I've changed all the electrolytic caps and power resistors and it's now back to life with good sensitivity. Still some problems including strong hum (other GR-54 owners have reported this problem and there ought to be some way to remedy this). The tuning meter deflects negative; meter adjustment pot is good but has no effect; problem in the AGC Circuit (bad diodes?). And the BFO is not functional. All the tubes test good and the audio output tube is new. Any suggestions would be much appreciated!

Dan:
There are several sites out there about mods to your radio.
Start here and follow some links listed in this article too.
http://unforgettability.net/content/page/projects_gr54/

Thanks Peter. I was aware of the various mods to improve the GR-54 which is exactly the reason I recently went out and purchased one. I love the idea of making a silk purse out of an old sow's ear!

Poking around inside I've discovered that most of the resistors have drifted upward in value and I'm in the process of replacing them all. I've already replaced the RF Amp and the 1st IF Tubes with 6DK6's and changed the cathode bias resistors as required. Too early to say how much this helped because the whole receiver will have to be re-aligned once I'm done with everything.

A GR-54 enthusiast in Tempe Arizona writes that the only way to eliminate the annoying hum in the GR-54 is to copy the audio circuit components of the Heathkit HW-16 into the GR-54 (IE - remove the resistors and capacitors in the GR-54 audio section and use the same values as found in the HW-16). Both Radios employ the 6HF8 tube for audio but the HW-16 audio section is better designed.

Hopefully the other problems in my GR-54 will clear up as I continue to replace the old resistors.

:Dan:
:There are several sites out there about mods to your radio.
:Start here and follow some links listed in this article too.
:http://unforgettability.net/content/page/projects_gr54/
: