[R-390] EAC R-390 factory modification that incorporates USB/CW/LSB

[Dave Merrill]

Some months ago I contacted Paul Keys of Columbia Electronics to see
if they still had the circuit diagram on file and received this reply:

11-18-06
Dave,

I looked for the diagram of the SSB Modification and could not find it.

I remember that it was a small one tube chassis with a crystal that
mounted behind the front panel.  The mode switch also had an extra
position.

Sorry that is all that I can provide.

-- 
Best regards,

Paul Keys, President


On 6/3/07, Tim Shoppa <shoppa_r390a at trailing-edge.com> wrote:
> "TChirhart" <sparks at codepoets.com> wrote:
> > Does anyone know any anyR-390's that were modified under contract that
> > removed the BFO on/off switch and replaced the BFO pitch control with one
> > control?  I saw an R-390A, EAC contract that had this modification. A
> > vertical 1 inch by 3 inch matching grey panel plate was installed over the
> > two switches and only one control remained. It had a LSB CW USB position
> > where the BFO pitch control previously was located. The owner indicated that
> > this was a rare factory modification. Sorry no photos were taken. So was
> > there ever a modification of this nature that was not an aftermarket add on?
> >
> > 73
> >
> > Tom K4NCG
>
> If this has a 6U8 added as well behind the front panel, isn't this
> the "Mexican Military" version by Columbia Electronics?
>
> Tim.