Yaesu FRG 7700 audio and mode pot fault fix

A while back and in July 2012, I asked Sam of Yaesu UK to send me a new audio pot for the Yaesu FRG7700 communications receiver. It got lost in the post and ended up being returned in its unopened package and back to the UK.

Its here now (thanks Dion)  but unused, as checking on Google I found a method to try to fix it which worked 100% and without removal of the pot. The fault then was the sound was either all on or mainly off, it was hit and miss as the knob was turned.

I had a look on Google and found a guy who used a thin oil to lubricate the back of the audio control which fixed the problem, I tried the same fix and it worked.

This set has the optional FRT 7700 tuner and memory pack on the rear of the set.

http://www.youtube.com/watch?v=ZrtN5dkvIEY

Check the link, its simpler that one would think to service this radios faults.

The original brochure came from Hamrad in Cape Town, back then the set was R529.20!

The manual tells me that the three positions on the Mode switch are selective for the AM bands, M being the normal choice when station signals are strong, for sure the audio is far clearer on that position.

I have owned this Yaesu FRG7700 at least twenty years, my old pal Willie (r.i.p) sold it to me after his last transatlantic crossing on his Lello 34 named Bucaneer.

Yesterday I got to thinking the same fix on the Mode pot may work also?

Check the link, its the same fault issue as the one my set had, note I say had!

After servicing of the two pots mentioned and tuning in to Cape Talk 567 I find the reception to be sparkling.
Also check the back of the set, you will find a black slide switch with Local and DX below and above it, squirt some thin lubricant into that switch also, you audio may increase just because of that.

For normal listening use the DX position.

I also see a posting saying that if your FRG7700 set has a serial number starting with 1H the set is dated August 1981, mine has a serial number starting with 2H1 (willie wrote this on the service manual) so is the set in the pictures later? They stopped production in 1982??

Roy

About 2018 the set died, went silent, no display now sound, nothing, I put it away on a shelf, then a few days back I got it out again, bought some circuit cleaner, sprayed all the knobs and guess what, success.

This fix may be of interest to many of the groups members, as what worked on my radio receiver may well work on receiver amplifiers also?

I have had a Yaesu FRG 7700 radio receiver for at least thirty years, I was the sets second owner, it came of a yacht that belonged to a friend of mine who had done at least two transatlantic crossings with the set.

In 2012 the audio knob had an issue, either all on or all off, thinking that the fault was the audio / tone control knob I imported a new one from England, before fitting it I tried a squirt of thin oil into the back of the control, it may have been Q20? the audio volume level then worked and the new one was never fitted.

A year back the set died, it just went silent, nothing at all to be heard, excepting when the power button was pressed a soft sound could be heard as the power went into the PCB.

I could have the set seen to by a radio specialist, however his hourly fee would soon pass the value of the set, I had an idea to see what an application of circuit cleaning fluid would do first?

The can of fluid cost me R139, its imported so far from cheap, say U$10.00 which I guess is cheap when you think about it?

I opened the set, sprayed all the control knobs as best as I could, the silence continued, I thought at the time "oh well nothing ventured nothing gained " as they say?

A while later I switched the set on and it came to life and with so much volume that I near fell off my chair, the set is fine now, audio and tuning all work.

Recomended, next I need to install new light bulbs in the SWR meter and tuning dial.