  be  raised  via 
Q4008 

(DTC144EU), 

Q4006 

(FMW1) 

and  Q4007 

(288799-ML), 

which biases the final amplifier off 

and disables  the front  panel keys  via  Q2014 

(1 M-

86) 

on the Control Unit. 

Spurious Suppression 

Generation  of  spurious products by the  trans­

mitter  is  minimized  by  the  fundamental  carrier 

frequency being equal to the final transmitting fre­

quency, modulated directly in the transmit VCO. 
Additional harmonic suppression is provided by a 

lowpass  filter  consisting  of  L1006, L1008, L1010 
and C1052, C1057, C1059, C1061 and C1066 on the 

Motherboard, resulting  in  more  than  60  dB  har­
monic suppression (for transmitting frequencies in 

the amateur band) prior to delivery to the antenna. 

PLL Frequency Synthesizer 

PLL circuitry on the PLL Unit consists of sepa­

rate transmit and receive VCOs (Q6002 and Q6003, 
both 

28C4226-R22) 

and PLL subsystem IC Q6007 

(MB1504PF-G-BND), 

which  contains  a  swallow 

counter, reference oscillator 

divider, serial-to-par­

allel data latch, programmable divider and a phase 

comparator. 5-V regulator Q1006 

(LM2931AZ-5.0) 

on  the  Motherboard  and  filter  Q6008 

(28C4116-

GR) 

provide the necessary stable supply voltage, 

and temperature compensating capacitors associ­

ated  with  12.8-MHz  frequency  reference  crystal 

X7001 on the Clock Unit provide a stable reference 

frequency. 

Receiver  VCO  Q6003  oscillates  between  122.3 

and 132.3 MHz according to the programmed re­

ceiving frequency. The VCO output  is buffered by 

Q6005 

(28C4226-R22), 

and a sample of the output 

is  buffered by Q6006 

(28C4215Y) 

for application 

to  the  prescaler 

swallow  counter  section  of  the 

PLL chip. There the VCO signal is divided by 64 or 
65, according to a control signal from the data latch 

section of Q6006, before being applied to the pro­

grammable divider section of the chip. 

The  data  latch  section  of  Q6006  also  receives 

serial dividing data from microprocessor Q2007 on 

the  Control  Unit,  which  causes  the  predivided 

VCO signal to be further divided by either 19,568 
- 21,168  or  24,460- 26,460  in  the  programmable 
divider  section, depending  upon  the  desired  re­

ceive frequency, so as to produce a 5-kHz or 6.25-

kHz  derivative  of  the  current  VCO  frequency. 

Meanwhile, the reference divider section of Q6006 

divides  the  12.8-MHz  crystal  reference  from  the 
Clock Unit by 2560 (or 2048) to produce the 5-kHz 

(or 6.25-kHz) loop reference (respectively). 

The  5-kHz  (or  6.25-kHz)  signal  from  the  pro­

grammable  divider  (derived  from  the  VCO)  and 

that  derived  from  the  crystal. are  applied  to  the 

phase detector section of Q6006, which produces a 

dual  5-V  pulsed  output  with  pulse  duration  de­
pending on the phase difference between the input 

signals. This pulse train is passed to the Clock Unit 

FT-26 Technical Supplement 

Summary of Contents for FT-26

Page 1: ...FT 26 TECHNICAL SUPPLEMENT YAESU MUSEN CO LTD C P O BOX 1500 TOKYO JAPAN YAESU U S A 17210 Edwards Rd Cerritos Californi 9fY701 U S A YAESU EUROPE B V Snipweg 3 1118AA Schiphol The NETHERLANDS...

Page 2: ......

Page 3: ...ol CNTL Schematic Diagram 5 13 IF Unit Parts List 5 14 IF Unit Board Layout 5 18 IF Unit Schematic Diagram 5 19 APC Unit Parts List 5 20 APC Unit Board Layout Schematic Diagram 5 22 VR Unit Parts List...

Page 4: ......

Page 5: ...the flat cable socket Pry up on each side of the flat cable socket Fig 1 Fig 3 until you can pull the cable free Then fold the front half to the right Figure 4 D The IF Unit can be removed from the re...

