The R-390/URR is the general-coverage HF receiver that Collins designed for the US Army Signal Corps in the early 1950s. It covers 0.5 to 32 MHz in thirty-two 1 MHz bands, with a mechanical digital frequency readout. Its IF selectivity comes from tuned circuits and a crystal filter, not the mechanical filters of the later R-390A.
R-390 articles on this site
- The Collins R-389, R-390 and R-390A
- Crystal Filters & Mechanical Filters — A-Line Receivers, KWS-1, R-388, R-390 & R-390A Collins – IF Selectivity Filter Master Reference
- R-390/URR Failure Prevention Kit — Component & Modification Design
- Collins R390 Receiver Restoration Guide
- Collins R-390 vs R-392 technical comparison (PDF)
Related receivers: R-388/URR · R-389/URR · R-390A/URR · R-391/URR · R-392/URR
Mike Peace VK6ADA / r-390a.net and foxtango.org Administrator