[R-390] 390() vs 390(A)

[Paul H. Anderson]

On Sun, 26 Dec 2004, Barry Hauser wrote:

> Hi John & list
>
> There is also the R-391, which is basically the same as an R-390 with an
> electromechanical autotune mechanism added.  There is an extra 8-channel
> knob, little window showing the current channel and special MC and KC
> knobs with locking keys.

Don't forget the R-389, which is about as much alike as it is different.
The frame is very similar to the R-390 frame (maybe the same, I haven't
looked real closely yet), and uses the same IF, AF and PS.  Early R-389's
used a PS with different output B+ wiring.  Supposedly these were
retrofitted so that PS's were compatible across the R-389/R-390 and R-391
(MOD-1, I think).

The VFO and RF decks of the R-389 are very different, and there is a
rectifier stack for producing DC for the R-389 tuning motor.  Oddly, the
R-391, which also has a DC motor for tuning, doesn't have the rectifier
stack.  There probably wasn't room, if I had to guess.

Paul