This is a lot of information about FT-736 of YAESU I wait to enjoy this ******************************************************************************* JAS>NO. DATE UTC FROM TO SUBJECT 0111 01/01 09:36 JA6FTL ALL Auto freq. track for UO-14. Auto freq. track for UO-14. ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Auto UO-14 RX frequency tracking for TS-790/FT-736 ------------------------------------------------------ The doppler shift range in overhead pass reaches to 20kHz. It is essential to tune-in RX frequency for good through put. I assembled auto freq. tracking for UO-14 FSK signal reception and achieved good result. [Block diagram] RX discri.out<-- voltage comparater--INV--NOR--switching TR---> Down control (Q1) (Q2) (Q2) (Q3) | G3RUH board DCD ----------------------- [Circuit connection table.] GND Q1:LM324 or TL084 Q2:74HC02 Q3:2SC945 etc. | (C:0.01) | ---- ----- ---- ----- *a<-(R:1M)--------3 Q1 1----6 Q2 4----3 Q2 1---(R:470)---B Q3 C---> DWN *c +12V--(R:8k)--- 2 | -5 | -2 | -E | | ---- | ----- | ---- | ---- | | | | (VR:10K) GND | GND | | GND | GND +12V +5V *b<-- G3RUH board DCD line------------ Q1 11 4 Q2 7 14 *a: to RX discri out (=G3RUH board RX IN) *b: to G3RUH board DCD line (U10 pin 13) *c: to down control pin of mic terminal (TS-790 mic pin 3) setting of VR:10k The discriminator IC output level is 5.8V+-2V. Whitout RX signal, set the VR to Q1 pin 1 level turn HIGH->LOW. In my case, I assembled the circuit on a small universal PCB and enclosed into TINY-2 with NB96 board. In the case of FT-736, DL signal polarity is different from TS-790 so change as follow ------ 3 Q2 1------|>------> DL signal to mic terminal 2 | Diode (1S1588 etc) ----- 73s sueo asato JA6FTL Posted at 18:38:41 12/23/90 JAS> ******************************************************************************* NO. DATE UTC FROM TO SUBJECT 0837 01/11 09:11 JA6FTL ALL FT736R mod. to 9.6kbps This short note was uploaded to CI$ HAMNET Lib. I think it is usefull for those who intend to try 9.6kbps with FT-736. de JA6FTL 1-1-1991 ------------------------------------------------------------------------- Posted: Sun, Mar 18, 1990 6:23 PM GMT Msg: EGJA-4199-1763 From: UOSAT To: AMSAT Subj: FT736R/9600/FO-20/PACSAT Mods Dumped on 16 Mar 90 23:57:08 Friday by ELE093 From: JAMES MILLER G3RUH via TMAIL Address: UOSAT Date: 1990 Mar 16 ===== ------------------------------------------------- FT736 & 9600 Baud Operation --------------------------- by James Miller G3RUH These notes tell you where to get FM RX audio direct from the discriminator, and where to modulate the FM TX varactor directly. These mods are non-destructive and take no more than a few minutes. The signal bypass the "DATA SOCKET" for high grade FM operations. The RX mod is suitable for: * UOSAT-D 9600 baud downlink and terrestrial links * 1200 baud AFSK/FM Standard Packet - BUT IT'S UNSQUELCHED. The TX mod is suitable for: * FO-20/PACSAT uplink (1200 bps Manchester FM) * UOSAT-D 9600 baud uplink direct FSK and terrestrial links * 1200 baud AFSK/FM Standard Packet. ---****--- FT736 - FM Direct from Discriminator ------------------------------------- Detected FM direct from the receiver discriminator is available from the RX UNIT at the junction of R91 and C83. These components are shown in the top right-hand corner of the schematic. Proceed thus: 1. Disconnect FT736 from the mains electricity. (Safety). 2. Remove top cover only. 3. RX Unit is the vertical module on the left. 4. Locate R91 which is about 25mm from the top, 50mm from the radio rear. the resistor is "on-end", and near a couple of glass diodes. 5. Scrape any paint off R91's free end and wet with solder. 6. Your RXaudio lead should be a fine screened cable; connect the inner to R91, and the outer braid to a ground point (e.g. can of TO09) 7. Route the cable out though any convenient aperture in the case. 8. The discriminator sensitivity (FM Normal) as about 6 kHz/volt. Important note on 9600 Baud Use ------------------------------- Some FT736 receivers are fitted with an LFH12-S IF filter for FM. (CF01 at the top front of the RX Unit). This is a 12 kHz bandwidth filter which is a little too narrow for 9600 bps FSK operation. It is recommended you change this to 15 kHz or better still for UOSAT-D use, 20 kHz bandwidth which will allow more tolerance for doppler shift, and give a far better "eye". Suitable filters are: LFH-15S or CFW455E, and LFH-20S or CFW455D. The first of these is a Yaesu spare part, and is often already fitted. ---****--- FT736 DIRECT VARACTOR FM MODULATION ------------------------------------ Refer to the circuit diagram; inject your TXaudio at the junction of R32/C29 on the TX Unit. The signal level at this point should be 800 mV peak-peak, and will give +/- 3 kHz deviation. DO NOT EXCEED THIS LEVEL. Set Mic Gain to min. Modulating the FM transmitter this way you get an LF response down to 18 Hz (at which point the associated synthesiser PLL begins to track the modulation), and an HF response which is flat to some 10 kHz. Proceed thus: 1. Disconnect FT736 from the mains electricity. (Safety). 2. Remove top cover only. 3. TX Unit is the module flat on the left (not the one tucked down the side vertically). 4. R32 is just to the left of the rectangular shielded enclosure. The resistor is "on end". Scrape any paint off the free leg. 5. Your TXaudio lead should be a fine screened cable; connect the inner to R32, and the outer braid to the adjacent enclosure. 6. Route the cable out though any convenient aperture in the case. 7a. 1200 BAUD PSK MODEM: TXAudio of 800 mV pk-pk can be obtained by adjusting the components C9= 1uf, R3=47k, R5=infinity (i.e. remove). C10 stays at 10nf (0.01uf). 7b. 9600 BAUD FSK MODEM: Adjust TXAudio level with VR1 Notes compiled by G3RUH @ GB7SPV 1990 Mar 16 ------end------ JAS> ******************************************************************************* JAS>NO. DATE UTC FROM TO SUBJECT 0489 05/29 09:37 G3RUH ALL FT736R CAT Interface Drivers Here are some routines to drive a Yaesu FT736R CAT interface. Note that the radio has TTL levels, so you need to build a circuit to convert RS232 voltages to TTL voltages. You can do this with a MAX231 etc, or a couple of NPN transistors. The latter can be mounted inside your DB25 connector. 1. The Yaesu spec contains one or two typos which are herein connected. 2. It does not appear to be necessary to space out the 5 control bytes by 50 ms. 3. The READ S-meter, squelch functions smetimes fail to return all 5 bytes, so the code (FNget) accomodates this. REM REM FT736R CAT Interface Drivers REM ---------------------------- REM Last modified 1990 May 21 REM REM (C)1990 J R Miller G3RUH REM REM Procedures and functions available are: REM REM PROCcat(on|off) REM PROCmode(lsb|usb|cw|cwn|fm|fmn) REM PROCptt(on|off) REM PROCsplit(off|plus|minus) REM PROCoffset(MHz) REM PROCfreq(MHz) (* e.g. MHz = 145.6789 etc *) REM PROCfull_dup(on|off) REM PROCsat_mode(tx|rx , lsb|usb|cw|cwn|fm|fmn) REM PROCsat_freq(tx|rx , MHz) REM FNsqlch (* returns 0 if no signal *) REM FNmeter (* returns S-meter value *) REM REM REM Example - prepare FT736R for FUJI-OSCAR-20 satellite REM ==================================================== PROCset_up: REM Do once only per session! PROCcat(on) PROCfull_dup(on) PROCsat_mode(rx,usb): PROCsat_freq(rx,435.916) PROCsat_mode(tx,fm ): PROCsat_freq(tx,145.850) PROCcat(off) END : REM Now follows procedures and functions : DEF PROCcat(F%) IF F%=on B%(5)=0 ELSE B%(5)=&80 PROCput: ENDPROC : DEF PROCmode(B%(1)) B%(5)=7: PROCput: ENDPROC : DEF PROCptt(F%) IF F%=on B%(5)=8 ELSE B%(5)=&88 PROCput: ENDPROC : DEF PROCsplit(F%) B%(5)=&89: REM simplex IF F%=plus B%(5)=&49 IF F%=minus B%(5)=9 PROCput: ENDPROC : DEF PROCoffset(F) B%(5)=&F9 PROCfr(F) PROCput: ENDPROC : DEF PROCfull_dup(F%) IF F%=on B%(5)=&E ELSE B%(5)=&8E PROCput: ENDPROC : DEF PROCsat_mode(F%,B%(1)) IF F%=tx B%(5)=&27 ELSE B%(5)=&17 PROCput: ENDPROC : DEF PROCfreq(F) B%(5)=1 PROCfr(F) PROCput: ENDPROC : DEF PROCsat_freq(F%,F) IF F%=tx B%(5)=&2E ELSE B%(5)=&1E PROCfr(F) PROCput: ENDPROC : DEF PROCfr(F) IF F>=1000 FX%=on ELSE FX%=off F=(F+0.000005)/1000 FOR I%=1 TO 4: F=F*100: F%=INT(F): F=F-F% B%(I%)=(F% DIV 10)*16 + F% MOD 10 NEXT IF FX%=on B%(1)=B%(1)AND &F + &C0: REM 1200 MHz band corrrection ENDPROC : DEF FNsqlch B%(5)=&E7: PROCput: PROCget IF B%(1)=0 THEN =0 ELSE= -1 : DEF FNmeter B%(5)=&F7: PROCput: PROCget =B%(1) : DEF PROCset_up REM Establish constants etc DIM B%(5) off=0: on=-1 rx =0: tx=-1 plus=+1: minus=-1 lsb=0: usb=1: cw=2: cwn=&82: fm=8: fmn=&88 : REM Most code after this is for controlling the BBC micro hardware REM and needs recoding for any other machine. Note "*FXn,m" is REM merely a BBC micro operating system call, no. n, parameter m. REM REM Set up RS423 = 4800,8,N,2 *FX8,6 *FX7,6 *FX156,16,227 ENDPROC : DEF PROCput REM Procedure sends five bytes to RS432c port, spaced by 50ms REM bytes are in array B%(1) ... B%(5) FOR I%=1 TO 5 REM Delay below is in the spec, but can actually be omitted T%=TIME: REPEAT UNTIL TIME >= T%+5: REM Wait 50 ms/byte REM Now direct output to RS423, o/p char, and restore o/p to screen *FX3,3 VDU B%(I%) *FX3,0 NEXT ENDPROC : DEF PROCget REM Flush RS423 I/P buffer, then read bytes from input stream REM until op code is detected. Previous value is result. REM (straight reading 5 bytes found to be unreliable) *FX15,1 *FX2,1 REPEAT B%(1)=B%: B%=GET: UNTIL B%=B%(5) *FX2,0 ENDPROC : REM End of code REM de G3RUH @ GB7SPV 1990 May 29 JAS> ******************************************************************************* 10 REM =============================================== 20 REM CAT CONTROL FOR YAESU FT-757GX 30 REM ORIGINAL PROGRAM BY: (QST, OCT 1985, P.38) 40 REM KJELL W. STROM, SM6CPI 50 REM MODIFIED FOR THE IBM PC 60 REM BY: (QST, APR 1986, P.41) 70 REM ROBERT G. PIERLOTT, WE4J 75 REM & GEORGE B. FRYER, KI4KK 78 REM MODIFICADO PARA 736 POR PEDRO CONVERSO, LU7ABF 80 REM =============================================== 90 CLS : WIDTH 80: KEY OFF: DEFDBL A-B 105 GOSUB 3000 106 LOCATE 17, 14, 0, 0, 7: PRINT "ENTRAR EL PORT DE COMUNICACIONES QUE SE DESEA USAR. 1 OR 2 ?" 107 C$ = INKEY$: IF C$ = "" THEN 107 108 IF C$ = "1" THEN GOTO 110 109 IF C$ = "2" THEN GOTO 112 ELSE GOTO 107 110 OPEN "COM1:4800,N,8,2,rs,cs,ds,cd" FOR RANDOM AS #1: GOTO 115 112 OPEN "COM2:4800,N,8,2,rs,cs,ds,cd" FOR RANDOM AS #1 115 H% = 16 120 T$ = "" 130 FOR I = 0 TO 9 140 FOR J = 0 TO 9 150 T$ = T$ + CHR$(I * H% + J) 160 NEXT: NEXT 200 CLS 210 LOCATE 5, 16, 0, 0, 7: PRINT " 0: CAT-ON 14: FULL DUPLEX ON" 220 LOCATE 6, 16, 0, 0, 7: PRINT "128: CAT-OFF 142: FULL DUPLEX OFF" 230 LOCATE 7, 16, 0, 0, 7: PRINT " 1: Frec 30: FULL DUPLEX - Frec Recepcion" 240 LOCATE 8, 16, 0, 0, 7: PRINT " 7: Modo 46: FULL DUPLEX - Frec Transmision" 250 LOCATE 9, 16, 0, 0, 7: PRINT "249: Frec.Desplaz Split 23: FULL DUPLEX - Modo Recepcion" 255 LOCATE 10, 16, 0, 0, 7: PRINT "137: Simplex 39: FULL DUPLEX - Modo Transmision" 260 LOCATE 11, 16, 0, 0, 7: PRINT " 73: Transmision arriba 12: QUIT" 265 LOCATE 12, 16, 0, 0, 7: PRINT " 9: Transmision abajo " 270 LOCATE 13, 16, 0, 0, 7: PRINT " 8: Transmitir " 275 LOCATE 14, 16, 0, 0, 7: PRINT "136: Recibir " 300 LOCATE 17, 27, 0, 0, 7: COLOR 14, 1: INPUT "Entre su Seleccion "; C 305 COLOR 15, 1 310 IF C < 0 OR C > 255 THEN 300 320 M$ = CHR$(C) 330 IF C = 1 OR C = 30 OR C = 46 THEN 1000 335 IF C = 7 OR C = 23 OR C = 39 THEN 4000 337 IF C = 249 THEN 5000 340 IF C = 12 THEN 2000 500 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 501 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 503 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 504 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 505 PRINT #1, M$; 510 GOTO 200 1000 REM FREQUENCY CONTROL 1010 CLS : LOCATE 9, 34, 0, 0, 7 1020 INPUT "FREQUENCY "; FREQ$ 1021 FOR I = LEN(FREQ$) TO 7: FREQ$ = FREQ$ + "0": NEXT I 1022 A = VAL(FREQ$) 1025 A$ = STR$(A) 1030 ' IF A < 50000! OR A > 2999999! THEN 1010 1040 GOSUB 1800 1050 CLS : LOCATE 3, 31, 0, 0, 7: PRINT "New Frequency = F" 1070 LOCATE 10, 34, 0, 0, 7: PRINT "Fine Tuning:" 1080 LOCATE 12, 30, 0, 0, 7: PRINT "<<< --- KHz --- >>>" 1090 LOCATE 14, 34, 0, 0, 7: PRINT USING "###,###.## \ \"; (A / 100), "MHz" 1100 LOCATE 16, 16, 0, 0, 7: PRINT "1Mc 100 10 1 .1 .01 .01 .1 1 10 100 1Mc" 1110 LOCATE 17, 16, 0, 0, 7: PRINT " A Z X C V B N M , . / '" 1120 C$ = INKEY$: IF C$ = "" THEN 1120 1125 IF ASC(C$) = 13 THEN 200 1130 IF C$ = "B" OR C$ = "b" THEN A = A - 1: GOTO 1300 1140 IF C$ = "N" OR C$ = "n" THEN A = A + 1: GOTO 1300 1150 IF C$ = "V" OR C$ = "v" THEN A = A - 10: GOTO 1300 1160 IF C$ = "M" OR C$ = "m" THEN A = A + 10: GOTO 1300 1170 IF C$ = "C" OR C$ = "c" THEN A = A - 100: GOTO 1300 1180 IF C$ = "," THEN A = A + 100: GOTO 1300 1190 IF C$ = "X" OR C$ = "x" THEN A = A - 1000: GOTO 1300 1200 IF C$ = "." THEN A = A + 1000: GOTO 1300 1210 IF C$ = "Z" OR C$ = "z" THEN A = A - 10000: GOTO 1300 1220 IF C$ = "/" THEN A = A + 10000: GOTO 1300 1230 IF C$ = "A" OR C$ = "a" THEN A = A - 100000!: GOTO 1300 1240 IF C$ = "'" THEN A = A + 100000!: GOTO 1300 1250 IF C$ = "F" OR C$ = "f" THEN 1010 1260 IF C$ = "O" OR C$ = "o" THEN 200 1300 A$ = STR$(A): ' IF A < 50000! OR A > 2999999! THEN 1010 1310 GOSUB 1800 1315 LOCATE 14, 34, 0, 0, 7: PRINT USING "###,###.