U.S. Navy R-390A

Manufactured 1954 through 1984, Cedar Rapids, IA

Retail (1954): $2500

Type: General Coverage HF Communications Receiver

 

The Collins-designed R-390 is considered by many to be the ultimate tube-type HF receiver. This evolutionary end of the line began with the the 75A-1 ham-band receiver, designed after World War II, continued through the 51-J series (equivalent to the military R-388),  culminating in the R-390 and R-390A.

 

The development of the revolutionary Permeability Tuned Oscillator (PTO), combined with a mechanically complex mechanism, led to an extremely stable receiver with a “slot machine” digital frequency readout. The receiver was ideal for HF radioteletype and crypto applications at data rates up to 150 bits per second.

 

The production of new R-390A receivers continued into the early 1970‘s, and a number of units were remanufactured to new specifications in the final contract let in 1984. Over the years, many companies received R-390 production contracts, and an estimated 90,000 units were produced. My R-390A was manufactured by Teledyne in 1962 for the U.S. Navy.

 

During the 1991 Gulf war, R-390s were hastily located and shipped to the region for active duty when high failure rates plagued the modern microprocessor-controlled solid-state radios. The Sacramento Army Depot is still holding several hundred refurbished R-390A radios in inventory, but most others ha ve been removed from active service and surplused out.