The R-390A militaryshortwave radio receiver was the result of a project undertaken by the United States Army Signal Corps in 1954 to replace the existing R-390 receiver then in use. The R-390 had done its job so well that the Corps decided continued use of this type of receiver necessitated an improved, reduced-cost version. There are many references to the R390A in the open literature during this period; a picture of the receiver appeared in the May 1959 issue of QST.[1]
The total production of the R-390A (as determined by the high serial numbers noted) is over 55,000 units. Initial production started in 1955 and ran through approximately 1970, and then was restarted in 1984 by Fowler Industries for Avondale Shipyards. Manufacturers and their approximate production numbers are:[1]
Companies which made spare modules, but not whole sets were Communications Systems Corp., Clavier Corp. and Hacking Labs.
Design
The R-390A is a general coverage radio receiver capable of receiving amplitude modulated, code, and frequency shift keying signals. Its tuning range is from 500kHz to 32MHz, in thirty-two 1MHz bands. The circuit is the superheterodyne type, double conversion above 8MHz, below which triple conversion is used. It employs 23 vacuum tubes, a larger than normal count for most general-coverage receivers.
The receiver weighs 85 pounds (39 kg) and can be operated on 120-volt or 240-volt supplies. It fits neatly into a 10.5-inch-tall (270 mm) standard 19-inch rack.[2]: 6 [3] Tuning of the R-390A's radio frequency and intermediate frequency front end is synchronized by means of an ingenious mechanical system of racks, gears, and cams. When the front panel tuning controls are rotated, this system raises and lowers ferrite slugs in and out of the receiver's tuning coils. This ensures that all front-end circuits are tracked, meaning all circuits are tuned to the correct frequency to maintain excellent selectivity and sensitivity. The receiver's construction is modular for easy servicing. Each major area of the receiver is contained in easily removable subassemblies, and these can be repaired or replaced as needs be. Though the R-390A is mechanically and electrically complex, alignment and servicing were designed to follow simplified procedures published by the Signal Corps.[2]
Use
The R-390A was deployed to most branches of the US military and remained in general use through the 1980s. The last major update to its documentation was in 1984. As the military procured newer receivers, many R-390As were released to surplus while others were destroyed. Some receivers were retained by the services, however, when they found that the R-390A's vacuum tube circuitry could easily survive an electromagnetic pulse. There are reports, possibly apocryphal, that R-390A receivers are still in use aboard U.S. Navysubmarines since the receiver can withstand the strong radio frequency fields found aboard ship.[1]
Many of the R-390As that exist today are in the hands of vintage amateur radio collectors and amateur radio operators who contend that few modern solid state communications receivers can equal its performance. There is a wealth of information, both printed and electronic, devoted to R-390A restoration and maintenance, as the R-390A is widely considered an example of the best of vacuum tube technology.[1]
^ abcdRippel, Chuck (24 December 2001). . The R390A/URR. Archived from the original on 27 September 2007. Retrieved 10 December 2022.
^ abTM 11-5820-358-10 — Operator's Manual: Radio Receiver R-390A/URR (4 ed.). Headquarters, Department of the Army. 7 April 1975 [16 January 1961]. p. 3. Retrieved 10 December 2022 – via Google Books.
^TM-11-5820-358-35 — Field and Depot Maintenance Manual: Radio Receiver R-390A/URR (3 ed.). Headquarters, Department of the Army. 27 May 1980 [8 January 1961]. Retrieved 10 December 2022 – via Google Books.
Further reading
Couillard, L. W. (15 January 1952). Cost Reduction Program For Radio Receivers, R-390/391( )/URR | Final Progress Report(PDF) (Technical report). Cedar Rapids, Iowa: Research And Development Laboratories | Collins Radio Company. (PDF) from the original on 17 July 2022. Retrieved 12 December 2022 – via r-390a.net.
External links
"Receiver Test Data | Collins R-390A". Sherwood Engineering Incorporated. Denver, Colorado. 23 October 2018. from the original on 4 December 2022. Retrieved 12 December 2022.