## \ \"; (A / 100), "MHz" 1320 GOTO 1120 1800 REM *************************************** 1801 REM SUBROUTINE TO WRITE FREQUENCY TO FT-736 1802 REM *************************************** 1803 A$ = STR$(A) 1804 B$ = RIGHT$(A$, 8) 1810 F1% = VAL(MID$(B$, 1, 2)) 1820 F2% = VAL(MID$(B$, 3, 2)) 1830 F3% = VAL(MID$(B$, 5, 2)) 1840 F4% = VAL(MID$(B$, 7, 2)) 1850 G1$ = MID$(T$, F1% + 1, 1) 1860 G2$ = MID$(T$, F2% + 1, 1) 1870 G3$ = MID$(T$, F3% + 1, 1) 1880 G4$ = MID$(T$, F4% + 1, 1) 1890 PRINT #1, G1$; : FOR Z = 1 TO 45: NEXT Z 1891 PRINT #1, G2$; : FOR Z = 1 TO 45: NEXT Z 1892 PRINT #1, G3$; : FOR Z = 1 TO 45: NEXT Z 1893 PRINT #1, G4$; : FOR Z = 1 TO 45: NEXT Z 1894 PRINT #1, M$; 1900 RETURN 2000 LOCATE 15, 33, 0, 0, 7: COLOR 30, 1: PRINT "Seguro? ": COLOR 15, 1 2001 C$ = INKEY$: IF C$ = "" THEN 2001 2010 IF C$ = "S" OR C$ = "s" THEN CLOSE : CLS : END 2020 GOTO 200 2030 END 3000 REM TITLE SCREEN 3005 COLOR 1, 7: CLS 3010 LOCATE 1, 27, 0, 0, 7: PRINT "C A T P R O G R A M P A R A" 3020 LOCATE 3, 27, 0, 0, 7: PRINT " Y A E S U F T - 7 3 6 G X" 3030 LOCATE 5, 22, 0, 0, 7: PRINT "ORIGINAL FOR FT-737, BY KJELL W. STROM, SM6CPI" 3033 LOCATE 7, 16, 0, 0, 7: PRINT "MODIFIED FOR IBM PC BY ROBERT G. PIERLOTT, WE4J" 3038 LOCATE 11, 18, 0, 0, 7: PRINT "MODIFICADO PARA FT-736 POR PEDRO CONVERSO, LU7ABF" 3245 COLOR 15, 1 3270 RETURN 4000 CLS : LOCATE 8, 16, 0, 0, 7: PRINT "Para: USB LSB CW FM CW-Angosto FM-Angosto" 4010 LOCATE 9, 16, 0, 0, 7: PRINT "Entrar: 0 1 2 8 130 136 " 4020 LOCATE 14, 27, 0, 0, 7: COLOR 14, 1: INPUT "Entre su Seleccion "; S$ 4025 IF S$ = "" THEN 200 ELSE S = VAL(S$) 4030 G1$ = CHR$(S): G2$ = CHR$(0): G3$ = CHR$(0): G4$ = CHR$(0) 4040 GOSUB 1890: GOTO 4000 5000 REM SHIFT DE FRECUENCIA 5010 CLS : LOCATE 9, 26, 0, 0, 7 5020 INPUT "FREQUENCY SHIFT IN Kc "; FREQ$ 5021 FREQ$ = "00000000" + FREQ$ + "00": FREQ$ = RIGHT$(FREQ$, 8) 5022 'A=VAL(FREQ$) 5025 A$ = FREQ$ 5100 GOSUB 1804 5110 GOTO 200 6000 'TEST S-METER 6010 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 6020 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 6030 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 6040 PRINT #1, CHR$(0); : FOR Z = 1 TO 45: NEXT Z 6050 PRINT #1, CHR$(247): FOR Z = 1 TO 45: NEXT Z 6060 GET #1, C 6070 LOCATE 20, 34, 0, 0, 7: PRINT C; : RETURN ******************************************************************************* ubject: FT-736R SAT SWITCH CAN ZAP PREAMPS Path: N8GTC!NK8T!KF4NB!K3VYY!K4EID!N4SZO The FT-736R SAT switch can zap pre-amps. The 736R SAT switch has break-before-make contacts, which means that in between switch positions the circuit is the same as if the SAT switch is in the OFF position. If you have set up one of the modules to transmit for non-satellite operations (i.e., w hen SAT switch is OFF), that module will be enabled between the RX-TX-NOR-REV positions of the SAT switch. If you are transmitting while you move the SAT switch between these positions you may accidently key up the unintended module and send a burst of RF down the antenna line into your pre-amp. For example: VFO A happens to be set to operate on 2 meter FM. You don't give this a second thought, since you are working Mode B CW with the SAT switch ON. You are listening on 2 meters and keying your 70 CM transmitter trying to zero your downlink f requency. Changing the SAT switch positions under these conditions is perfectly normal. However, if you happen to send a dot or dash during the open interval between switch positions it is not your 70 CM transmitter that gets keyed but your 2 meter FM transmitter. This sends a burst of RF down the 2 meter coax that you have configured for receiving. If you have in that coax a preamp without adequate RF-sensed pin-diode switching, then say goodbye to the GaAsFETs in the preamp. If you are using the FT-736R preamp switch and the 12 VDC on the coax to operate coax relays at the preamp, you might be lucky -- if the relays drop out fast enough. I don't know if the control circuits operate fast enough to take care of this transie nt condition, but I doubt it. This cost me two MGF-1402 GaAsFETs in my unprotected homebrew 2 meter preamp before I realized that they both departed this world under exactly the same circumstances of operation of the SAT switch while sending. Although I was on CW, the same thing cou ld happen on SSB if you happened to be speaking and the VOX were to be operated during the switch rotation. Thanks to John, KL7GRF, for clueing me to the real problemhe SAT switch while transmitting. (2) Use adequate RF sensed preamp switching. 73 de Dick, W2GFF @ N4SZO ******************************************************************************* Modification to the Yaesu FT-736R. G4WFQ 12/1/92. This modification was given to me by Zeno Wahl, G0NJC/VE3LMX (U.O.S) The modification lowers the frequency response to 3 HZ, and gives a far better "eye" by reducing L.F flutter. Proceed thus. Locate "TXPLL UNIT" (Vertical board on Tx unit). Locate R01 (Scrape any paint off. Wet component with FINE solder. Solder 560ohm Resistor on R01 (end nearest to pll board) Solder 47micro fara tantalum in series with 560R. Take (-) negative leg of Cap to Gnd, eg case of Txpll unit. End. 73 Dave G4WFQ. ******************************************************************************* JAS> NO. DATE UTC FROM TO SUBJECT 0224 02/23 00:20 G3RUH ALL FO-20 & Yaesu FT736R FO-20 & the Yaesu FT736R --------------------------- by James Miller G3RUH If like me, one of the (many) features that attracted you to the FT736R was the special DATA SOCKET, then you were probably very pleased to read in the manual: "This 3-contact mini stereo jack allows direct connection to the FM receiver demodulator and FM transmitter modulator for digital equipment such as a packet radio TNC. No pre-emphasis or de-emphasis is added to the signals at this jack" (page 14). Don't believe a word of it! A cursory inspection of the circuit diagram shows that the TX side is simply merged with the microphone audio just after the Mic Gain control, and is then murdered by several subsequent filters. On the RX side the data audio output is similarly indirect. My initial day with FO-20 was disastrous. (Yours too?) So I looked at the FM signal on a calibrated monitor receiver when transmitting FO-20/Microsat "Manchester" uplink signals. The waveform was appallingly distorted. The problem is that the TX LF response cuts off at 800 Hz. But the data has substantial energy at 600 Hz and below. Indeed, when transmitting a 600 Hz square wave it was clear from the droop distortion that FO-20 or a Microsat would almost certainly not decode the uplink reliably. The cure is simple; modulate the FM varactor directly. Refer to the circuit diagram; inject your TXaudio at the junction of R32/C29 on the TX Unit. The signal level at this point should be 800 mV peak-peak, and will give +/- 3 kHz deviation. DO NOT EXCEED THIS LEVEL. Set Mic Gain to min. The implementation is simple too. 1. Disconnect FT736R from the mains electricity. (Safety). 2. Remove top cover only. 3. TX Unit is the module flat on the left (not the one tucked down the side vertically). 4. R32 is just to the left of the rectangular shielded enclosure. The resistor is "on end". Scrape the paint off the free leg. 5. Your TXaudio lead should be a fine screened cable; connect the inner to R32, and the outer braid to the adjacent enclosure. 6. Route the cable out though any convenient aperture in the case. [ TXAudio of 800 mV pk-pk can be obtained from the G3RUH PSK modem by adjusting the components C9= 1uf, R3=47k, R5=infinity (i.e. remove). C10 stays at 10nf (0.01uf).] Modulating the FM transmitter this way you get an LF response down to 18 Hz (at which point the associated synthesiser PLL begins to track the modulation), and an HF response which is flat to some 10 kHz. *** FO-20/Microsat uplink modulation is now absolutely perfect. *** G3RUH @ GB7SPV 1990 Feb 23 Amsat Tmail Address "UOSAT" ******************************************************************************* FT736-R piep modification ------------------------- Those who do like to switch the annoying piep from the FT736R during doppler correction can make the following modification: Disassemble the case of the FT736R Unscrew the front panel with the 4 screws on the side. The front panel will turn down. Disconnect the black wire of the sound buzzer that is on the PCB with the computer. Connect the black wire to the right pin of the 3 pin connector that is located on the PCB with the front panel switches completely on the left side. This is a connection to the KEYER switch. You now can switch on - off the buzzer with the KEYER switch if you have no keyer in the transceiver ! Good luck 73's Freddy ******************************************************************************* NO. DATE UTC FROM TO SUBJECT 0556 04/22 15:29 G3KMI ALL FT736 Computer I/F problems. Hello, Again this is a remail of a message I sent about a month ago. Sorry I you have replied allready but the Easter Vacation prevented access to the University Groundstation. I missed any replies therefore. This is the message again: Has anyone else had problems regarding the FT736 Computer Aided Tranceiver (CAT) interface. It seems to be very fussy about timing. The manual suggests that 50-200ms is needed between each information byte, but even with this it is not error free. I can often manage to put it into an unknown state, I suppose by sending data too fast or slow. This can mean that the interface locks up and does not respond or worse, goes into transmit permanently !! Has anyone any thoughts or experience of this ?? If so mail me a message, I would like to discuss the problems with anyone. I have a bit of experience with it if anyone else is having problems. Chris G0KLA ECS Southampton University G3KMI ******************************************************************************* The FT-736R SAT switch can zap pre-amps. The 736R SAT switch has break-before-make contacts, which means that in between switch positions the circuit is the same as if the SAT switch is in the OFF position. If you have set up one of the moduls to transmit for non-satellite operations (i.e., when SAT switch is OFF), that module will be enabled between the RX-TX-NOR-REV positions of the SAT switch. If you are transmitting while you move the SAT switch between these positions you may accidetly key up the unintended module and send a burst of RF down the antenna line into your pre-amp. For example: VFO A happens to be set to operate on 2 meter FM. You don't give this a second thought, since you are woring Mode B CW with the SAT switch ON. You are listening on 2 meters and keying your 70 CM transmitter trying to zero your downlink frequency. Changing the SAT switch positions under these conditions isperfectly normal. However, if you happen to send a dot or dash during the open interval between switch positions it is not your 70 CM transmitter that gets keyed but your 2 meter FM transmitter. This sends a burst of RF down the 2 meter coax that yu have configured for receiving. If you have in that coax a preamp without adequate RF-sensed pin-diode switching, then say goodbye to the GaAsFETs in the preamp. If you are using the FT-736R preamp switch and the 12 VDC on the coax to operate coaxrelays at the preamp, you might be lucky -- if the relays drop out fast enough. I don't know if the control circuits operate fast enough to take care of this transient condition, but I doubt it. This cost me two MGF-1402 GaAsFETs in my unprotected homebrew 2 meter preamp before I realized that they both departed this world under exactly the same circumstances of operation of the SAT switch while sending. Although was on CW, the same thing could happen on SSB if you happened to be speaking and the VOX were to be operated during the switch rotation. Thanks to John, KL7GRF, for clueing me to the real problemhe SAT switch while transmitting. (2) Use dequate RF sensed preamp switching. 