Page 6: ...b SCREW LIST PartNo Descripti on U9900004 TAPTITE SCREW M2X4 U9900012 TAPTITE SCREW M2X4 U9900023 TAPTITE SCREW HM2X4 U00103001 PAN HEAD SCREW M2X3 U07240101 PAN HEAD SCREW M2X4 1 U20203027 BINDING HE...

Page 7: ...i p A02850001 FNB 25 A02880001 FNB 28 Packaging Warranty RegistrationCard E02531000 Operating Manual V1516240 P adding Sheet 09500012 NC 18B 09500013 NC 18C 09500028 NC 28B V1806630 P adding V0516280...

Page 8: ......

Page 9: ...0 L w 3 2 1 6 2 0 1 25 1 6 0 8 Unit mm T 0 45 0 iO 0 35 0 50 0 65 0 95 G 4 0V J 6 3V A lOV Examples c 16V J475 6 3V 4 7 F Type RMC 1 IOW 1 16W Marking I00 222 473 D 20V E 25V v 35V Unit mm 1 1 473 1 1...

Page 10: ...01 001 3001 3005 3007 301 1 3015 4002 6008 2504245 01015 2504215 02011 3002 6006 25A1586 04003 6009 GAT DRAIN SOURCE 25J125 0301 6 25K880 06001 if J SOU CE _ GATE DRAIN 25K882 01008 OLLECTOR BASE 2587...

Page 11: ...2006 1SS300 02016 6005 CATHODE 1SS294 03002 02CZ2 0X 01003 CATHODE 1 AN ODE 2 1 CATHODE 2 ANODE I 1SS302 01007 1018 2001 2009 3001 3003 CATHO DE J ANODE NC SLM 13 02012 2014 CATHOD A HO _ ANODE I ANOD...

Page 12: ...N otes 2 4 F T 2 6 Ti e c hn 1 ca l S u i e m en t...

Page 13: ...before detection of the speech by ceramic discriminator CD3001 Detected audio is de emphasized and filtered by Q3007 and Q3011 2SC4116GR x 2 and then passed through audio muting gate Q3016 2SJ 125D Th...

Page 14: ...the front panel keys via Q2014 1M 86 on the Control Unit Spurious Suppression Generation of spurious products by the trans mitter is minimized by the fundamental carrier frequency being equal to the f...

Page 15: ...rger Power Control The EXT DC jack on the Motherboard applies voltage to the B line through diode D1006 to Circuit Description operate the transceiver and through regulator Q1005 288799 ML to the char...

Page 16: ...N otes 3 4 F T 2 6 Ti ec h n1 c al S up w m e il t...

Page 17: ...thorized Yaesu service techni cians realign all circuits and make complete performance checks to ensure compliance with fac tory specifications after replacing any faulty com ponents Those who do unde...

Page 18: ...efore alignment Alignments must only be made with oscillator shields and circuit boards firmly affixed in place Also the test equipment must be thoroughly warmed up before beginning Note Signal levels...

Page 19: ...ated should be 1 6 mV Press FIM SET C C again to deactivate the VOX Receiver Set up the test equipment as shown at the right receiver alignment Sensitivity Interstage Transformers 0 With the transceiv...

Page 20: ...N otes 4 4 F T 2 6 Ti ec h n ic a l S up i em en t...

Page 21: ...IP REG 11181 504 2SC4215 2SC41 160R YO X7001 12 St IHz PLL UNIT Q2007 PLL DATA CPU SV CPU I HD404608B MOD Q2009 3 Q2009 2 LPF Lit I At IP NJM2902M NJM2902M u G KEY 02003 BOARD PD RH5VA37AA 17 7111Hz...

Page 22: ...2uF 16V c 1 025 K40 1 29060 AL ELECTRO CAP CEDSM l C l O lM l OOuF 16V c 1 026 K221 74809 CHIP CAP GRM39B 1 02M50PT O OO luF 50V B c 1 027 K221 74809 CHIP CAP GRM398102M50PT 0 0 0 luF 50V B c 1 028 K2...

