Collins Designed R390A/UUR Military Reciever
The Collins designed, R390A/URR general coverage HF radio receiveris considered to be the finest HF radio receiver ever built. Tuning .5 to 31,999 mhz and employing 21 vacuum tubes and weighing in at 85 lbs, this electro-mechanical wonder was designed in the early 50’s and released for military use on February 24, 1954. Thanks to features such as a 6DC6 first RF amplifier, a suite of 4- Military Grade Collins mechanical filters teamed up with full tracking RF and IF sections, the R390A is capable of copying AM and CW signals down to its -143db noise floor, close to the galactic limit. All this while maintaining the capability to operate in high overload, strong signal environments…
Detailed Technical Manual covering the operating, theory of operation, troubleshooting, maintenance, and much more. If you ever wanted to know what is inside one of these 85 pound military monsters, then this is the manual for you. 309 pages.
R-390A/URR Technical Reference
A R-390 in action – makes a nice 85 pound desktop broadcast AM reciever
These radios regularily show up on e-bay