73 de Dick, W2GFF @ N4SZO 73's Freddy JAS> ******************************************************************************* 73,s LU1EXC/Jorge  Msg Nr. : 50307 Da : F6EGK Per : YAESU @EU Tipo/status : B$ Data/ora : 1010/0903 Dimensione : 4048 Titolo : FT736 - poor EMC features Bid (Mid) : 08A305LX0PAC de F6EGK @ LX0PAC.LUX.EU to YAESU @ EU FT736R: poor EMC features Hello dear Oms. Here are my experiences with the FT736R, the problems which I have encountered, and the cures that I have found. 1st: background noise given by the switching power unit. This problem occurs on 50 MHz and 144 MHz. By using a spectrum analyzer, I have seen that the power unit radiates a wide bandwidth of noise (can be compared to white noise) between 40 and 42 MHz. The level is high, more than the mean value encountered with a switching PSU built for computer using ! --> the cure: no miracle, the simplest and efficient way is to use an external power supply instead of the built in one... 2nd: overload of the receiver by the path of coaxial cable (between antenna and the TRx). Before introducing the problem, I have to tell that I live not far from a high power broadcast station (medium waves). The first time I have used the FT736R, it has been impossible to hear something on any bands (from 50 MHz to 432 MHz)! I have discovered that the problem comes from the DC sys- -tem used for the supply of the preamps on each band. The DC supply is ensured through the coaxial cable. With high values of RF fields the coaxial cable acts as an antenna. These spurious RF signals come through the DC line called PRE in the FT736R. Note that this problem can be met without any installed preamp or with the front panel push button (PREAMP) in "off" position. --> the cure: quite simple, you have to solder a 0,1 uF on the existing by-pass capacitor for EACH PRE line of all Rx module. That is to say: C32 for all the bands. The originals values for C32 are always 0,001 uF (1 nF). These by-pass capacitors are closed to each PA unit and can be easily found. By increasing the value of each capacitor, you decrease the cut-off frequency of the L11-C32 filter and avoid any problem. 3rd: background noise given by the PTT lines (input PTT jack for data communi- -cation and output PTT STBY DIN jack for the remote of an external power amp- -lifier). My FT736R is put on a wood shelf and under is located a PA unit. I have also a TNC (HK232) which is also connected. At this time, I have remarked background noise mainly on 144 MHz, which is more noticeable when moving optic VFO encoder. These two PTT lines are sensitive to wide frequency signals given by "computer" signals coming mainly from the front panel (display) and uP unit (clocks, hardware bus). --> the cure: the only efficient solution is to put LC filter on each PTT line They can be installed outside of the TRx but rather closed to the rear panel of it. The filter uses the "pi" structure with two 0,1 uF capacitors and a small choke coil about 220-470 uH (not critical value). You have to try seve- -ral choke coils in order to avoid the QRM and also to have a normal PTT function (care of added resistance for DC PTT current given by the choke coil) 73 de Jean-Roger F6EGK @ LX0PAC ============================================================================ Article 15023 of rec.ham-radio: From: gopstein@helix.squibb.com (Rich Gopstein) Newsgroups: rec.ham-radio Subject: FT736 2m RX mod! Date: 15 Jan 91 15:17:09 GMT Sender: news@soleil.UUCP Organization: Bristol-Myers Squibb PRI, Lawrenceville, NJ Lines: 37 I found this on Compuserve. I tried it on my FT736, and it works! I wonder what the other diodes do? Does anyone have a service manual for the FT736? Fm: Chuck Scott N8DNX 76556,3335 You can modify the 2 Meter section for 141-154 MHZ by adding D27 (not installed in USA version). This is normally soldered to the board but you can easily install it by simply shoving the leads into the connector. The 2 Meter section is the middle board looking into the radio from the top. The connector (J09) is the large one on the right side of the board, half way back. You want the cathode (striped end) of a small signal diode in pin 7 and the anode in pin 4. Pin 1 is toward the front of the radio. To receive over a slightly wider range, place the SAT switch in RX mode, press ENT[D] then enter a desired frequency and press ENT[D] again. You can enter any frequency from 100 to 200 MHz this way. Unfortunately, the synthesizer does not actually cover that range. As far as I can tell the bottom end is about 138.5 (not quite the 136.5 needed for the weather sats). The top end is about 155.6. You can't perform this stunt with the normal (non-satellite) VFO's. Also, once a frequency is entered in this way, it is possible to tune toward the normal range but tuning away will place you back in the 141-154 range. Using the same method yields aprox 220.0-229.5 & 423.0-454. You may store these frequencies in the SAT Memories. Chuck -- Rich Gopstein gopstein@squibb.com rutgers!squibb.com!gopstein -- -- James Dugal, N5KNX Internet: jpd@usl.edu Associate Director Ham packet: n5knx @k5arh (land), UO-22 (sat.) Computing Center US Mail: PO Box 42770 Lafayette, LA 70504 University of Southwestern LA. Tel. 318-231-6417 U.S.A. ============================================================================ ========================================================================= Are there any mods for the Yaesu FT736R? I modified mine. There's a catch tho - the mod involves adding a pair of switches to the module-address lines into each of the rf modules..it's kinda funky but it does work. Look at your schematic, then wire up the switches such that your 6m and 2m modules *think* that they're 440MHz modules! The trick then is to look at the display, which reads 443.000, and mentally adding 6.0 such that you know the real frequency is 49.000MHz. Similarly, the display will read 445.000 when the 2m module is really at 145.000. When you finish adding the switches, you'll have to powerup the '736 with the switches in the 'extended range' position. Then use one of your existing memory frequencies, transferred to either the A or B vfo, to then bandswitch up or down to the 440 band. Bingo! If you goof, the display will read "error". Start over by powering down, and then repeat the procedure. Sometimes the frontpanel logic will simply lock, just start over and it will eventually work. Mine never takes more than 2 tries. With the switches in the 'normal range' position the '736 will function as a stocker. The range for the 6m unit is therefore 46-56 MHz, and the 2m unit will give you 140-150 MHz. Yes, the transmitter will also work this span, but keep in mind a 10 watt signal on the 49 MHz band sticks out like a sore thumb! ;-) ("Wow! Listen to *that*! He must have a better walkie-talkie than these RadioShack junkers!") ;-) My attempts to modify the range on the 430 MHz rf module have not meet with much success, and a careful look at the schematics/numbers tell the story quite well; The module covers 430-440, a 10MHz range. Therefore, the address-line trick will yield no more coverage. Have Fun, 73! -- -Avatar-> KB6LUY +-------------------------+ % Note: I haven't tried or verified this, proceed at your own risk! WA2ISE And don't transmit outside your licesned bands! ========================================================================== Msg Nr. : 1770 Da : G0HEG Per : ALL @WW Tipo/status : BF Data/ora : 0220/0259 Dimensione :12876 Titolo : MODS FOR FT736R MOD 1 Bid (Mid) : 50633_GB7WRG MODIFICATION OF THE PMS ON THE FT736R FOR THE 144 TO 148 MHZ BAND MOD 1 BY G0HEG Modification of the PMS on the FT736R for VHF, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 139 MHz to around 155 MHz By the use of the Repeater shift, This gives a coverage of about 16 MHz, There is no need to snip any of the components, And you will not need a soldering Iron for this Modification, Instructions There are Two Mods for the FT736R for VHF, One is for the European Version, Which is the one that we will deal with first, And the other is for the American Version, That we will deal with later on. Important notice Make sure that you are in VFO B when you start this Mod Follow the instructions to the letter. Always put the Highest Frequency into VFO B, and the Lowest ones into VFO A. 1/ Turn on Your RIG. 2/ Put the RIG into Repeater shift for the 144 MHz Band, By Pressing the - RPT KEY. 3/ Set the OFFSET to 01.999.9. 4/ Tune the RIG to the Highest Band Edge of 145.999.9 MHz 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ Button. You should now have 146.999.9 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 again. You should now have 147.999.9 MHz on your Digital Readout. 8/ Increase the OFFSET to 03.999.9. 9/ Repeat Steps 5 & 6 Twice more, Alternating between both until you get 149.999.9 MHz, On you Digital Readout. 10/ Increase the OFFSET to 05.999.9. 11/ Repeat Steps 5 & 6 Twice more, Alternating between both until you get 151.999.9 MHz, On your Digital Readout. Keep on Increasing the OFFSET by 2 until you get the OFFSET up to 99.999.9, And at the same time keep on Repeating Steps 5 & 6 Twice after every Increase in the OFFSET, until you get the Frequency up to 245.999.9 MHz PAGE 1 MOD 2 For the American Version Only. some of these moves are the same. but you can do the European Version on an American RIG. Though you can not do the American Version on an European RIG. Instructions Make sure that you put the Highest Frequency into VFO B, and the Lowest Frequency into VFO A. 1/ Turn on your RIG. 2/ Put the Rig into Repeater shift for the 144 MHz Band, By pressing the - RPT KEY ( KEY 5 ). 3/ Set the OFFSET to 03.999.9. 4/ Tune the RIG to the Highest Band edge, of 147.999.9 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ Button. You Should now see 148.999.9 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 Three times more, Alternating between both until you see 151.999.9 MHz on your Digital Readout. 8/ Increase the OFFSET to 07.999.9. 9/ Repeat Steps 5 & 6 Four time more, Alternating between both until you see 155.999.9 MHz on your Digital Readout. 10/ Increase the OFFSET to 11.999.9. 11/ Repeat Steps 5 & 6 Four Times more, Alternating between both until you see 159.999.9 MHz on your Digital Readout. Keep on Increasing the OFFSET by 4, until you get the OFFSET to 99.999.9. And at the same time Keep on Repeating Steps 5 & 6 Four times more after every Increase in the OFFSET until you get the Frequency to 245.999.9 MHz. STAGE 2 Now that you have 245.999.9 MHz in VFO B, And 144.000.0 MHz in VFO A, We come to the next move, Which is this, Press the Function key which is marked with an (F), Followed by the PMS KEY ( KEY 3 ), This stores the New Band edges in the PMS, Now Press the PMS key again, This time Tune to the Highest Frequency in the PMS, Which should now be 245.999.9 MHz. Make sure you have 245.999.9 MHz in VFO B, Make sure that the Frequency in VFO A is Lower than the Frequency in VFO B. Make sure that the Repeater shift is set to - RPT. Make sure that the OFFSET is set to 99.999.9. 1/ Press the REV KEY ( KEY 5 ). 2/ Press the DOWN MHz Button. PAGE 2 3/ Now Repeat Steps 1 & 2 Alternating between both until you get the Frequency to 345.999.9 MHz in the PMS. 4/ Now Press the Following Keys( Key 9,Key 2,Key 4,Key 9 again) in that order. The Magic Number is 9,2,4,9. 5/ Press the F KEY followed by the PMS KEY. This stores the New band edges back in the PMS. 6/ Press the PMS KEY again, Now Tune to the Highest Frequency in the PMS, Which should be 345.999.9 MHz. 7/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency up to 445.999.9 MHz. 8/ Repeat the Magic Number of 9,2,4,9. 9/ repeat Step 5. 10/ Repeat Step 6. And Tune to the Highest Frequency in the PMS, Which should be 445.999.9 MHz. 11/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency to 545.999.9 MHz. 12/ Repeat the Magic Number of 9,2,4,9 in that order. 13/ Repeat Step 5. 14/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 545.999.9 MHz. 15/ Repeat Steps 1 and 2 Alternating between both until you get the Frequency up to 645.999.9 MHz. 16/ Repeat the Magic Number 9,2,4,9. 17/ Repeat Step 5. 18/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 645.999.9 MHz. 19/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 745.999.9 MHz. 20/ Repeat the Magic number of 9,2,4,9. 21/ Repeat Step 5. 22/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 745.999.9 MHz. 23/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency up to 845.999.9 MHz. 24/ Repeat the Magic Number of 9,2,4,9 in that order 25/ Repeat Step 5. 26/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 845.999.9 MHz. 27/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 945.999.9 MHz. 28/ Repeat the Magic Number of 9,2,4,9 in that order. 29/ Repeat Step 5. 