[R-390] R-390 vs R-392?

[Bob kb8tq]

Hi

Way back in time, I ran the R392’s along with R390’s and R390A’s. 

The 392 was not as much fun to use. The 28V supply did indeed create issues. The
audio end of things was impacted pretty heavily. The tuning mechanism was not quite
as good for “ham use” as the R390 or R390A.

Bob

> On Mar 3, 2026, at 5:15 PM, James A. (Andy) Moorer <jamminpower at earthlink.net> wrote:
> 
> Has anybody done a comparison between the R-390 and R-392 performance? I know the 392 is de-featured (one audio output, fewer BW choices), but has anyone just compared apples to apples? That is, set the 390 and the 392 to the same station, using the same antenna, same settings? I have gone over the schematics pretty carefully and I don't see any difference in the core signal handling. The 26A6 tubes have perfectly reasonable behavior and have equivalent bias, screen grid, noise figure, and so on. So, do they sound any different?
> 
> I noticed two other things - the IF output for the 392 is a wreck. Seems to be half-wave rectified. Lot of nonlinearity there. And the audio output stage is quite different from the 390. That all-important IF stage appears to be identical to the 390.
> 
> So - what's the story?
> 
> -A
> 
> -- 
> James A. (Andy) Moorer
> www.jamminpower.org
> 
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