Dr. Gregory L. Charvat

Antique Radio Restorations

R390A, the Best Receiver of the Tube Era

Purchased this at Dayton in 2013 for a very low cost of $150 due to a rainy day.  I was able to repair the receiver in one day.

Some tricks:

  • To match the 600-ohm audio output to a modern 4-ohm speaker I used a 12V transformer.
  • To prevent the GFCI outlet in my basement from tripping every time I plugged in the radio I had to bypass the OEM power entry module, using 0.01uF safety bypass caps across the line.
  • I developed a scheme to transmit SSB with this radio by splitting the VFO output (which is fairly high power), feeding half of it to a VFO frequency converter. The output of this converter feeds directly to a 5 MHz VFO input on a 20m SSB radio that I developed. So now the R390A tunes my 20m SSB transmitter allowing me to transmit back to those stations I tune in on the R390A. An article on this will be published soon in QST hints and kinks.

More Radios

Retro ‘Boom Box’ using an Emerson Pioneer 888 Transistor Radio

Sears Silvertone
Model 4686 art
Deco Console Radio

A Retro ‘Boom Box’ (with Ipod Doc) Using a 1946 Olympic Model 6-606 Battery/AC Radio


Colin B. Kennedy Model 20 B Console Radio

WWII ARC 5 Command Receiver, CBY-46104.

RCA Radiola 18

Restoration of a Hallicrafters S-76 Communications Receiver

Restoration of a Zenith K725 (chassis 7K01) AM and FM Broadcast Band Radio