The R-390A Frequently Asked Questions Page


Collins Radio Company did all of the research and development for the R-390A/URR under a government contract. A large number of organizations manufactured the R-390A, variants of it, and accessories for it.

Many small companies manufactured R-390A/URR equipment under government contract. These companies assembled equipment to the specifications that Collins created. The companies often closed when a contract was complete and reopened with new name if another contract came along.

Les Locklear has documented a history of several of these companies in his articles in Electric Radio Magazine and in his postings to the R-390 mailing list. It has descriptions of most articles about the R-390 series of receivers and related equipment in issues 1 through 119.

Tom Marcotte, N5OFF has been diligently amassing data for several years regarding the contract numbers, manufacturers, and quantities of receivers produced in the R-390 family. His efforts are very much appreciated and can be found on our website at contract numbers.

This document is a compilation of the wisdom shared by members of the online community of R-390A enthusiasts. As such, it is advice to those who endeavor to maintain and restore the R-390A family of receivers.

The information is shared without warranty, expressed or implied. This information is in the public domain and can be freely copied or shared. Appropriate attribution is appreciated.

Les Locklear reported that Ben Adler founded Adler Electronics Corporation in New Rochelle, NY. They are not known to have built R-390(*) receivers themselves. The Adler-tagged receivers that exist state that they were manufactured by Capehart Corporation for Adler Electronics.
Amelco manufactured about 2,500 R-390A's for this order under contract DA 36-039-SC-79620. The contract was for 5,000 receivers, but Teledyne acquired them in early 1963 and the rest of the contract was under Teledyne. All units were made at the Panama Street location in Culver City (by Los Angeles).
Arvin Industries manufactured the IF subassemblies for the R-725 variant of the R-390A used by the military for direction finding work.
Les Locklear reported that Capehart Corporation was located in 1969 at the same address in Richmond Hill, New York as Clavier. The head of Capehart, Gerry Loecher, was also the head of Clavier and Fowler Industries. Capehart manufactured opulent home entertainment systems in the 1930's and jukeboxes in the 1920's and 1940's.  They also made TVs in the early 50's.
Les Locklear reported that Clavier Corporation located in 1969 at the same address in Richmond Hill, New York as Capehart. He said that the head of Clavier was also the head of Capehart and Fowler.

Collins designed the R-390A receiver, but actually made relatively few of them. The Collins R-390A receivers manufactured under the first contract (14214-Phila-51) cost the government $2,210 each in 1951.  Due to normal initial design, engineering and production setup, the first delivery was in 1953. 
In November, 1998, Mike, KC8CU reported finding an R-390A where the BFO control had been replaced by a 4-position switch marked LSB-USB-AM-CW. A 6U8 product detector circuit had been added behind the new mode switch. This specimen appeared to have been based on a modified 1967 EAC unit from contract DAAB-05-67-CO15 by Columbia Electronics, Inc. of North Hollywood, CA. Columbia Electronics' owner confirmed that they had indeed modified 30 R-390A receivers for SSB for the "Mexican military".

Commuinications Systems did not build R-390A receivers. They built subassemblies.

Dittmore-Freimuth did not manufacture R-390A receivers themselves. They bought EAC units and replaced the nameplates with their own.

Electronic Assistance Corporation (EAC) was the name of a subsidiary company operated by Hammarlund Manufacturing. EAC advertised a limited quantity of R-390A/URR receivers for sale to the public for $1,700 in 1970.The commercial specification appeared identical to the Military specification and these receivers were apparently excess from a military contract. Hammarlund also listed the R-390A in their dealer price sheets. The price posted in Jan 1970 for a single unit was $2266.00 and for more than 16 units as $1700.00. These receivers had an "EAC Rocket" name tag. Hammarlund originally located in the New York City area, but moved to the Mars Hill, NC area in the 1970's before ceasing operation.
Fowler Industries apparently emerged from the company that was originally Clavier Corporation. Les Locklear indicates that the head of Fowler Industries was also the head of Capehart and Clavier Corporation. Fowler built the last few R-390A/URR receivers manufactured and delivered them to Avondale shipyards in 1984. Fowler also reportedly built R-390A spare subassemblies. The pursuit of these "Last of Breed" receivers has at times been the subject of much coversation on the R-390 mailing list. Tom Marcotte provided a copy of the letter that Fowler wrote to the DoD in 1990 announcing their sale to the Cardwell Condenser Corporation.
This tag turned up on a R-390A in Germany. Notice no manufacturer's name is given.
Les Locklear reported that Helena Rubinstein, the cosmetic maker, tried to diversify into electronics in 1960, and bid for the manufacture of a small lot of R-390A receivers. When they discovered the high cost of setting up a production facility, they allegedly purchased Collins units at a premium, relabeled them, and delivered them to the Navy. No Helena-Rubenstein receivers have ever surfaced in surplus stocks. There is no evidence that Helena-Rubinstein ever made another bid for the manufacture of R-390A receivers. Supporting letter
Tom Norris reports that his 1963 Imperial R390A has subassemblies marked "Teledyne-Imperial" while some parts are just marked "Teledyne" -- all with the same contract number. Imperial made about 3,000 receivers at the Panama Street location in Culver City (by Los Angeles) where Amelco started.
Manson Labs modified R-390A receivers into the R-1274 variant that NASA used in the Apollo space program.

Collins set up Motorola as a direct subcontractor for R-390/URR and R-391/URR radios to guarantee delivery of production quantities. Motorola also manufactured R-390A receivers from 1954 to 1958.
Servo Industries manufactured IF Subassemblies for the R-725 variant of the R-390A used by the military for direction finding work. Servo is still in business in Hicksville, NY, making modern direction finders for the marine and aeronautical markets.

If you know information about the Stewart-Warner R-390's, share them! Send mail to the FAQ-Meister!!!
Teledyne manufactured radios for the 1962 contract for which Amelco also produced radios (35064-PC-62). Teledyne reportedly made R-390A subassemblies at their Marina del Ray, California plant in the early 1970's. Subassemblies with only the Teledyne name and with "Imperial/Teledyne" have been found. Imperial radios contain Teledyne subassemblies that share the same contract number.
The R-1981 was a R-390A modified to bring out the 17 MHz, HFO and VFO signals to the rear panel and to insert an error correction signal for high-stability operation. It was a part of the TSC-25 communications system. The modifications were done using a kit of parts from The Technical Material Corporation (TMC) under contract number 14385-PC-58. The manufacturer of the R-1981 receiver is unknown. If anyone posesses one or knows of its history, send mail to the FAQ-Meister so we can share the information.
Tom Marcotte, N5OFF, manufactures reproduction ID tags for R390A receivers. Often, receivers are missing the tags, and these 'repro' tags take their place - as on my 1967 EAC from the St Julien's Creek collection.


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Version: 18 - - Last revision: 2022-May-31