[R-390] Penultimate recapping an R-390A

[2002tii]

Jerry wrote:

>Whatever trips his trigger... but if I was going to all that trouble I
>think I'd have at least started with a St. J refugee or similar needy
>derelict instead of this nice looking SW--which probably didn't really
>need tearing down.

Indeed.  Some might say that using steel wool on the chassis and 
removing the Alodine finish was defacing the radio.  Not to mention 
all of the tiny steel particles that remain embedded in the aluminum, 
which will eventually rust and make it genuinely ugly.  (Metalworkers 
know better than to use steel wool on aluminum, for just this reason.)

>I do agree that a product detector mod or accessory
>product detector is just a frill for these receivers. The 390A is so
>stable that just tuning the BFO for clean SSB audio always worked
>perfectly for me.

The problem isn't instability or lack of a product detector, it is 
the low BFO injection.  This can be much improved by increasing the 
BFO injection capacitor and re-tuning the BFO neutralization.  I 
wouldn't say it works "perfectly" compared to, say, a 51S-1, but it 
does work just fine.

Best regards,

Don


Copyright (c) 2011.  Not for redistribution