Adam looks like a potential mod for SSB.
previous owner may have installed the LEE 6BE6 mod in place of the 6BA6
for the BFO.
you will need to pull the coupler and take a look underneath. probably
the mod is not 100% self contained in the IF Deck.
IMO 6BE6 or 6BY6 are not great tubes for SSB too much distortion for me,
I currently use a 12AU7 PD in place of the reg tube. ( I current
regulated the fil for BFO/VFO tubes), PD Article to follow soon.
my AGC mod is Hatch.
re the switch, original is B+ for the BFO on/off so if it will do that
you will be ok.
Renée, K6FSB
On 10/8/25 12:43 AM, Adam Morehouse wrote:
I might have found the issue.
Can anyone tell me if the white coax in the follow pictures is supposed to
be there?
https://photos.app.goo.gl/M6Qcr9mXFrZ6sgiRA
It doesn't look original to me, nor does the the resistors and caps in
front of the BFO. They seem to be hooked to V508 and RT512.
On Tue, Oct 7, 2025, 16:55 Adam Morehouse <[email protected]> wrote:
Hey guys,
I appreciate the pointers on my R-392, and now that it's buttoned up, it's
time to work on my R-390. I only tested this briefly when I first got it,
today I threw it up on the bench. Supposedly this was restored by Rick
Mish, it is very clean (except the gear train, which has a lot of fresh
grease...), and the front panel is pristine.
It does pull stations, but the volume is extremely low in AGC mode, and
gets slightly louder when placed into MGC.
In MGC, with the BFO switched on, it plays at a normal (not super loud,
but loud) volume.
In AGC, with the BFO switched on, it hums, low volume audio.
The limiter seems to have no effect, and varying the BFO doesn't do
anything at all no matter AGC/MGC.
I have Tom's solid state kit installed, and B+ at the AF deck test point
is a steady 180.5vdc.
I am going to dig out the TM's later on, I have them somewhere...but maybe
somebody here can help point me in the right direction.
Thanks!
Adam K2AAM
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