I am the proud owner of this Collins designed R390A/URR general coverage, HF radio receiver. In many circles, the R390A is considered to be the finest HF radio receiver ever built. Weighing in at 85 lbs, this electro-mechanical wonder was designed in the early 50's and released February 24, 1954. Thanks to features such as a 6DC6 first RF amplifier, a suite of Military Grade Collins mechanical filters and full tracking RF and IF sections, the R390A is capable of copying signals down to its -143db noise floor, close to the galactic limit. All this while operating in high over load/strong signal environments.
Originally built by Collins Radio Company in Cedar Rapids, IA, the R390A was designed by 2 teams. The mechanical team being lead by Fred Johnson while the electronics team was overseen by Ernie Pappenfus, K6EZ. Besides Collins Radio, there were 13 other sub-contractors which built R390A's until the last one rolled off the assembly line in 1984. Banks of these fine radios served the country in all branches of the military and also the CIA and NSA for monitoring communications from behind the Iron Curtain during the Cold War years where the R390A was classified TOP SECRET until the mid-1960's. Stories are told that R390A's are still in use by the NSA where senior operators far prefer their quiet, yet stellar performance over modern, mega-dollar receivers from Harris, Racal and Watkins-Johnson.
This radio has been completely restored. It set inside a specialized Hammond rack cabinet and is cooled by an automated AC Infinity fan set. It is pictured here with the Oneida LS-206A/U rack mount dual speaker which was the original the matching military set for the Collins R-390A receiver.
Originally built by Collins Radio Company in Cedar Rapids, IA, the R390A was designed by 2 teams. The mechanical team being lead by Fred Johnson while the electronics team was overseen by Ernie Pappenfus, K6EZ. Besides Collins Radio, there were 13 other sub-contractors which built R390A's until the last one rolled off the assembly line in 1984. Banks of these fine radios served the country in all branches of the military and also the CIA and NSA for monitoring communications from behind the Iron Curtain during the Cold War years where the R390A was classified TOP SECRET until the mid-1960's. Stories are told that R390A's are still in use by the NSA where senior operators far prefer their quiet, yet stellar performance over modern, mega-dollar receivers from Harris, Racal and Watkins-Johnson.
This radio has been completely restored. It set inside a specialized Hammond rack cabinet and is cooled by an automated AC Infinity fan set. It is pictured here with the Oneida LS-206A/U rack mount dual speaker which was the original the matching military set for the Collins R-390A receiver.