Yaesu FT736R Transceiver. - UK Vintage Radio Repair and Restoration Discussion Forum

g0hze snowy · 9th Mar 2024, 8:34 pm

Hi peps, i have recently purchased the above t/rx, whilst it seems to be working according to my test setup, power/frequency and mic mod output i was unable to open my local repeater using the correct ctcss tone.
I did however notice that whilst in the transmit mode i noticed that both the tx/rx led,s were illuminated.
has anybody come across this problem and its cure.
Is there a bit of test kit that can identify the ctcss tone being transmitted?. my mod meter 9008? shows transmitted audio output without any input from the mic, would that be the ctcss amplitude?.
Any and all help appreciated. TIA.

Terry_VK5TM · 10th Mar 2024, 12:28 am

The 736R is notorious for power supply problems - bad electro caps - so that might be a possibilty.

For interest, info on replacing the power supply with a more efficient unit is here https://gm8bjf.joomla.com/articles/2...e-yaesu-ft736r

To measure the CTCSS frequency, best would be to get inside and check at the point where it is generated first (haven't looked at the manual, so can't say "test at this component").

ex seismic · 10th Mar 2024, 9:23 am

Lots of cheap wee VHF handheld frequency counters out there that display frequency and CTCSS.

g0hze snowy · 10th Mar 2024, 10:15 am

Good morning Tel, thanks for your advice, have to say that the PSU in the 736 is as new, i was at the end of rebuilding a spare that i have with new caps, 'R's etc, when i unscrewed the cover to change the unit i found that it had already been done. a bonus.
Now onto ex-seismic, who hails from my home county, Paddock Wood to be precise, i will look at the various radios with that on board, thanks

marlowradio · 11th Mar 2024, 11:41 am

Does it have the CTCSS Board fitted as the FT736R didn't have them fitted as standard

Many Thanks
Steve

g0hze snowy · 11th Mar 2024, 8:49 pm

Hi Steve, have fitted the CTCSS module, didn't check to see if I had the problem in the 1st instance, busy LED seems to flash on voice peaks, thought it may be due to ALC but I have had good audio reports so I am not over-driving the mic circuit. Changed the control board after cleaning the glue that held the button cell in place, I understand that it goes conductive in its old age.

g0hze snowy · 29th Mar 2024, 11:22 am

update on the 736, ctcss now working, also another user of the 736 has stated that his 3 ? radio's all do the same, so a peculiarity with these radios.
cheers and beers, Snowy

9th Mar 2024, 8:34 pm	#1
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 341	Yaesu FT736R Transceiver. Hi peps, i have recently purchased the above t/rx, whilst it seems to be working according to my test setup, power/frequency and mic mod output i was unable to open my local repeater using the correct ctcss tone. I did however notice that whilst in the transmit mode i noticed that both the tx/rx led,s were illuminated. has anybody come across this problem and its cure. Is there a bit of test kit that can identify the ctcss tone being transmitted?. my mod meter 9008? shows transmitted audio output without any input from the mic, would that be the ctcss amplitude?. Any and all help appreciated. TIA.

10th Mar 2024, 12:28 am	#2
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,347	Re: yaesu ft736r The 736R is notorious for power supply problems - bad electro caps - so that might be a possibilty. For interest, info on replacing the power supply with a more efficient unit is here https://gm8bjf.joomla.com/articles/2...e-yaesu-ft736r To measure the CTCSS frequency, best would be to get inside and check at the point where it is generated first (haven't looked at the manual, so can't say "test at this component"). __________________ Terry VK5TM https://www.vk5tm.com/

10th Mar 2024, 9:23 am	#3
ex seismic Heptode Join Date: Sep 2009 Location: Tonbridge, Kent, UK. Posts: 689	Re: yaesu ft736r Lots of cheap wee VHF handheld frequency counters out there that display frequency and CTCSS.

10th Mar 2024, 10:15 am	#4
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 341	Re: yaesu ft736r Good morning Tel, thanks for your advice, have to say that the PSU in the 736 is as new, i was at the end of rebuilding a spare that i have with new caps, 'R's etc, when i unscrewed the cover to change the unit i found that it had already been done. a bonus. Now onto ex-seismic, who hails from my home county, Paddock Wood to be precise, i will look at the various radios with that on board, thanks

11th Mar 2024, 11:41 am	#5
marlowradio Triode Join Date: Jun 2011 Location: Marlow, Buckinghamshire, UK. Posts: 34	Re: Yaesu FT736R Transceiver. Does it have the CTCSS Board fitted as the FT736R didn't have them fitted as standard Many Thanks Steve

11th Mar 2024, 8:49 pm	#6
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 341	Re: Yaesu FT736R Transceiver. Hi Steve, have fitted the CTCSS module, didn't check to see if I had the problem in the 1st instance, busy LED seems to flash on voice peaks, thought it may be due to ALC but I have had good audio reports so I am not over-driving the mic circuit. Changed the control board after cleaning the glue that held the button cell in place, I understand that it goes conductive in its old age.

29th Mar 2024, 11:22 am	#7
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 341	Re: Yaesu FT736R Transceiver. update on the 736, ctcss now working, also another user of the 736 has stated that his 3 ? radio's all do the same, so a peculiarity with these radios. cheers and beers, Snowy