30/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 945.999.9 MHz. 31/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 999.999.9 MHz, Be careful not to go Passed 999.999.9 MHz, Because the Rig automatically Default back to 945.999.9 MHz, And you will have to start again from that point. PAGE 3 32/ Repeat the Magic Number of 9,2,4,9. 33/ Repeat Step 5. 34/ Repeat Step 6, Now slowly Tune Across the Two Band Edges, Until you see 00.000.0 MHz, 35/ Now Whilst still in the PMS Press the VFO A Button. 36/ Repeat the Magic Number of 9,2,4,9. 37/ Repeat Step 5. 38/ Repeat Step 6, Now Press either of the UP or DOWN scan Buttons, and you will find that the RIG will scan between 00.000.0 MHz to 999.999.9 MHz, or 999.999.9 MHz to 00.000.0 MHz. Now that you have set your RIG scanning UP and DOWN, you will find a number of signals on the Band, However you will hear signals up and down the Band that are not there, This can be checked out with a scanner, A signal Generator and a Digital Frequency Meter, But if you do not have these, Do not worry Because you do not need them, Simply put 138.000.0 MHz in to VFO A, And 156,999,9 MHz in to VFO B. 39/ Repeat the Magic Number of 9,2,4,9 in that Order. 40/ Repeat Step 5. 41/ Repeat Step 6. You Have completed this Modification, There are 3 more Mods for this Rig, with the Possiblity of a fourth for the American 220 MHz Band, But as yet I do not have any infomation on this Modification, Mod 2 is for 430/440 MHz, The OFFSET is 09.999.9. The Repeater Shift is + RPT. Press the REV KEY ( KEY 5 ) Followed by the UP MHZ BUTTON. Mod 3 is for 50 MHz, The OFFSET is 01.999.9. The Repeater Shift is + RPT. Press the REV KEY ( KEY 5 ) Followed by the UP MHZ BUTTON. Mod 4 IS for 1296 MHz, The OFFSET is 59.999.9. The Repeater Shift is + RPT. Press the REV KEY ( KEY 5 ) Followed by the UP MHZ BUTTON. Mod 5 is for 220 MHz, The OFFSET is 05.999.9. The Repeater Shift is + RPT. Press the REV KEY ( KEY 5 ) Followed by the UP MHz Button All These Mods are for Receiving only, and can not be used to Transmit out of Band. The End PAGE 4 Msg Nr. : 1557 Da : G0HEG Per : ALL @WW Tipo/status : BF Data/ora : 0219/2252 Dimensione : 9004 Titolo : MODS FOR FT736R MOD 2 Bid (Mid) : 50638_GB7WRG MODIFICATION OF THE PMS ON THE FT736R FOR 430 MHZ MOD 2 BY G0HEG Modification of the PMS on the FT736R for the 430 MHz Band, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receivea be extended from about 425 MHz to around 459 MHz. by the use of the Repeater shift, This gives a coverage of about 34 MHz, There is no need to snip any of the components, And you will not need a soldering Iron for this Modification. Instructions Make sure that when you start this Mod that you are in VFO A. Make sure that you put the Highest Frequency in to VFO B, and the Lowest one in to VFO A. Be careful not to Touch the UP or Down Scan Buttons on your RIG Whilst doing these Mods. Be careful not to Touch the Main Tuning knob on your RIG Whilst doing these Mods Please Note Also, Do not Press any scan Buttons on you FT736R, Do not Press the Channel Buttons or the Tuning Knob, Because if you Do Turn the Channel Knob the wrong way, you will lose all that you have done so far, What happens is this ( Press the wrong way the RIG will default back to 430 MHz. Turned the wrong way it will Default Back to 430 MHz Only Press or Turn Those Knobs Buttons or keys specified in these Mods. 1/ Turn on your RIG. 2/ Put the RIG into Repeater Shift for the 430 MHz Band, By pressing the + RPT KEY. 3/ Set the OFFSET to 09.999.9. 4/ Tune the RIG to the Lowest Band edge of 430.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. 7/ Repeat Steps 5 & 6 Nine Times more, Alternating Between Both until you get the Frequency down to 420.000.0 MHz. 8/ Increase the OFFSET to 19.999.9. 9/ Repeat Steps 5 & 6 Ten Times, Alternating Between both until you get the Frequency down to 410.000.0 MHz. 10/ Increase the OFFSET to 29.999.9. 11/ Repeat Steps 5 & 6 Ten Times, until you get down to 400.000.0 MHz. 12/ Increase the OFFSET to 39.999.9. 13/ Repeat Steps 5 & 6 Ten Times, until you get down to 390.000.0 MHz. 14/ Keep on Increasing the OFFSET by Ten, and after every Increase in the OFFSET, Repeat Steps 5 & 6 Ten Times, Until you get the OFFSET to 99.999.9, And the Digital Read out to 330.000.0 MHz. PAGE 1 STAGE 2 Now that you have got so far it is Important that you follow the next few moves to the letter. 1/ Press the Function Key Which is Marked with an ( F ) 2/ Press the PMS KEY ( KEY 3 ). You have just stored your New Band Edges in to the PMS, to check this out simply Press the PMS KEY, and Press either of the up or down Scan Buttons, you will find that the RIG will scan up or down either way, tthat Depends on which Button was Pressed first. Now that you have 330.000.0 MHz in the PMS, Make sure that you have an OFFSE of 99.999.9. in the PMS, also Make surtat the Repeater Shift is in the + RPT position. 3/ Tune to the Lowest Frequency in the PMS which should Now be 330.000.0 MHz. 4/ Press the REV KEY ( KEY 5 ). 5/ Press the UP MHz Button. 6/ Repeat Steps 5 & 6 Alternating Between both until you get your Digital Readout Down to 230.000.0 MHz 7 Pres the Magic Nmber f 9,2,4,9 in that order. 8/ Press th FKey folowd by the PMS ke. 9/ Press the PMS Key again, Now tune to the lowest Frequency in the PMS Which should now be 230.000.0 MHz. 10/ Repeat Steps 5 & 6 Alternating Between both until you get the Frequency Down to 130.000.0 MHz 11/ Press the i Number of 9,2,4,9 in that order. 12/ Press the F Key followed by the PMS Key. 13/ Press the PMS KEY again, And Tune to the Lowest Frequency in the PMS, 14/ Repeat Steps 5 & 6 Alternating until you get the Frequency down to 30.000.0 MHz. 15/ Press the Magic Number of 9,2,4,9, in that order. 16/ Press the F KEY followed by the PMS Key. 17/ Press the PMS Key, Now Tune the lowest Frequency ih PMS which should now be 30.000.0 MH 18/ Repeat Steps 5 & 6 Alternating Between both until you get the Frequency down to 00.000.0 MHz, Be careful not to go Passed this Frequency, Because the RIG will automatically Default Back to 30.000.0 MHz, And you will have to start again from that point. 19/ Press the Magic Number of 9,2,4,9, in that order. 20/ Press the F Key followed by the PMS Key. PAGE 2 21/ Press the PMS Key again, This time Tune slowly across The Two Band edges, until you see 999.999.9 MHz on your Digital Readout. 22/ Whilst still in the PMS Press VFO B 23/ Press the Magic Number of 9,2,4,9 in that order. You should Now Have 00.000.0 MHz in VFO A, And 999.999.9 MHz in VFO B. 24/ Press the F Key Followed by the PMS Key. 25/ Press the PMS Key again. THE END PAGE 3 Msg Nr. : 1550 Da : G0HEG Per : ALL @WW Tipo/status : BF Data/ora : 0219/2246 Dimensione : 8191 Titolo : MODFOR FT736R MOD 3 Bid (Mid) : 50640_GB7WRG MODIFICATION OF THE PMS ON THE FT736R FOR HE550 MHZ BAND MOD 3 BY G0HEG AND G0TVL I have not done this Modification, At the Time of writing I can not do this Modification, Because I do not have the 50 MHz Board in my FT736R, But I know of a Friend of mine who after a chat with me on 2 Mtrs, did this Modification on his RIG, It is one of the easiest of the Modifications for the FT736R. Modification of the PMS on the FT736R for the 50 MHz Band Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 46 MHz to around 56 MHz, By the use of the Repeater Shift, This give a coverage of about 10 MHz, But it may be Greater or Smaller than this, There is no need to snip any of the components, and you will not need a soldering Iron for this Modification. Instruction Make sure that you Put the Highest Frequency in to VFO B, and the Lowest one in to VFO A. 1/ Turn on your RIG. 2/ Put the RIG into Repeater Shift for the 50 MHz Band, By Pressing the + RPT KEY. 3/ Set the OFFSET to 01.999.9. 4/ Tune the RIG to the Lowest Band edge, of 50.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. You should now see 49.000.0 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 Once More, Alternating between both until you see 48.000.0 MHz on your Digital Readout, 8/ Increase the OFFSET to 03.999.9. 9/ Repeat Steps 5 & 6 Twice, This takes the Frequency to 46.000.0 MHz. 10/ Increase the OFFSET to 05.999.9. 11/ Repeat Steps 5 & 6 Twice, This takes the Frequency to 44.000.0 MHz. 12/ Keep on Increasing the OFFSET by 2, until you get the OFFSET to 51.999.9. 13/ at the same time as you Increase the OFFSET by 2, Repeat Steps 5 & 6 Twice after every Increase in the OFFSET, until you get 00.000.0 MHz on your Digital Readout. Be careful not to go beyond 00.000.0 MHz, Because the RIG will Automatically Default back to 50 MHz and you will have to start again, It is so frustrating when you lose so much of what you have already done. PAGE 1 STAGE 2 Now you should have been using VFO A as the starting point, you should have 53.999.9 MHz in VFO B, and 00.000.0 MHz in VFO A. Press the Function KEY which is Marked with an ( F ), Followed by the PMS KEY ( KEY 5 ), You have Just stored your New Band Edges in to the PMS. Press the PMS KEY again, this time slowly Tune across the Two Band Edges, Until you see 999.999.9 MHz appear on your Digital Readout, Now whilst still in the PMS, Press the VFO B Button. These Next Few Steps Are Very Important 1/ Press The following KEYS ( KEY 9,KEY 2,KEY 4,KEY 9 in that order). The Magic Number is 9,2,4,9. 2/ Now Press the F KEY, followed by the PMS KEY. 3/ Press the PMS KEY again. You have Just stored the New Band Edges in to the PMS, you Should now have in VFO A, Which should be 00.000.0 MHz, and in VFO B, you should also have 999.999.9 MHz Press either of the UP of DOWN scan Buttons. You will now find that your FT736R will now scan up and down the Band from 00.000.0 MHz to 999.999.9 MHz, or from 999.999.9 MHz to 00.000.0 MHz. There are 3 other Mods for the FT736R, that you can do if your RIG as the Boards in it, Also there may be another Mod for the American 220 MHz Band but at the time of writing I do not know if it can be done. List of Mods for the FT736R as found by G0HEG and G7OHY. Mod 1/ is for the 144 to 148 MHz band, - RPT Plus Down MHz Button, Frequency 139 to 155 MHz. Mod 2/ for the 430 to 450 MHz Band, + RPT Plus Up MHz Button, Frequency 425 to 459 MHz. Mod 3/ is for the 50 MHz Band, + RPT Plus Up MHZ Button. Frequency 45 to 56 MHz ?. Mod 4/ is for the 1296 MHz Band, + RPT Plus Up MHz Button, Frequency 1215 to 1326 MHz ?. Mod 5/ is for the Americn 220 MHz Band, RT Plus UP or DOWN MHz Button, Freuqency 216.6 to 230 MHz ?. All these Mods are for Receiving only and can not be used to transmit on. PAGE 2 Msg Nr. : 1133 Da : G0HEG Per : ALL @WW Tipo/status : BF Data/ora : 0219/0501 Dimensione : 7103 Titolo : MODS FOR FT736R MOD 4 Bid (Mid) : 50644_GB7WRG MODIFICATION OF THE PMS ON THE FT736R FOR THE 1296 MHZ BAND. MOD 4 BY G0HEG Modification of the PMS on the FT736R for 1296 MHz, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 1215 MHz toabou 1326Mz, by the useof the Repeater shift his givs a coverae of about111 MHz. Ther is no need to snip any o the compoents, and you will not need a soldering Iron for this modification. INSTRUCTIONS Make sure that you put the Highest Freqncy into VFO B, Make s hat you put the Lowest Frequency into VFO A. 1/ Turn on your RIG. 2/ Put the RIG into Repeater shift for the 1296 MHz band, By pressing the + RPT KEY. 3/ Set the OFFSET t59.999.9. 4/ Tune the RIG to the Lowest band edge, of 1240.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press P MHz BUTTON. 7/ Repeat steps 5 & 6 Alternating between both until you get the Frequency down to 1180.000.0 MHz. 8/ Increase the OFFSET to 99.999.9. 9/ Repeat steps 5 & 6 Alternating between both until you get the Frequency down to 1140.000.0 MHz. STAGE 2 You should now have 1299.999.9 MHz in VFO B, And 1140.000.0 MHz in VFO A. Make sure that the OFFSET in the PMS is set at 99.999.9. Make sure that you have the Repeater Shift set in the + RPT position. 1/ Press the F key followed,by the PMS KEY ( KEY 3 ). You have just stored the New band edges in your PMS. 2/ Press the PMS KEY again, now Tune to the Lowest Frequency in the PMS. Which should now be 1040.000.0 MHz. 3/ Press REV KEY ( KEY 5 ). 4/ Press the UP MHz BUTTON. 5/ Keep Alternating between steps 3 & 4 until you get the frequency down to 1040.000.0 MHz. 6/ Now Press the following KEYs( KEY 9,KEY 2,KEY 4,KEY 9 ). The Magic Number is 9,2,4,9. You should now have 1040.000.0 MHz in VFO A. 7/ Repeat Step 1. PAGE 1 8/ Repeat step 2, and Tune to the lowest Frequency in the PMS. 9/ Repeat step 3. 10/ Repeat step 4. 11/ Keep Alternating between steps 3 & 4 until you get the Frequency down to 1000.000.0 MHz, becareful not to go over 1000.000.0 MHz, because the RIG will Automatically Default back to 1040.000.0 MHZ, and you will have to start again from that point. 12/ Repeat step 6. 