Felton Electronic 
Design,Short Wave Radios, 14V DC Generators, Portable Antennas, 
Transceivers, High Efficiency Precision Speakers
The R390A is already a magnificent synthesis of electronics and mechanical design. The KD0ZS R390F, freed from military contract constraints and optimized for wide range of HAM and SWL interests, finishes the job. Made to order and Made in America. Upgrades are hand wired with parts like original. It's not a different radio, just better, much better.

2 watts of hi-fi audio drive a very efficient 12" coaxial speaker in a tuned wood box. Your ears are protected by four front panel selected audio filters and the limiter optimized for both A.M. and S.S.B. Line channel drives stereo headphones.

Modern automatic gain control is redesigned, both rise and fall times for AM ,or with BFO for SSB/CW. Adjusted gain and AGC voltage distribution, staggered AGC attack times, the much improved 6BZ6 front end tube and corrected pentode screen voltages all contribute to wildly improved dynamic range.

I.F. bandwidths:
  • 350 cycle BW crystal for CW
  • 1.7 Kc crystal backed up by 2.0 Kc mechanical for noisy SSB
  • 2.0 Kc mechanical for SSB (8 pole crystal available)
  • 4.0 Kc mechanical for HAM AM or full response SSB
  • 8.0 Kc mechanical, the default SWL bandwidth
  • 16.0 Kc 6 pole L.C. minimum phase shift for highest fidelity.
  • 2 new, non-radioactive, American made, much better visibility meters with "S" scale.

For more details, options and pricing call:

Chuck Felton KD0ZS
For a test drive come to:
Felton Electronic Design
1115 South Greeley Highway
Cheyenne, Wyoming 82007
By appointment only


  Felton Electronic Design offers:
  • Low Noise, high dynamic Range R.F. design.
  • Communications and E.M.I. consulting.
  • Phase noise design analysis.
  • Custom instrumentation.
Devices available on production basis.
Choices of packaging available

  • Low noise oscillators, multipliers, limiting amps.
  • Low noise, broadband, isolation & distribution amps.
  • (100kHz - 150MHz)Phase noise detectors.
Repair, upgrade, performance modification of tube communications and test equipment. Accepting most military, all Collins & Drake designs, and the better efforts from others. Laboratory performance documentation on request. Our work is guaranteed! KD0ZS


Contact Felton Electronic Design by
emailing us at: feltondesign@yahoo.com
or by writing to:
Chuck Felton KD0ZS
Felton Electronic Design
1115 S. Greeley Hwy
Cheyenne, Wy. 82007