Page 23: ...1 70805 CH I P CAP GRM40B 102M50PT O OOluF 50V B c 1 088 K28 1 79001 CERAM I C CAP UP0508102K A O OOluF 50V B c 1 089 K22 1408 1 1 CH I P CAP GRM408104M25PT 0 luF 25V B DST EXP c 1 089 K22 140 8 1 1 C...

Page 24: ...33JATP 33K 1 16W R 1 0 1 2 J24 1 85821 CH IP RES RMC l 1 6 821JATP 820 1 1 6W R 1 0 1 3 J24 1 85680 CHIP RES RMC 1 16 680JATP 68 1 16W R 1 0 14 J24205 1 02 CHIP RES RMC 1 lOT 102J lK 1 l OW R 1 0 1 5...

Page 25: ...P RES C H I P RES C H I P RES CH I P RES C H I P RES C H I P RES C O I L CO I L CO I L CO I L POT POT XTAL XTAL HOLDER 2pcs SH I ELD PLATE HEATS I NK PLATE LEAF SPR I NG MFGR S DES I G VALUE WV TOL V...

Page 26: ...Board Layout J 1 004 3 GND 2 B 1 CHG OUT 26 GND 25 B 24 T SQ 23 22 CPU S 21 IF IN 20 GND 19 AF 18 SQ 5 V 1 7 R 5 1 6 MIC 15 CLONE 14 T DET 13 SAVE 12 n 11 SP 10 GND 9 LOW 1 8 LOW 2 7 UL T 5 6 MOO 5 T...

Page 27: ...L TONE l t l 1 1 t _H u l o l o ov 4 8Vl 0 1 25V B 101 L N I I CPUS 1 f Eg g t o 1 o 4 o lEu 4 8V 13 BV u g gj I j J TsQ1 I ov i 2 rnvl u _ _ _ _ _ _ u _ c 0 7V ILLJ ov 4 av T STB 17 R1004 1 9Vl ID 1...

Page 28: ...78080017 TANTALUM CHIP CAP TEMSVAOJ475M 8R 4 7uF 6 3V c 2020 K78080017 TANTALUM CHIP CAP TEMSVAOJ475M 8R 4 7uF 6 3V c 202 1 K22144803 CH I P CAP GRM39B 103K25PT O O luF 25V B c 2022 K22140811 CH I P C...

Page 29: ...J 2001 P1090682 CONNECTOR lOFM 1 08P MC2001 M3290014 M I C ELEMENT EM 78C4 Q 2001 G1090906 I C TC4S71F TE85R Q 2002 G3070026 TRANS I STOR I MD2 T108 Q 2003 G1091223 I C RH5VA37AA T l Q 2004 G3070064...

Page 30: ...C H I P RES RMC l 1 6 1 24JATP 1 20K 1 1 6W R 2038 J24 1 85 1 54 C H I P RES RMC l 1 6 1 54JATP 1 50K 1 1 6W R 2039 J24 1 85 1 03 C H I P RES RMC l 1 6 103JATP l OK 1 1 6W R 2040 J24 1 85472 C H I P R...

Page 31: ...IP RES RMC l 1 6 103JATP l OK 1 1 6W R 2073 J24 1 85 1 03 CHIP RES RMC l 1 6 103JATP l OK 1 1 6W R 2074 J24 1 85 1 02 CH IP RES RMC l 1 6 1 02JATP lK 1 16W R 2075 J24 1 85000 CHIP RES RMC l 1 6 OOOJAT...

Page 32: ...NODE I A NODE 3 _ A NODE ll l DD OUT RH5VA37AA 07 02003 CATHODE I CATHODE 2 CATHODE 3 IMNl 0 Nl O 02003 1SS301 83 02008 SLM 23VMWS 02013 1SS300 A3 02016 1 2 GND l l B IO TSQ 9 8 CPU 5 7 ENC 6 ENC 5 A...

Page 33: ...iagram C2013 0 0047 B 1 1 m uo N rl It j 1 1 o ool ar 0 BT2001 Q9000554 R2026 5 61 02007 1SS319 Q20 1 1 R200 2SC421 SY NOTE1 RESI STOR VALUES AAE I N O t 16W 1 CAPAC I TOR VALUES ARE IN F SOV I ffi CA...