15/ Repeat step 1, By Pressing the Function KEY, Followed by the PMS KEY ( KEY 3 ). 16/ Repeat step 2, Press the PMS KEY and Tune across the Two band edges, until you see 1999.999.9 MHz on your Digital Readout, 17/ Now whilst still in the PMS press the VFO B Button. 18/ Press the Magic Number of 9,2,4,9. 19/ Repeat step 1. 20/ Press the PMS KEY, But this time Press either of the UP or DOWN scan buttons, Your RIG will now scan between 1000.000.0 MHz and 1999.999.9 MHz or 1999.999.9 MHz to 1000.000.0 MHz. As stated at the begining of this Modification the RIG will Receive from about 1215.000.0 MHz to around 1326.000.0 MHz. This Modification is for Receiving only, you can not use it to transmit outside your allowcated Frequency. the End of Mod 4 There are 3 more Mods for the FT736R, One for every Band that it will Receive on. HERE IS THE LIST MOD 1. 144 TO 148 MHz - RPT plus Down MHz Button, the OFFSET is 01.999.9. MOD 2 430 TO 458 MHZ + RPT plus Up MHz Button, the OFFSET is 09.999.9. MOD 3. 46 TO 56 MHz + RPT plus Up MHz Button, the OFFSET is 01.999.9. MOD 4 1215 to 1326 MHz + RPT plus Up MHz Button, the OFFSET is 59.999.9. MOD 5 216.6 to 230 MHz + RPT plus Up MHz Button, the OFFSET is 04.999.9. THE END PAGE 2 Msg Nr. : 1546 Da : G0HEG Per : ALL @WW Tipo/status : BF Data/ora : 0219/2237 Dimensione : 7802 Titolo : MODS FOR FT736R MOD 5 Bid (Mid) : 50647_GB7WRG MODIFICATION OF THE PMS ON THE FT736R FOR THE 220 MHZ BAND MOD 5 BY G0HEG Modification of the PMS on the FT736R for 220 MHz, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 216.6 MHz to around 230 MHz By the use of the repeater shift, This gives a coverage of about 13.4 MHz. There is no need to snip any of the components, And you will not need a soldering Iron for this Modification. Important notice Make sure that you put the Highest Frequency into VFO B, Make sure that you Put the lowest Frequency into VFO A. When you start this Mod make sure that you are in VFO A, Because this will save you a lot of work later on. Instruction 1/ Turn on your Rig. 2/ Put the RIG into Repeater shift for 220 MHz Band, by pressing the + RPT KEY. 3/ Set the OFFSET to 04.999 4/ Tune the RIG to the lowest Band edge of 220.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. You should now have 219.000.0 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 again Four Times More, Alternating between both Until you get 214.000.0 MHz on your Digital Readout. 8/ Increase the OFFSET to 09.999 9/ Repeat Steps 5 & 6 five Times More, Alternating etween both until you get 209.000.0 MHz on your Digital Readout. 10/ Increase the OFFSET to 13.999.9 11/ Repeat Steps 5 & 6 five Times More. 12/ Keep on Increasing the OFFSET by FIVE until you get the OFFSET up to 99.999.9. 13/ Keep on Repeating Steps 5 & 6 FIVE Times after every increase in the OFFSET until you Get the Frequency to 120.000.0 MHz. Now that you have 120.000.0 MHz in VFO A, you should also have 224.999.9 MHz in VFO B. PAGE 1 STAGE 2 1/ Press the F KEY followed by the PMS KEY ( KEY 3 ). 2/ Press the PMS KEY again, You have Just stored the New Band Edges in to your PMS, Now press either of the UP or DOWN scan Buttons on your IG, and you will see your RIG scanning Between 120.000 0 MHz and 224.999.9 MHz, 224.999.9 MHz to 120.000.0 MHz, But that Depends on which Button you Pressed first. Make sure hat your IG i in the + RPT oition. 3/ Now Tne t te Lowes Fequency in your PMS, Which should e 20.00.0 MHz. 4/Set the OFSET to 9.999.9. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ BUTTON. 7/ RepatSteps 5 & 6 Alternating Between both until you Get the Frequency Down to 20.000.0 MHz. 8/ Now Press the following Keys ( Key 9,Key 2,Key 4,Key 9 Again. The Magic Number is 9,2,4,9. You should now have 20.000.0 MHz in VFO A, And 224.999.9 MHz in VFO B. 11/ Repeat Step 1. 12/ Repeat Step 2. 13/ Now Tune to the Lowest Frequency in your PMS Which should be 20.000.0 MHz 14/ Repeat Steps 5 & 6 Alternating between both until you get the Frequency in the PMS to 00.000.0 MHz care should be taken not to go passed 00.000.0 MHz because the RIG will automatically Default back to 20.000.0 MHz and you will have to start again from That point. 15/ Now Press the Following KEYS (9,2,4,9 in that order). The Magic Number is 9,2,4,9. 16/ Repeat Step 1. 17/ Repeat Step 2. Now that you are in the PMS you should have 00.000.0 MHz in VFO A and 224.999.9 MHz, Whilst still in the PMS Tune across the Two Band Edges From 249.999.9 MHZ to 00.000.0 MHz until you see 999.999.9 MHz, on your Digital Readout. Now Whilst still in the PMS press the VFO B Button. 18/ Now Press the Following Keys( Key,24,9 in that Order ). 19/ Repeat Step 1. 20/ Repeat Step 2. You ud now have 00.000.0 MHz in VFO A, and 999.999.9 MHz in VFO B. Now press either of the up or down scan Buttons, and you will find that your RIG will scan up or down depending on the Buttyu Pressed First. You will have to set your own Band edges on this Mod Because I am not allowed to have this board in My RIG, as far as I am aware KU2A is the only one who as done this MOD He told me that the Band edges were 216.6 MHz to 230 MHz His comments were "It Works Well " De G0HEG PAGE 2 Msg Nr. : 32817 Da : IW3GRX Per : IW3GRX Tipo/status : PN Data/ora : 0417/2116 Dimensione :24591 Titolo : Alcune modifiche per l'FT736 Bid (Mid) : 32817_IW3GRX ============================================================================= ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ The FT-736R SAT switch can zap pre-amps. The 736R SAT switch has break-before-make contacts, which meanhat in between switch positions the circuit is the same as if the SAT switch is in the OFF po sition. If you have set up one of the modules to transmit for non-satellite op erations (i.e., w hen SAT switch is OFF), that module will be enabled between the RX-TX-NOR-REV p ositions of the SAT switch.f you are transmitting while you move the SAT swi tch between these positions you may accidently key up the unintended module and send a burst of RF down the antenna line into your pre-amp. For example: VFO A happens to be set to operate on 2 meter FM. You don't give this a second thought, since you are working Mode B CW with the SAT switch ON. You are listening on 2 meters and keying your 70 CM transmitter trying tor o your downlink f requency. Changing the SAT switch positions under these conditions is perfectl y normal. However, if you happen to send a dot or dash during the open interval been s witch positions it is not your 70 CM transmitter that gets keyed but your 2 met er FM transmitter. This sends a burst of RF down the 2 meter coax that you hav e configured for receiving. If you have in that coax a preamp without adequate RF-sensed pin-di ode switching, then say goodbye to the GaAsFETs in the preamp. If you are using the FT-736R preamp switch and the 12 VDC on the coax to operat e coax relays at the preamp, you might be lucky -- if the relays drop out fast enough. I don't know if the control circuits operate fast enough to take car e of this transie nt condition, but I doubt it. This cost me two MGF-1402 GaAsFETs in my unprotected homebrew 2 meter preamp be fore I realized that they both departed this world under exactly the same circu mstances of operation of the SAT switch while sending. Although I was on CW, t he same thing cou ld happen on SSB if you happened to be speaking and the VOX were to be operated during the switch rotation. Thanks to John, KL7GRF, for clueing me to the real problemhe SAT switch while t ransmitting. (2) Use adequate RF sensed mp switching. ============================================================================= From: DD9ZO @ DB0SIF.DEU.EU To : YAESU @ WW A small modification to get a better audio-signal out of the TX from FT736R. ---------------------------------------------------------------------------- (deutscher Text siehe weiter unten.) Hello FT 736 Fans, The FT736R tranceiver is a well done rig, but the TX-signal is not very readable by the QSO-partner if the signal-stregth ist low. The FT736 prefer the low frequencies in the audio-signal an cut off all high frequencies in the speech-signal. In FM-Mode it sounds like a bass-man..hi . In SSB-mode the Power-Amplifier is working hard an only the lower speech-band is transmitted. There are a few little modifikation to reduce this problem: 1.) change the mikrophone in the handheld-case to a better one. (try several mikrofones at a resistance abuot 600 Ohms) 2.) open the FT736 (upper case) and locate the TX-Board (on the left upper left side if the front is showing to You). On this TX-UNIT cut the Capacitor C 14 (Value 0.001uf) . The Capacitor is located in the right-bottem corner of the board. Adjust for FM-Mode the Potentiometer VR 01 just a little tick clockwise ( deviation-limiter). If You can use a deviation-meter You can do this in a professional way. (about +- 5 Khz). 3.) If You are using a preamp-mikrophone, make sure to adjust the level from this mike so that the mike-gain-potentiometer at the frontpanel from the FT736 are minimum in the 11 o`clock position for a good drive of the powerstage. Otherwise You will overdrive the first mikeamplifier in the rig. This sounds like speaking in a train-station... When You are using a preamp-mike connect a small 600 Ohm resistor direct in the mike-plug between point 8 (middelplug) and point 7 (GND) So the rig always have the correct 600 Ohms resistance. 4.) Best results I got whit a mike, that produceses a strong signal in the higher audio-band (about 2000 Hz). By the way, the PROC-Switch only works at SSB and only when You get down with the drive-gain... if the ALC-Meter is on the right scale, the PROC- switch has no affect ! ALLWAYS think of loosing warrenty if You modify something inside the FT736 !! Vy.73 de Guenter DD9ZO in Mailbox DB0SIF Germany. ----------------------------------------------------------------------------- Deutscher Text hier: Kleine Modifikationen fuer ein besseres Audio-Signal beim Senden vom FT736R. Hallo FT736 Fans, Der FT736 ist ein prima Geraet, aber das Sendesignal ist von der Sprach- qualitaet miserabel. Die Sprache klingt hohl und besonders in FM viel zu tief. Bei SSB-Berieb schafft die Endstufe wie doll aber es werden nur die tiefen Toene der Sprache uebertragen. Der QSO-Partner versteht bei schwachem Signal meistens nicht sehr viel. Hier nun einige kleine Aenderungen um dieses Problem zu mindern: 1.) werft die Mikrkabsel aus dem Handmikro in den Muell. Versucht es mit anderen 600 Ohm-Kapseln. 2.) oeffnet den oberen Deckel des FT736 und sucht die TX-Baugruppe. Die TX-UNIT ist auf der linken Oberseite wenn die Frontplatte zu Euch zeigt. Entfernt den Kondensator C 14 am Mikeeingang hinter den 1 KOhm Widerstand. Dieser Kondensator liegt in der unteren rechten Ecke auf der Platine. Ich habe die Baugruppe deshalb nicht ausgebaut, habe die "russische Methode" also Durchkneifen angewendet... Der C hat den Wert 0,001uF. Fuer den FM-Betrieb dreht den Poti VR 01 einen kleinen Tick weiter in Richtung Uhrzeigersinn (Hub-Begrenzung) Mit einem Hubmesser kann man das auch professionell einstellen... 3.) Wenn Ihr ein Vorverstaerker-Mike benutzt, stellt den Pegel dieses Mikes so ein, dass Ihr den Mike-Gain auf der Frontplatte auf Mnimum 11 Uhr Position stehen habt und dann ein normales Signal sendet. Wenn Ihr den Pegel des Mikrofons zu hoch einstellt wird der erste Mike-versterker im FT736 uebersteuert, das erzeugt die Gieskannen-Modulation. Ebenfalls sollte bei Benutzung eines VV-Mike im Mikestecker der Pin 8 (Mittelpin) und der Pin 7 (GND) mit einem 600 Ohm-Widerstand gebrueckt werden. Der FT736 sieht dann immer die richtige Impedance. 