February 17, 2023
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The R 390A URR is a general coverage HF radio communications receiver designed by Collins Radio Company for the United States Armed Forces R 390A radio receiver Contents 1 History 2 Design 3 Use 4 See also 5 References 6 Further reading 7 External linksHistory EditThe R 390A military shortwave radio receiver was the result of a project undertaken by the United States Army Signal Corps in 1954 to replace the existing R 390 receiver then in use The R 390 had done its job so well that the Corps decided continued use of this type of receiver necessitated an improved reduced cost version There are many references to the R390A in the open literature during this period a picture of the receiver appeared in the May 1959 issue of QST 1 The total production of the R 390A as determined by the high serial numbers noted is over 55 000 units Initial production started in 1955 and ran through approximately 1970 and then was restarted in 1984 by Fowler Industries for Avondale Shipyards Manufacturers and their approximate production numbers are 1 Units produced Manufacturer Approximate production numbers NotesCollins Radio Company 6 363Electronic Assistance Corp 15 338 Includes Dittmore Freimuth marked radiosCapehart 4 242Motorola 14 873Stewart Warner 6 631Amelco Teledyne Imperial 7 958 These companies were related through acquisitionsFowler Industries 5Companies which made spare modules but not whole sets were Communications Systems Corp Clavier Corp and Hacking Labs Design EditThe R 390A is a general coverage radio receiver capable of receiving amplitude modulated code and frequency shift keying signals Its tuning range is from 500 kHz to 32 MHz in thirty two 1 MHz bands The circuit is the superheterodyne type double conversion above 8 MHz below which triple conversion is used It employs 23 vacuum tubes a larger than normal count for most general coverage receivers Units produced Quantity Part number Type3 6AK6 Pentode2 5654 Pentode4 12AU7 5814A Triode2 26Z5W Full Wave Vacuum Rectifier1 3TF7 Current Regulator6 6BA6 5749W Pentode3 6C4 6100 Triode Medium m 1 6DC6 Pentode1 0A2WA Voltage RegulatorThe receiver weighs 85 pounds 39 kg and can be operated on 120 volt or 240 volt supplies It fits neatly into a 10 5 inch tall 270 mm standard 19 inch rack 2 6 3 Tuning of the R 390A s radio frequency and intermediate frequency front end is synchronized by means of an ingenious mechanical system of racks gears and cams When the front panel tuning controls are rotated this system raises and lowers ferrite slugs in and out of the receiver s tuning coils This ensures that all front end circuits are tracked meaning all circuits are tuned to the correct frequency to maintain excellent selectivity and sensitivity The receiver s construction is modular for easy servicing Each major area of the receiver is contained in easily removable subassemblies and these can be repaired or replaced as needs be Though the R 390A is mechanically and electrically complex alignment and servicing were designed to follow simplified procedures published by the Signal Corps 2 Use EditThe R 390A was deployed to most branches of the US military and remained in general use through the 1980s The last major update to its documentation was in 1984 As the military procured newer receivers many R 390As were released to surplus while others were destroyed Some receivers were retained by the services however when they found that the R 390A s vacuum tube circuitry could easily survive an electromagnetic pulse There are reports possibly apocryphal that R 390A receivers are still in use aboard U S Navy submarines since the receiver can withstand the strong radio frequency fields found aboard ship 1 Many of the R 390As that exist today are in the hands of vintage amateur radio collectors and amateur radio operators who contend that few modern solid state communications receivers can equal its performance There is a wealth of information both printed and electronic devoted to R 390A restoration and maintenance as the R 390A is widely considered an example of the best of vacuum tube technology 1 See also EditART 13 transmitter ARC 5 BC 348 BC 654 Collins Radio Hammarlund super pro National HRO Vintage amateur radio 75A 4 and KWS 1References Edit a b c d Rippel Chuck 24 December 2001 The R390A home on the WWW The R390A URR Archived from the original on 27 September 2007 Retrieved 10 December 2022 a b TM 11 5820 358 10 Operator s Manual Radio Receiver R 390A URR 4 ed Headquarters Department of the Army 7 April 1975 16 January 1961 p 3 Retrieved 10 December 2022 via Google Books TM 11 5820 358 35 Field and Depot Maintenance Manual Radio Receiver R 390A URR 3 ed Headquarters Department of the Army 27 May 1980 8 January 1961 Retrieved 10 December 2022 via Google Books Further reading EditCouillard L W 15 January 1952 Cost Reduction Program For Radio Receivers R 390 391 URR Final Progress Report PDF Technical report Cedar Rapids Iowa Research And Development Laboratories Collins Radio Company Archived PDF from the original on 17 July 2022 Retrieved 12 December 2022 via r 390a net External links Edit Receiver Test Data Collins R 390A Sherwood Engineering Incorporated Denver Colorado 23 October 2018 Archived from the original on 4 December 2022 Retrieved 12 December 2022 Retrieved from https en wikipedia org w index php title R 390A amp oldid 1134816433, wikipedia, wiki, book, books, library,
