[R-390] R-390a Solid State Conversion

[Mack McCormick]

This list has helped me immensely over many years and I’d like to share my
latest project to covert a R-390a to Solid State. First, this design
belongs completely to Charles Smith, KV4JT. I saw his conversion video on
YouTube and it looked like a fun project. Charles and I correspond
frequently with my lessons learned during the conversion and his continued
improvements.  There have been two major revisions after the original video.

Also, I tend to be a purist with vintage restoration and never make
permanent modifications to the original designs. I have seven R-390a’s,
R-390, and R-391 in the shack. All loving restored to original design.

The changes made to this solid state conversion are all reversible if
desired. This rig started with a basket case parts radio that I paid $25
for. I took parts/modules from other parts radios I own.  It was a fun
project and I took a different approach by designing Tubelet boards and
tube bases as replacements.

It works exceptionally well in A/B swaps with a blueprinted R-390a. The
test equipment specs are great.

Anyway, sorry for the long introduction but here are some photos of my
conversion for you to review.
https://photos.app.goo.gl/11AjyNCi2zV3T8LaA  You may also want to watch
Charles’ videos on YouTube. The conversion documents he sells for a very
modest price are superior.


Vy 73,

Mack
W4AX
-- 

73,

Mack
W4AX
https://www.qrz.com/db/W4AX