4.) Beste Resul”tate habe ich mit einem Mike erhalten, das den oberen Sprachbereich bevorzugt (ueber 2000 Hz). Ach ja, moch was, der PROC-Schalter wirkt nur bei SSB und NUR wenn Ihr gleichzeitig den DRIVE-Regler zurueckstellt. Wenn das ALC-Meter schon am rechten Poller klebt, nuetzt der Proc-Schalter nichts mehr !!! WICHTIG: Denkt an den Garantieverlust bei Aenderungen im Geraet !!! Vy. 73 de Guenter DD9ZO in DB0SIF ============================================================================== ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ I bought a Yaesu FT736 about 6 months ago. It's a great radio but one thing annoyed me about it. When I used in on FO-20 or the microsats with my TAPR PSK modem, the PSK modem adjusts to the doppler frequency shift by sending pulses to the up/down buttons on the microphone. Only problem is, everytime it sent a pulse the radio went BEEP. This beep didn't come thru the speaker, instead it was emitted from a separate buzzer. As a result, even when using the headphomes, the beep would disturb the whole house. This was a particular problem on late night passes. Thanks to a suggestion from WB2IBO and the folks at Yaesu, I've discovered you can fix the problem. If you remove the top cover you will find a circuit board right behind the front panel. As you are facing the front of the radio on the top left corner you will see capacitor C63 identified on the board with a red wire going into the circuit board next to it. Clip the red wire and no more beep. You won't actually see the beeper. To find the beeper you have to remove the top and bottom covers (see the manual) and then loosen the screws on either side of the front panel (see section 3.5.4 in the manual). At the bottom left of the circuit board is the black buzzer, about the size of a quarter. The red wire you need to clip starts from here. You don't actually have to remove the bottom cover if you clip it where it goes back into the circuit board on the top, however. You could rig up a switch to turn the buzzer off and on, but I don't why anyone would ever want to turn it back on. 73 de WA0PTV @WA0PTV Here are some routines to drive a Yaesu FT736R CAT interface. Note that the radio has TTL levels, so you need to build a circuit to convert RS232 voltages to TTL voltages. You can do this with a MAX231 etc, or a couple of NPN transistors. The latter can be mounted inside your DB25 connector. ============================================================================== ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ I bought a Yaesu FT736 about 6 months ago. It's a great radio but one thing annoyed me about it. When I used in on FO-20 or the microsats with my TAPR PSK modem, the PSK modem adjusts to the doppler frequency shift by sending pulses to the up/down buttons on the microphone. Only problem is, everytime it sent a pulse the radio went BEEP. This beep didn't come thru the speaker, instead it was emitted from a separate buzzer. As a result, even when using the headphomes, the beep would disturb the whole house. This was a particular problem on late night passes. Thanks to a suggestion from WB2IBO and the folks at Yaesu, I've discovered you can fix the problem. If you remove the top cover you will find a circuit board right behind the front panel. As you are facing the front of the radio on the top left corner you will see capacitor C63 identified on the board with a red wire going into the circuit board next to it. Clip the red wire and no more beep. You won't actually see the beeper. To find the beeper you have to remove the top and bottom covers (see the manual) and then loosen the screws on either side of the front panel (see section 3.5.4 in the manual). At the bottom left of the circuit board is the black buzzer, about the size of a quarter. The red wire you need to clip starts from here. You don't actually have to remove the bottom cover if you clip it where it goes back into the circuit board on the top, however. You could rig up a switch to turn the buzzer off and on, but I don't why anyone would ever want to turn it back on. 73 de WA0PTV @WA0PTV Here are some routines to drive a Yaesu FT736R CAT interface. Note that the radio has TTL levels, so you need to build a circuit to convert RS232 voltages to TTL voltages. You can do this with a MAX231 etc, or a couple of NPN transistors. The latter can be mounted inside your DB25 connector. 1. The Yaesu spec contains one or two typos which are herein connected. 2. It does not appear to be necessary to space out the 5 control bytes by 50 ms. 3. The READ S-meter, squelch functions smetimes fail to return all 5 bytes, so the code (FNget) accomodates this. REM REM FT736R CAT Interface Drivers REM ---------------------------- REM Last modified 1990 May 21 REM REM (C)1990 J R Miller G3RUH REM REM Procedures and functions available are: REM REM PROCcat(on|off) REM PROCmode(lsb|usb|cw|cwn|fm|fmn) REM PROCptt(on|off) REM PROCsplit(off|plus|minus) REM PROCoffset(MHz) REM PROCfreq(MHz) (* e.g. MHz = 145.6789 etc *) REM PROCfull_dup(on|off) REM PROCsat_mode(tx|rx , lsb|usb|cw|cwn|fm|fmn) REM PROCsat_freq(tx|rx , MHz) REM FNsqlch (* returns 0 if no signal *) REM FNmeter (* returns S-meter value *) REM REM REM Example - prepare FT736R for FUJI-OSCAR-20 satellite REM ==================================================== PROCset_up: REM Do once only per session! PROCcat(on) PROCfull_dup(on) PROCsat_mode(rx,usb): PROCsat_freq(rx,435.916) PROCsat_mode(tx,fm ): PROCsat_freq(tx,145.850) PROCcat(off) END : REM Now follows procedures and functions : DEF PROCcat(F%) IF F%=on B%(5)=0 ELSE B%(5)=&80 PROCput: ENDPROC : DEF PROCmode(B%(1)) B%(5)=7: PROCput: ENDPROC : DEF PROCptt(F%) IF F%=on B%(5)=8 ELSE B%(5)=&88 PROCput: ENDPROC : DEF PROCsplit(F%) B%(5)=&89: REM simplex IF F%=plus B%(5)=&49 IF F%=minus B%(5)=9 PROCput: ENDPROC : DEF PROCoffset(F) B%(5)=&F9 PROCfr(F) PROCput: ENDPROC : DEF PROCfull_dup(F%) IF F%=on B%(5)=&E ELSE B%(5)=&8E PROCput: ENDPROC : DEF PROCsat_mode(F%,B%(1)) IF F%=tx B%(5)=&27 ELSE B%(5)=&17 PROCput: ENDPROC : DEF PROCfreq(F) B%(5)=1 PROCfr(F) PROCput: ENDPROC : DEF PROCsat_freq(F%,F) IF F%=tx B%(5)=&2E ELSE B%(5)=&1E PROCfr(F) PROCput: ENDPROC : DEF PROCfr(F) IF F>=1000 FX%=on ELSE FX%=off F=(F+0.000005)/1000 FOR I%=1 TO 4: F=F*100: F%=INT(F): F=F-F% B%(I%)=(F% DIV 10)*16 + F% MOD 10 NEXT IF FX%=on B%(1)=B%(1)AND &F + &C0: REM 1200 MHz band corrrection ENDPROC : DEF FNsqlch B%(5)=&E7: PROCput: PROCget IF B%(1)=0 THEN =0 ELSE= -1 : DEF FNmeter B%(5)=&F7: PROCput: PROCget =B%(1) : DEF PROCset_up REM Establish constants etc DIM B%(5) off=0: on=-1 rx =0: tx=-1 plus=+1: minus=-1 lsb=0: usb=1: cw=2: cwn=&82: fm=8: fmn=&88 : REM Most code after this is for controlling the BBC micro hardware REM and needs recoding for any other machine. Note "*FXn,m" is REM merely a BBC micro operating system call, no. n, parameter m. REM REM Set up RS423 = 4800,8,N,2 *FX8,6 *FX7,6 *FX156,16,227 ENDPROC : DEF PROCput REM Procedure sends five bytes to RS432c port, spaced by 50ms REM bytes are in array B%(1) ... B%(5) FOR I%=1 TO 5 REM Delay below is in the spec, but can actually be omitted T%=TIME: REPEAT UNTIL TIME >= T%+5: REM Wait 50 ms/byte REM Now direct output to RS423, o/p char, and restore o/p to screen *FX3,3 VDU B%(I%) *FX3,0 NEXT ENDPROC : DEF PROCget REM Flush RS423 I/P buffer, then read bytes from input stream REM until op code is detected. Previous value is result. REM (straight reading 5 bytes found to be unreliable) *FX15,1 *FX2,1 REPEAT B%(1)=B%: B%=GET: UNTIL B%=B%(5) *FX2,0 ENDPROC : REM End of code REM de G3RUH @ GB7SPV 1990 May 29 ============================================================================== ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ FO-20 & the Yaesu FT736R --------------------------- by James Miller G3RUH If like me, one of the (many) features that attracted you to the FT736R was the special DATA SOCKET, then you were probably very pleased to read in the manual: "This 3-contact mini stereo jack allows direct connection to the FM receiver demodulator and FM transmitter modulator for digital equipment such as a packet radio TNC. No pre-emphasis or de-emphasis is added to the signals at this jack" (page 14). Don't believe a word of it! A cursory inspection of the circuit diagram shows that the TX side is simply merged with the microphone audio just after the Mic Gain control, and is then murdered by several subsequent filters. On the RX side the data audio output is similarly indirect. My initial day with FO-20 was disastrous. (Yours too?) So I looked at the FM signal on a calibrated monitor receiver when transmitting FO-20/Microsat "Manchester" uplink signals. The waveform was appallingly distorted. The problem is that the TX LF response cuts off at 800 Hz. But the data has substantial energy at 600 Hz and below. Indeed, when transmitting a 600 Hz square wave it was clear from the droop distortion that FO-20 or a Microsat would almost certainly not decode the uplink reliably. The cure is simple; modulate the FM varactor directly. Refer to the circuit diagram; inject your TXaudio at the junction of R32/C29 on the TX Unit. The signal level at this point should be 800 mV peak-peak, and will give +/- 3 kHz deviation. DO NOT EXCEED THIS LEVEL. Set Mic Gain to min. The implementation is simple too. 1. Disconnect FT736R from the mains electricity. (Safety). 2. Remove top cover only. 3. TX Unit is the module flat on the left (not the one tucked down the side vertically). 4. R32 is just to the left of the rectangular shielded enclosure. The resistor is "on end". Scrape the paint off the free leg. 5. Your TXaudio lead should be a fine screened cable; connect the inner to R32, and the outer braid to the adjacent enclosure. 6. Route the cable out though any convenient aperture in the case. [ TXAudio of 800 mV pk-pk can be obtained from the G3RUH PSK modem by adjusting the components C9= 1uf, R3=47k, R5=infinity (i.e. remove). C10 stays at 10nf (0.01uf).] Modulating the FM transmitter this way you get an LF response down to 18 Hz (at which point the associated synthesiser PLL begins to track the modulation), and an HF response which is flat to some 10 kHz. *** FO-20/Microsat uplink modulation is now absolutely perfect. *** G3RUH @ GB7SPV 1990 Feb 23 Amsat Tmail Address "UOSAT" ============================================================================== ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ The FT-736R SAT switch can zap pre-amps. The 736R SAT switch has break-before-make contacts, which meanhat in between switch positions the circuit is the same as if the SAT switch is in the OFF position. If you have set up one of the modules to transmit for non-satellite operations (i.e., when SAT switch is OFF), that module will be enabled between the RX-TX-NOR-REV positions of the SAT switch.f you are transmitting while you move the SAT switch between these positions you may accidently key up the unintended module and send a burst of RF down the antenna line into your pre-amp. For example: VFO A happens to be set to operate on 2 meter FM. You don't give this a second thought, since you are working Mode B CW with the SAT switch ON. You are listening on 2 meters and keying your 70 CM transmitter trying toro your downlink frequency. Changing the SAT switch positions under these conditions is perfectly normal. However, if you happen to send a dot or dash during the open interval been switch positions it is not your 70 CM transmitter that gets keyed but your 2 meter FM transmitter. This sends a burst of RF down the 2 meter coax that you have configured for receiving. If you have in that coax a preamp without adequate RF-sensed pin-diode switching, then say goodbye to the GaAsFETs in the preamp. If you are using the FT-736R preamp switch and the 12 VDC on the coax to operate coax relays at the preamp, you might be lucky -- if the relays drop out fast enough. I don't know if the control circuits operate fast enough to take care of this transient condition, but I doubt it. This cost me two MGF-1402 GaAsFETs in my unprotected homebrew 2 meter preamp before I realized that they both departed this world under exactly the same circumstances of operation of the SAT switch while sending. Although I was on CW, the same thing could happen on SSB if you happened to be speaking and the VOX were to be operated during the switch rotation. Thanks to John, for clueing me to the real problemhe SAT switch while transmitting. (2) Use adequate RF sensed amp switching. ============================================================================= ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ The FT-736R SAT switch can zap pre-amps. The 736R SAT switch has break-before-make contacts, which means that in between switch positions the circuit is the same as if the SAT switch is in the OFF posi tion. If you have set up one of the modules to transmit for non-satellite opera tions (i.e., when SAT switch is OFF), that module will be enabled between the RX -TX-NOR-REV positions of the SAT switch. If you are transmitting while you move the SAT switch between these positions you may accidently key up the unintended module and send a burst of RF down the antenna line into your pre-amp. For example: VFO A happens to be set to operate on 2 meter FM. You don't give this a second thought, since you are working Mode B CW with the SAT switch ON. You are listening on 2 meters and keying your 70 CM transmitter trying to zero your downlink frequency. Changing the SAT switch positions under these condi- tions is perfectly normal. However, if you happen to send a dot or dash during the open interval between switch positions it is not your 70 CM transmitter that gets keyed but your 2 meter FM transmitter. This sends a burst of RF down the 2 meter coax that you have configured for receiving. If you have in that coax a preamp without adequa te RF-sensed pin-diode switching, then say goodbye to the GaAsFETs in the preamp If you are using the FT-736R preamp switch and the 12 VDC on the coax to operate coax relays at the preamp, you might be lucky -- if the relays drop out fast enough. I don't know if the control circuits operate fast enough to take care of this transient condition, but I doubt it. This cost me two MGF-1402 GaAsFETs in my unprotected homebrew 2 meter preamp before I realized that they both departed this world under exactly the same cir- cumstances of operation of the SAT switch while sending. Although I was on CW, the same thing could happen on SSB if you happened to be speaking and the VOX were to be operated during the switch rotation. Thanks to John, KL7GRF, for clueing me to the real problemhe SAT switch while transmitting. (2) Use adequate RF sensed preamp switching. 