Navy HF Diversity Receiving Systems

Diversity systems use 2 or 3 receivers to copy the same traffic (typically CW or RTTY) from one or more transmitters
Frequency diversity - receivers tuned to different frequencies - to cover shifting ionospheric propagation
Spatial diversity - receivers tuned to the same frequency but connected to different antennas - to cover fading and multipath

Back to Main Receiver Page
Back to main Navy Radio Page
Please send me e-mail if you have any additions, corrections, etc.
Many of these photos are of equipment that was for sale on eBay.
Go here for RECEIVER MANUALS

HF Diversity Receiver Systems
model	type	primary use	freq	features
AN/FRR-3 AN/FRR-3A		Dual Diversity 2.4-23 mc HF Shore FSK Remote dial-up to select 5 fixed frequencies and 4 antenna combinations		manuf Press Wireless TM 11-872 Manual extract
AN/FRR-3 AN/FRR-3A				manuf Press Wireless TM 11-872 Manual extract
AN/FRR-10		Dual Diversity HF shore SSB (simultaneous USB & LSB) variant of FRR-24 click here for info	2-32 mc	dual diversity 253 tubes Manuf National info
AN/FRR-24		Triple Diversity HF shore RTTY & CW click here for info	2-32 mc	triple diversity 420 tubes Manuf National info/photos
AN/FRR-28 0.54-54 mc Dual Diversity - HF shore	two R-450/FRR-28 rcvrs O-165/UR master oscillator AM-615/UR amplifier/detector KY-79/UR keyer SB-224/UR patching panel LS-187/UR speaker	R-450/FRR-28 showing AVC switch and ID tags	uses two Hammarlund SP-600-MX (R-450/FRR-28) used with AN/URA-8A RTTY converter info SP-600 manuals FRR-28 spec sheet - page 1 FRR-28 spec sheet - page 2 FRR-28 at NAVCOMMSTA Kodiak 1959	More R-450/FRR-28 photos Manual - NAVSHIPS 91582 manuf - Northern Radio
AN/FRR-32			Dual Diversity - HF shore system 2-32mc two R-618/FRR-32 rcvrs (probably modified FRR-23) O-330/FRR-32 master xtal oscillator CM-70/FRR-32 comparator/keyer SB-431/FRR-32 patching panel LS-169/G speaker CY-597A/G rack	Manuf RCA NAVSHIPS 92736 manual pdf
AN/FRR-37		Dual Diversity version of FRR-24 HF shore RTTY & CW Click here for component info	2-32 mc	dual diversity approx 250 tubes Manuf National info/photos
AN/FRR-38		Dual Diversity FSK two R-390(*) receivers CV-116/URR dual FSK converter	0.5-32 mc FRR-38 and FRR-41 at NAVRADSTA ( R) Salinas	Signal Corps procurement but used by USN Manuf Collins & Hoffman TM-11-647 TO: 31R2-2FRR38, 31R-1-8
AN/FRR-41		Dual diversity SSB two R-390(*) receivers two CV-157 SSB converters (simultaneous USB & LSB from each)	0.5-32 mc FRR-38 and FRR-41 at NAVRADSTA (R) Salinas	Signal Corps procurement but used by USN Manuf Collins & others TM 11-649 TO: 31R2-2FRR-221
AN/FRR-42 AN/FRR-43	Subset of AN/FRR-24	Click Here for Info	-	-
AN/FRR-51	need photo	Dual-diversity HF with 10 channel auto-tune R-792/URR receiver (2 ea.) CU-560/URR antenna coupler C-2087/URR receiver control C-2086/URR remote switching control CV-116/URR FSK converter CV-395/U Signal Data Converter CY-1119/U cabinet	need info	need info - please send e-mail
AN/FRR-55	AN/FRR-55 was the Receiving Set portion of the AN/FRC-63 UHF Moon Bounce System
AN/FRR-55
AN/FRR-60(V)	photo from TMC vintage radio web site	HF shore diversity system NAVCOMMSTA Guam - 1960's	More Info - AN/FRR-60 Page	Manuf TMC Model DDR-5
AN/FRR-74		TMC-DDR-5K Similar to FRR-60 but with 4 ISB	spec sheet	--
AN/FRR-85		TMC DDRR-10 w/ remote tuning	spec sheet manual download	-
AN/URR-49	Guam 1968 - URR-49 configurations	HF shipboard/shore FSK dual-diversity system two R-390A receivers AN/URA-8A dual FSK converter	info needed	Nomenclature was assigned and this configuration was widely used both afloat and ashore, but I'm not sure it was ever procured as AN/URR-49
AN/URR-63	need to add photos	TMC DDRR-10 w/ remote tuning	manual download	-
AN/URR-64(V)	AN/URR-64(V)1 dual diversity (two receivers with two synthesizers)	AN/URR-64(V)2 single receiver More URR-64 Photos	AN/URR-64(V)3 dual space diversity (two receivers with one synthesizer	TMC model DDR-10 - photos thanks to www.tmchistory.org manual download Components TN-512/URR tuner TD-915/URR demultiplexer O-1511/URR freq synthesizer --
RAE	Pre-war triple-diversity HF unit using three RAB receivers	See RAB photos and info on WW2 Receiver Page	-	-
RBP RBP-1 RCP			1940's system 3-24 mc RBP is dual triple-diversity system (6 rcvrs) RCP is single triple-diversity system (3 rcvrs)	Manuf RCA RBP & RCP Page - spec sheets, photos, and downloadable manual
RDM (RCA DR-89)	Triple Diversity HF System using RCA AR-88 receivers		CRV-46246-A (RCA-AR-88F) as used in RDM	CRV-46246-B (RCA CR-88) as used in RDM-1 Manual NAVSHIPS 91061 Download 28.9 MB pdf
				1945 photo
		CRV-46246-A (RCA-AR-88F) as used in RDM		1945 photo



				==
	Tone Keyer for RDM


				==
Crosby SSB Diversity Receiver	Info and Photos from NAVSHIPS 93224 - not known if a mil-spec version was fielded