Page 34: ...P GRM39B 10 3M25PT O O l uF 25V B c 3026 K22 1 74809 C H I P CAP GRM39B 102M50PT O OO luF 50V B c 3027 K22 144802 C H I P CAP GRM39B 1 03M25PT O O l uF 25V B c 3028 K22 1 748 1 2 CH I P CAP GRM39B 1 8...

Page 35: ...I P RES RMC l 1 6 564JATP 560K 1 16W R 30 1 5 J24 1 85 1 82 CH I P RES RMC l 1 6 1 82JATP 1 8K 1 16W R 30 1 6 J24 1 85821 CH I P RES RMC l 1 6 821JATP 820 1 1 6W R 30 1 7 J24 1 85 1 53 CH I P RES RMC...

Page 36: ...RES RMC l 16 1 03JATP lOK 1 1 6W R 305 1 J24 1 85 1 03 CH IP RES RMC l 1 6 1 03JATP l OK 1 1 6W R 3052 J24 1 85334 CH I P RES RMC l 16 334JATP 330K 1 1 6W R 3055 J24205272 CH I P RES RMC l l OT 272J...

Page 37: ...l Jotes 5 1 7 _ F T 2 6 Ti e c hn 1 ca l S u le m e n t...

Page 38: ...BASE DTC1 44EU 26 03003 3008 301 0 301 2 301 3 2SC41 1 6GR LG 03001 3005 3007 301 1 301 5 2SC421 5Y OY 03002 FT 26 Technical Supplement Tr EM ITTER Tr BASE Tr2 COLLECTOR Tr COLLECTOR Tr2 BASE Tr2 EMIT...

Page 39: ...3028 47K R3045 220K C3042 f o VR3001 220i ov I 0 a ov ov Q3016 2SJ125D ov 0 N 0 a 4 BV N N m N 0 0 I u 0 9V 1 1 1 C3036 1001 tOV ov 4 BV m Ul Igg u 0 ov C3046 O CEi 7 R3048 1 00K I ov 48V ov 4 BV 1 0V...

Page 40: ...L Q 4008 G307004 1 TRANS I STOR DTC 144EU T 1 07 R 400 1 J24 1 85332 CH I P RES RMC l 16 332JATP 3 3K 1 1 6W R 4002 J24 1 8 5 1 02 CH I P RES RMC l 16 102JATP lK 1 1 6W R 4003 J24 1 85223 CH I P RES R...

Page 41: ...N otes 5 21 F T 2 6 Te c h n1 c al S up ie m e t...

Page 42: ...chematic Diagram obverse view of chip only side OLLECTOR BA SE 2SB799 ML 04001 4007 F 3 2 1 2 1 0 2 A J _ OOl OOl am en N C4001 0 001 B lO N 0 0 u Q4003 2SA1586Y NOTE 0 ON a RESISTOR VALUES ARE I N A...

Page 43: ...G VALUE WV TOL VERS VR UN I T CS09980 0 1 P C B W COMP F32 1 1000 P C B W 0 COMP s 5001 Q9000442 ROTARY CODE S W EC09P20 04 VR5001 J60800 1 73 POT RK097 20K SW A VR5002 J60800 1 74 POT RK097 1 1 1 0...

Page 44: ...N otes 5 24 F T 2 6 Te c h m ca l S up k m e nt...

Page 45: ...chematic Diagram Z Z IJ LL w w obverse view of component side obverse view of solder side r F 32 1 1 ooo VR500 1 2 20KA SW POW VR5001 1 20KA SW VOL S5001 EC09P20 04 VR5002 SOKB 2 GND I SQL VR 5 25 T 2...

Page 46: ...LUM CH I P CAP CH I P CAP CH I P CAP CH I P CAP CH I P CAP CH I P CAP CH I P CAP D I ODE D I ODE D I ODE D I ODE D I ODE CONNECTOR CONNECTOR CONNECTOR CH I P CO I L M RFC M RFC FET TRANS I STOR TRANSI...