73 de Dick, W2GFF @ N4SZO ============================================================================= ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ -==> PY4SM@PY4SM.BRA.SA <==- ÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜÜ FT 736R Extended Frequency coverage. I've received the modification information for the aforementioned radio. Remember, this is for CAP/MARS use only - Amateurs are NOT permitted to transmit outside of the Amateur bands without specific authorization. The mods take place on the 144 main unit (No. 6XXX). The diode array is in the lower left corner of the board, component side towards you, and the notches to the left. No information was given as to diode type, but I assume any small signal diode will work. D24 D25 D26 D27 X=Omit O=Installed ___________________ X O O X 144.0 - 148.0 (Standard US) ____________ X O O O 141.0 - 154.0 (Extended Rx/Tx) ____________ X X O O 144.0 - 146.0 (Non US) ____________ Jon Maguire N1CQE/4 =============================================================================== Msg Nr. : 66074 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2347 Dimensione : 3242 Bid (Mid) : 36835_GB7WRG Titolo : MODS FOR FT736R VHF 1 OF 4 MODIFICATION OF THE PMS ON THE FT736R FOR THE 144 TO 148 MHZ BAND MOD 1 BY G0HEG Modification of the PMS on the FT736R for VHF, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 139 MHz to around 155 MHz By the use of the Repeater shift, This gives a coverage of about 16 MHz, There is no need to snip any of the components, And you will not need a soldering Iron for this Modification, Instructions There are Two Mods for the FT736R for VHF, One is for the European Version, Which is the one that we will deal with first, And the other is for the American Version, That we will deal with later on. Important notice Make sure that you are in VFO B when you start this Mod Follow the instructions to the letter. Always put the Highest Frequency into VFO B, and the Lowest ones into VFO A. 1/ Turn on Your RIG. 2/ Put the RIG into Repeater shift for the 144 MHz Band, By Pressing the - RPT KEY. 3/ Set the OFFSET to 01.999.9. 4/ Tune the RIG to the Highest Band Edge of 145.999.9 MHz 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ Button. You should now have 146.999.9 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 again. You should now have 147.999.9 MHz on your Digital Readout. 8/ Increase the OFFSET to 03.999.9. 9/ Repeat Steps 5 & 6 Twice more, Alternating between both until you get 149.999.9 MHz, On you Digital Readout. 10/ Increase the OFFSET to 05.999.9. 11/ Repeat Steps 5 & 6 Twice more, Alternating between both until you get 151.999.9 MHz, On your Digital Readout. Keep on Increasing the OFFSET by 2 until you get the OFFSET up to 99.999.9, And at the same time keep on Repeating Steps 5 & 6 Twice after every Increase in the OFFSET, until you get the Frequency up to 245.999.9 MHz PAGE 1 Msg Nr. : 66086 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0718/0049 Dimensione : 3417 Bid (Mid) : 36838_GB7WRG Titolo : MODS FOR FT736R VHF 2 OF 4 MOD 2 For the American Version Only. some of these moves are the same. but you can do the European Version on an American RIG. Though you can not do the American Version on an European RIG. Instructions Make sure that you put the Highest Frequency into VFO B, and the Lowest Frequency into VFO A. 1/ Turn on your RIG. 2/ Put the Rig into Repeater shift for the 144 MHz Band, By pressing the - RPT KEY ( KEY 5 ). 3/ Set the OFFSET to 03.999.9. 4/ Tune the RIG to the Highest Band edge, of 147.999.9 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ Button. You Should now see 148.999.9 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 Three times more, Alternating between both until you see 151.999.9 MHz on your Digital Readout. 8/ Increase the OFFSET to 07.999.9. 9/ Repeat Steps 5 & 6 Four time more, Alternating between both until you see 155.999.9 MHz on your Digital Readout. 10/ Increase the OFFSET to 11.999.9. 11/ Repeat Steps 5 & 6 Four Times more, Alternating between both until you see 159.999.9 MHz Keep on Increasing the OFFSET by 4, until you get the OFFSET to 99.999.9. And at the same time Keep on Repeating Steps 5 & 6 Four times more after every Increase in the OFFSET until you get the Frequency to 245.999.9 MHz. STAGE 2 Now that you have 245.999.9 MHz in VFO B, And 144.000.0 MHz in VFO A, We come to the next move, Which is this, Press the Function key which is marked with an (F), Followed by the PMS KEY ( KEY 3 ), This stores the New Band edges in the PMS, Now Press the PMS key again, This time Tune to the Highest Frequency in the PMS, Which should now be 245.999.9 MHz. Make sure you have 245.999.9 MHz in VFO B, Make sure that the Frequency in VFO A is Lower than the Frequency in VFO B. Make sure that the Repeater shift is set to - RPT. Make sure that the OFFSET is set to 99.999.9. 1/ Press the REV KEY ( KEY 5 ). 2/ Press the DOWN MHz Button. PAGE 2 Msg Nr. : 66089 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0718/0103 Dimensione : 3657 Bid (Mid) : 36842_GB7WRG Titolo : MODS FOR FT736R VHF 3 OF 4 3/ Now Repeat Steps 1 & 2, Alternating Between both until you get the Frequency to 345.999.9 MHz in the PMS. 4/ Now Press the Following Keys( Key 9,Key 2,Key 4,Key 9 again) in that order. The Magic Number is 9,2,4,9. 5/ Press the F KEY followed by the PMS KEY. This stores the New band edges back in the PMS. 6/ Press the PMS KEY again, Now Tune to the Highest Frequency in the PMS, Which should be 345.999.9 MHz. 7/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency up to 445.999.9 MHz. 8/ Repeat the Magic Number of 9,2,4,9. 9/ repeat Step 5. 10/ Repeat Step 6. And Tune to the Highest Frequency in the PMS, Which should be 445.999.9 MHz. 11/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency to 545.999.9 MHz. 12/ Repeat the Magic Number of 9,2,4,9 in that order. 13/ Repeat Step 5. 14/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 545.999.9 MHz. 15/ Repeat Steps 1 and 2 Alternating between both until you get the Frequency up to 645.999.9 MHz. 16/ Repeat the Magic Number 9,2,4,9. 17/ Repeat Step 5. 18/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 645.999.9 MHz. 19/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 745.999.9 MHz. 20/ Repeat the Magic number of 9,2,4,9. 21/ Repeat Step 5. 22/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 745.999.9 MHz. 23/ Repeat Steps 1 and 2 Alternating Between both until you get the Frequency up to 845.999.9 MHz. 24/ Repeat the Magic Number of 9,2,4,9 in that order 25/ Repeat Step 5. 26/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 845.999.9 MHz. 27/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 945.999.9 MHz. 28/ Repeat the Magic Number of 9,2,4,9 in that order. 29/ Repeat Step 5. 30/ Repeat Step 6, And Tune to the Highest Frequency in the PMS, Which should be 945.999.9 MHz. 31/ Repeat Steps 1 and 2 Alternating Between Both until you get the Frequency up to 999.999.9 MHz, Be careful not to go Passed 999.999.9 MHz, Because the Rig automatically Default back to 945.999.9 MHz, And you will have to start again from that point. PAGE 3 Msg Nr. : 66071 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2340 Dimensione : 3793 Bid (Mid) : 36826_GB7WRG Titolo : MODS FOR FT736R UHF 1 OF 3 MODIFICATION OF THE PMS ON THE FT736R FOR 430 MHZ MOD 2 BY G0HEG Modification of the PMS on the FT736R for the 430 MHz Band, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 425 MHz to around 459 MHz. by the use of the Repeater shift, This gives a coverage of about 34 MHz, There is no need to snip any of the components, And you will not need a soldering Iron for this Modification. Instructions Make sure that when you start this Mod that you are in VFO A. Make sure that you put the Highest Frequency in to VFO B, and the Lowest one in to VFO A. Be careful not to Touch the UP or Down Scan Buttons on your RIG Whilst doing these Mods. Be careful not to Touch the Main Tuning knob on your RIG Whilst doing these Mods Please Note Also, Do not Press any scan Buttons on you FT736R, Do not Press the Channel Buttons or the Tuning Knob, Because if you Do Turn the Channel Knob the wrong way, you will lose all that you have done so far, What happens is this ( Press the wrong way the RIG will default back to 430 MHz. Turned the wrong way it will Default Back to 430 MHz Only Press or Turn Those Knobs Buttons or keys specified in these Mods. 1/ Turn on your RIG. 2/ Put the RIG into Repeater Shift for the 430 MHz Band, By pressing the + RPT KEY. 3/ Set the OFFSET to 09.999.9. 4/ Tune the RIG to the Lowest Band edge of 430.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. 7/ Repeat Steps 5 & 6 Nine Times more, Alternating Between Both until you get the Frequency down to 420.000.0 MHz. 8/ Increase the OFFSET to 19.999.9. 9/ Repeat Steps 5 & 6 Ten Times, Alternating Between both until you get the Frequency down to 410.000.0 MHz. 10/ Increase the OFFSET to 29.999.9. 11/ Repeat Steps 5 & 6 Ten Times, until you get down to 400.000.0 MHz. 12/ Increase the OFFSET to 39.999.9. 13/ Repeat Steps 5 & 6 Ten Times, until you get down to 390.000.0 MHz. 14/ Keep on Increasing the OFFSET by Ten, and after every Increase in the OFFSET, Repeat Steps 5 & 6 Ten Times, Until you get the OFFSET to 99.999.9, And the Digital Read out to 330.000.0 MHz. PAGE 1 Msg Nr. : 66066 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2258 Dimensione : 3662 Bid (Mid) : 36831_GB7WRG Titolo : MODS FOR FT736R UHF 2 OF 3 STAGE 2 Now that you have got so far it is Important that you follow the next few moves to the letter. 1/ Press the Function Key Which is Marked with an ( F ) 2/ Press the PMS KEY ( KEY 3 ). You have just stored your New Band Edges in to the PMS, to check this out simply Press the PMS KEY, and Press either of the up or down Scan Buttons, you will find that the RIG will scan up or down either way, but that Depends on which Button was Pressed first. Now that you have 330.000.0 MHz in the PMS, Make sure that you have an OFFSET of 99.999.9. in the PMS, also Make sure that the Repeater Shift is in the + RPT position. 3/ Tune to the Lowest Frequency in the PMS which should Now be 330.000.0 MHz. 4/ Press the REV KEY ( KEY 5 ). 5/ Press the UP MHz Button. 6/ Repeat Steps 5 & 6 Alternating Between both until you get your Digital Readout Down to 230.000.0 MHz. 7/ Press the Magic Number of 9,2,4,9 in that order. 8/ Press the F Key followed by the PMS key. 9/ Press the PMS Key again, Now tune to the lowest Frequency in the PMS Which should now be 230.000.0 MHz. 10/ Repeat Steps 5 & 6 Alternating Between both until you get the Frequency Down to 130.000.0 MHz 11/ Press the Magic Number of 9,2,4,9 in that order. 12/ Press the F Key followed by the PMS Key. 13/ Press the PMS KEY again, And Tune to the Lowest Frequency in the PMS, 14/ Repeat Steps 5 & 6 Alternating until you get the Frequency down to 30.000.0 MHz. 15/ Press the Magic Number of 9,2,4,9, in that order. 16/ Press the F KEY followed by the PMS Key. 17/ Press the PMS Key, Now Tune to the lowest Frequency in the PMS which should now be 30.000.0 MHz 18/ Repeat Steps 5 & 6 Alternating Between both until you get the Frequency down to 00.000.0 MHz, Be careful not to go Passed this Frequency, Because the RIG will automatically Default Back to 30.000.0 MHz, And you will have to start again from that point. 19/ Press the Magic Number of 9,2,4,9, in that order. 