Page 47: ...P RES CH I P RES CH I P RES CH I P RES CH I P RES CH I P RES CH I P RES CH I P RES CH I P RES CH I P RES CO I L CO I L TP N I PS 1 0 9 1 TP N I PS 1 0 9 1 XTAL HOLDER SH I ELD CASE SH I ELD COVER ASS...

Page 48: ...1 A T6002 L0022 1 09 T6001 L00221 1 0 C6002 220P CH NOTE R6002 1 00K Q6001 2SK880GR RES I STOR VALUES ARE I N 0 1 1 6W CAPAC I TOR VALUES ARE I N F 50V TI CAPAC I TOR VALUES ARE TANTALUM I NDUCTOR VA...

Page 49: ...F 1Q2 l OuF 6 3V c 7004 K22 1408 1 1 CH I P CAP GRM408 104M25PT 0 luF 25V 8 c 7005 K22 1408 1 1 CH I P CAP GRM4081 04M25PT 0 luF 25V 8 L 7001 L 1690055 C O I L 32CS 380HB 221K P 220uH R 700 1 J24 1 85...

Page 50: ...N otes 5 3o F T 2 6 Ti ec h m c al S up le m e t...

Page 51: ...A I NOTE L7001 220p RES I STOR VALUES ARE I N Q l 16W CAPAC I TOR VALUES ARE I N F 50V m CAPAC I TOR VALUES ARE TANTALUM 1 I NDUCTOR VALUES ARE I N H UNLESS OTHERW I SE NOTEO X7001 1 2 BOOllHZ I I I...

Page 52: ...B102M50PT O OO luF 50V B c 8 1 02 K221408 1 1 CH I P CAP GRM40B1 04M25PT 0 luF 25V B c 8 1 03 K221 74223 CH I P CAP GRM39CH330J50PT 33pF 50V CH c 8 1 04 K221 74225 CH I P CAP GRM39CH390J50PT 39pF 50V...

Page 53: ...N otes 5 33 F T 2 6 Ti ec h n1 c al S up w m e t...

Page 54: ...der side TC35305F 08101 1 I F 3 2 3 7 1 0 1 I I I I I I 0ND 1 ov 04 03 02 0 1 DE PO Q81 0 1 TC35305F 1 1 AF le I I I I I m I eo o I 01 NOTE I RESI STER VALUES ARE I N A 1 16W I I CAPAC I TOR VALUES AR...

Page 55: ...soft case if used and the battery pack CTCSS Tone Frequency Hz 67 0 1 00 0 1 41 3 203 5 71 9 1 03 5 1 46 2 2 1 0 7 74 4 1 07 2 1 51 4 2 1 8 1 77 0 1 1 0 9 1 56 7 225 7 79 7 1 1 4 8 1 62 2 233 6 82 5 1...

Page 56: ...0 COMP CH I P CAP GRM39B22 1M50PT 220pF 50V B CH I P CAP GRM39B221M50PT 220pF 50V B CH I P CAP GRM40B 104M25PT 0 l uF 25V B TANTALUM CH I P CAP F95 1 C 1 05MRAAF 1 Q2 l uF 1 6V TANTALUM CH I P CAP F9...

Page 57: ...e view of solder side 22 MX365LH 001 01 l i 1 0 1 F3220 1 00 C 1 05 0 47 25V T C 1 06 4 7 6 3V T NOTE Q 1 0 1 MX365LH C 1 04 1 1 6V T RES I STER VALUES ARE I N 0 1 T GW 1 CAPAC I TOR VALUES ARE I H F...

Page 58: ...BNFOUF NFSBNFOUF QFMP QSB FS EF GB F MP BTP WPDF RVFJSB BKVEBS DPN NBOVBJT JOTVNPT F BUF NFTNP VNB NFSSFRVJOIB QSB BKVEBS OB DPOUB EF MV F OB NBOVUFO P EB NBRVJOB FOUSF FN DPOUBUP QFMP FNBJM BMFYBOESF...

Page 59: ...Copyright 1 99 1 Yaesu Musen Co Ltd All rights reserved Printed in Japan YAE SU v E02539000 1 1 1 e 0K No portion of this manual may be reproduced without the permi ss ion of Yaesu Musen C Ltd...

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