20/ Press the F Key followed by the PMS Key. PAGE 2 Msg Nr. : 66101 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0718/0149 Dimensione : 3666 Bid (Mid) : 36852_GB7WRG Titolo : MODS FOR FT736R 50 MHZ 1 OF 3 MODIFICATION OF THE PMS ON THE FT736R FOR THE 50 MHZ BAND MOD 3 BY G0HEG AND G0TVL I have not done this Modification, At the Time of writing I can not do this Modification, Because I do not have the 50 MHz Board in my FT736R, But I know of a Friend of mine who after a chat with me on 2 Mtrs, did this Modification on his RIG, It is one of the easiest of the Modifications for the FT736R. Modification of the PMS on the FT736R for the 50 MHz Band Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 46 MHz to around 56 MHz, By the use of the Repeater Shift, This give a coverage of about 10 MHz, But it may be Greater or Smaller than this, There is no need to snip any of the components, and you will not need a soldering Iron for this Modification. Instruction Make sure that you Put the Highest Frequency in to VFO B, and the Lowest one in to VFO A. 1/ Turn on your RIG. 2/ Put the RIG into Repeater Shift for the 50 MHz Band, By Pressing the + RPT KEY. 3/ Set the OFFSET to 01.999.9. 4/ Tune the RIG to the Lowest Band edge, of 50.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. You should now see 49.000.0 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 Once More, Alternating between both until you see 48.000.0 MHz on your Digital Readout, 8/ Increase the OFFSET to 03.999.9. 9/ Repeat Steps 5 & 6 Twice, This takes the Frequency to 46.000.0 MHz. 10/ Increase the OFFSET to 05.999.9. 11/ Repeat Steps 5 & 6 Twice, This takes the Frequency to 44.000.0 MHz. 12/ Keep on Increasing the OFFSET by 2, until you get the OFFSET to 51.999.9. 13/ at the same time as you Increase the OFFSET by 2, Repeat Steps 5 & 6 Twice after every Increase in the OFFSET, until you get 00.000.0 MHz on your Digital Readout. Be careful not to go beyond 00.000.0 MHz, Because the RIG will Automatically Default back to 50 MHz and you will have to start again, It is so frustrating when you lose so much of what you have already done. PAGE 1 Msg Nr. : 66007 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2029 Dimensione : 2535 Bid (Mid) : 36856_GB7WRG Titolo : MODS FOR FT736R 50 MHZ 2 OF 3 STAGE 2 Now you should have been using VFO A as the starting point, you should have 53.999.9 MHz in VFO B, and 00.000.0 MHz in VFO A. Press the Function KEY which is Marked with an ( F ), Followed by the PMS KEY ( KEY 5 ), You have Just stored your New Band Edges in to the PMS. Press the PMS KEY again, this time slowly Tune across the Two Band Edges, Until you see 999.999.9 MHz appear on your Digital Readout, Now whilst still in the PMS, Press the VFO B Button. These Next Few Steps Are Very Important 1/ Press The following KEYS ( KEY 9,KEY 2,KEY 4,KEY 9 in that order). The Magic Number is 9,2,4,9. 2/ Now Press the F KEY, followed by the PMS KEY. 3/ Press the PMS KEY again. You have Just stored the New Band Edges in to the PMS, you Should now have in VFO A, Which should be 00.000.0 MHz, and in VFO B, you should also have 999.999.9 MHz Press either of the UP of DOWN scan Buttons. You will now find that your FT736R will now scan up and down the Band from 00.000.0 MHz to 999.999.9 MHz, or from 999.999.9 MHz to 00.000.0 MHz. There are 3 other Mods for the FT736R, that you can do if your RIG as the Boards in it, Also there may be another Mod for the American 220 MHz Band but at the time of writing I do not know if it can be done. PAGE 2 Msg Nr. : 65956 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/1954 Dimensione : 1869 Bid (Mid) : 36860_GB7WRG Titolo : MODS FOR FT736R 50 MHZ 3 OF 3 List of Mods for the FT736R as found by G0HEG and G7OHY. Mod 1/ is for the 144 to 148 MHz band, - RPT Plus Down MHz Button, Frequency 139 to 155 MHz. Mod 2/ is for the 430 to 450 MHz Band, + RPT Plus Up MHz Button, Frequency 425 to 459 MHz. Mod 3/ is for the 50 MHz Band, + RPT Plus Up MHZ Button. Frequency 45 to 56 MHz ?. Mod 4/ is for the 1296 MHz Band, + RPT Plus Up MHz Button, Frequency 1215 to 1326 MHz ?. Mod 5/ is for the American 220 MHz Band, +/- RPT Plus UP or DOWN MHz Button, Freuqency ___ to ___ MHz ?. All these Mods are for Receiving only and can not be used to transmit on. The End PAGE 3 Msg Nr. : 66054 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2137 Dimensione : 3259 Bid (Mid) : 36871_GB7WRG Titolo : MODS FOR FT736R 220 MHZ 1 OF 2 MODIFICATION OF THE PMS ON THE FT736R FOR THE 220 MHZ BAND MOD 5 BY G0HEG Modification of the PMS on the FT736R for 220 MHz, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 215 MHz to around 230 MHz By the use of the repeater shift, This gives a coverage of about 15 MHz. There is no need to snip any of the components, And you will not need a soldering Iron for this Modification. Important notice Make sure that you put the Highest Frequency into VFO B, Make sure that you Put the lowest Frequency into VFO A. When you start this Mod make sure that you are in VFO A, Because this will save you a lot of work later on. Instruction 1/ Turn on your Rig. 2/ Put the RIG into Repeater shift for 220 MHz Band, by pressing the + RPT KEY. 3/ Set the OFFSET to 05.999.9. 4/ Tune the RIG to the lowest Band edge of 220.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz Button. You should now have 219.000.0 MHz on your Digital Readout. 7/ Repeat Steps 5 & 6 again Five Times More, Alternating between both Until you get 214.000.0 MHz on your Digital Readout. 8/ Increase the OFFSET to 11.999.9. 9/ Repeat Steps 5 & 6 Six Times More, Alternating Between both until you get 208.000.0 MHz on your Digital Readout. 10/ Increase the OFFSET to 17.999.9. 11/ Repeat Steps 5 & 6 Six Times More. 12/ Keep on Increasing the OFFSET by Six until you get the OFFSET up to 99.999.9. 13/ Keep on Repeating Steps 5 & 6 Six Times after every increas in the OFFSET until you Get the Frequency to 120.000.0 MHz. Now that you have 120.000.0 MHz in VFO A, you should also have 224.999.9 MHz in VFO B. PAGE 1 Msg Nr. : 66106 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0718/0157 Dimensione : 3514 Bid (Mid) : 36874_GB7WRG Titolo : MODS FOR FT736R 220 MHZ 2 OF 2 STAGE 2 1/ Press the F KEY followed by the PMS KEY ( KEY 3 ). 2/ Press the PMS KEY again, You have Just stored the New Band Edges in to your PMS, Now press either of the UP or DOWN scan Buttons on your RIG, and you will see your RIG scanning Between 120.000 0 MHz and 224.999.9 MHz, or 224.999.9 MHz to 120.000.0 MHz, But that Depends on which Button you Pressed first. Make sure that your RIG is in the + RPT position. 3/ Now Tune to the Lowest Frequency in your PMS, Which should be 120.000.0 MHz. 4/ Set the OFFSET to 99.999.9. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the DOWN MHZ BUTTON. 7/ Repeat Steps 5 & 6 Alternating Between both until you Get the Frequency Down to 20.000.0 MHz. 8/ Now Press the following Keys ( Key 9,Key 2,Key 4,Key 9 Again. The Magic Number is 9,2,4,9. You should now have 20.000.0 MHz in VFO A, And 224.999.9 MHz in VFO B. 11/ Repeat Step 1. 12/ Repeat Step 2. 13/ Now Tune to the Lowest Frequency in your PMS Which should be 20.000.0 MHz 14/ Repeat Steps 5 & 6 Alternating between both until you get the Frequency in the PMS to 00.000.0 MHz care should be taken not to go passed 00.000.0 MHz because the RIG will automatically Default back to 20.000.0 MHz and you will have to start again from That point. 15/ Now Press the Following KEYS (9,2,4,9 in that order). The Magic Number is 9,2,4,9. 16/ Repeat Step 1. 17/ Repeat Step 2. Now that you are in the PMS you should have 00.000.0 MHz in VFO A and 224.999.9 MHz, Whilst still in the PMS Tune across the Two Band Edges From 249.999.9 MHZ to 00.000.0 MHz until you see 999.999.9 MHz, on your Digital Readout. Now Whilst still in the PMS press the VFO B Button. 18/ Now Press the Following Keys( Key 9,2,4,9 in that Order ). 19/ Repeat Step 1. 20/ Repeat Step 2. You should now have 00.000.0 MHz in VFO A, and 999.999.9 MHz in VFO B. Now press either of the up or down scan Buttons, and you will find that your RIG will scan up or down depending on the Button you Pressed First. You will have to set your own Band edges on this Mod Because I am not allowed to have this board in My RIG Happy Scanning. De G0HEG PAGE 2 Msg Nr. : 66020 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2036 Dimensione : 3198 Bid (Mid) : 36863_GB7WRG Titolo : MODS FOR FT736R 1296 MHZ 1 OF 2 MODIFICATION OF THE PMS ON THE FT736R FOR THE 1296 MHZ BAND. MOD 4 BY G0HEG Modification of the PMS on the FT736R for 1296 MHz, Extended coverage on receive from the front panel can be achieved by means of a few simple but repetitive actions, The receive can be extended from about 1215 MHz to about 1326 MHz, by the use of the Repeater shift, This gives a coverage of about 111 MHz. There is no need to snip any of the components, and you will not need a soldering Iron for this modification. INSTRUCTIONS Make sure that you put the Highest Frequency into VFO B, Make sure that you put the Lowest Frequency into VFO A. 1/ Turn on your RIG. 2/ Put the RIG into Repeater shift for the 1296 MHz band, By pressing the + RPT KEY. 3/ Set the OFFSET to 59.999.9. 4/ Tune the RIG to the Lowest band edge, of 1240.000.0 MHz. 5/ Press the REV KEY ( KEY 5 ). 6/ Press the UP MHz BUTTON. 7/ Repeat steps 5 & 6 Alternating between both until you get the Frequency down to 1180.000.0 MHz. 8/ Increase the OFFSET to 99.999.9. 9/ Repeat steps 5 & 6 Alternating between both until you get the Frequency down to 1140.000.0 MHz. STAGE 2 You should now have 1299.999.9 MHz in VFO B, And 1140.000.0 MHz in VFO A. Make sure that the OFFSET in the PMS is set at 99.999.9. Make sure that you have the Repeater Shift set in the + RPT position. 1/ Press the F key followed,by the PMS KEY ( KEY 3 ). You have just stored the New band edges in your PMS. 2/ Press the PMS KEY again, now Tune to the Lowest Frequency in the PMS. Which should now be 1040.000.0 MHz. 3/ Press the REV KEY ( KEY 5 ). 4/ Press the UP MHz BUTTON. 5/ Keep Alternating between steps 3 & 4 until you get the frequency down to 1040.000.0 MHz. 6/ Now Press the following KEYs( KEY 9,KEY 2,KEY 4,KEY 9 ). The Magic Number is 9,2,4,9. You should now have 1040.000.0 MHz in VFO A. 7/ Repeat Step 1. PAGE 1 Msg Nr. : 66048 Da : G0HEG Per : MODS @WW Tipo/status : BF Data/ora : 0717/2114 Dimensione : 2952 Bid (Mid) : 36867_GB7WRG Titolo : MODS FOR FT736R 1296 MHZ 2 OF 2 8/ Repeat step 2, and Tune to the lowest Frequency in the PMS. 9/ Repeat step 3. 10/ Repeat step 4. 11/ Keep Alternating between steps 3 & 4 until you get the Frequency down to 1000.000.0 MHz, becareful not to go over 1000.000.0 MHz, because the RIG will Automatically Default back to 1040.000.0 MHZ, and you will have to start again from that point. 12/ Repeat step 6. 13/ Repeat step 1, By Pressing the Function KEY, Followed by the PMS KEY ( KEY 3 ). 14/ Repeat step 2, Press the PMS KEY and Tune across the Two band edges, until you see 1999.999.9 MHz on your Digital Readout, 15/ Now whilst still in the PMS press the VFO B Button. 16/ Press the Magic Number of 9,2,4,9. 17/ Repeat step 1. 18/ Press the PMS KEY, But this time Press either of the UP or DOWN scan buttons, Your RIG will now scan between 1000.000.0 MHz and 1999.999.9 MHz or 1999.999.9 MHz to 1000.000.0 MHz. As stated at the begining of this Modification the RIG will Receive from about 1215.000.0 MHz to around 1326.000.0 MHz. This Modification is for Receiving only, you can not use it to transmit outside your allowcated Frequency. the End of Mod 4 There are 3 more Mods for the FT736R, One for every Band that it will Receive on. HERE IS THE LIST MOD 1. 144 TO 148 MHz - RPT plus Down MHz Button, the OFFSET is 01.999.9. MOD 2 430 TO 458 MHZ + RPT plus Up MHz Button, the OFFSET is 09.999.9. MOD 3. 46 TO 56 MHz + RPT plus Up MHz Button, the OFFSET is 01.999.9. MOD 4 1215 to 1326 MHz + RPT plus Up MHz Button, the OFFSET is 59.999.9. MOD 5 215 to 230 MHz + RPT plus Up MHz Button, the OFFSET is 05.999.9. THE END ÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛ Subj: FT 736R Extended Frequency coverage. I've received the modification information for the aforementioned radio. Remember, this is for CAP/MARS use only - Amateurs are NOT permitted to transmit outside of the Amateur bands without specific authorization. The mods take place on the 144 main unit (No. 6XXX). The diode array is in the lower left corner of the board, component side towards you, and the notches to the left. No information was given as to diode type, but I assume any small signal diode will work. D24 D25 D26 D27 X=Omit O=Installed ___________________ | | | | | | X | O | O | X | 144.0 - 148.0 (Standard US) |____|____|____|____| | | | | | | X | O | O | O | 141.0 - 154.0 (Extended Rx/Tx) |____|____|____|____| | | | | | | X | X | O | O | 144.0 - 146.0 (Non US) |____|____|____|____| ----------- Jon Maguire N1CQE/4 Tampa, FL 33607 ÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