US Navy Shipboard HF/MF/LF Transmitters
AN/SRT-xx, AN/URT-xx, AN/WRT-xx

Shipboard HF Transceivers

VHF and UHF Transmitters and Transceivers

WW2 Transmitters and Transceivers

Equipment Photo Specs Additional Info

Circuit Mayflower

The Circuit Mayflower (Shipboard) System is installed on a variety of U.S. Navy ships to provide a one-way-ship-to-shore HF radio link. It consists of an AN/BRT-2 system which has a KY-766A Keyer, TS-3858 silent tuner, modified AN/URT-23, AN/UGC-136CX teleprinter, and AN/USM-488 oscilloscope. The teleprinter is used to control the Keyer and to input various strings of coded messages from a classified codebook. The modification of the existing KY-766/BRT-2 Keyer to the KY-766A/BRT-2 configuration, which began in September 1991, will be completed in FY96. This change modified the existing punched tape reader and associated electronics of the KY-766/BRT-2 and replaced it with a direct electrical interface from the AN/UGC-136CX teleprinter via the SA-2626/BR and black switch board. 

Possibly related to use of AN/WRA-3 and AN/WRT-4?


bull-agmr1-01.JPG (218889 bytes) 10 KW HF shore station SSB xmtr used aboard communication and command ships and a few others --


WB6ZBX's restored SRT-14
srt14-99.jpg (45398 bytes)
100w LF/HF xmtr
synthesized VFO
4-400 final AM/CW/FSK
manuf by Federal
similar to AN/URT-2

includes -
  TN-229/SRT antenna tuner
  CU-372/SRT antenna coupler
  CU-402/SRT load adjusting unit

srt15-01.jpg (31055 bytes)


Download Manual

article in Electric Radio magazine April 1997 p4


3-01.jpg (106618 bytes) LF/HF xmtr
100w 300kc-2mc
500w 2mc-26mc
synthesized VFO
4-400 final AM/CW/FSK
manuf by Federal
similar to AN/URT-3

SRT-14 plus "booster"
(high-power modulator and 3000v power supply)


Download Manual



srt16-sys-01.JPG (1313681 bytes)  two SRT-14 plus one "booster"

LF/HF dual xmtr
100w 300kc-2mc
500w 2mc-26mc
synthesized VFO
4-400 final AM/CW/FSK
manuf by Federal
similar to AN/URT-4


Download Manual



prototype - what is it? manuf by RCA 1959 NAVSHIPS 92944


prototype - what is it? Manuf by ?
Amplifier design modified by Advanced Technology Corp 1960


urt3-101.jpg (262325 bytes)

Photos - Accessory Units

primarily shipboard use
100w 300kc-26mc
(URT-3, -4 also 500w 2mc-26mc)
4-400 final AM/CW/FSK
10 channel remote select 
(preset frequencies + automatic tuning)

Essentially an auto-tune version of SRT-14, 15, 16 - design predates SRT-14 series

OA-353 Transmitter assembly
C-916/URT remote control

Auto antenna tuner
OA-297/URT controller group +
CB-5/URT capacitor tuning unit +
TN-197/URT inductor tuning unit

Optional "booster" OA-354/URT
(3kv p/s + pair 4-125 modulator)

URT-2 is 100 watts
URT-3 is 500 watts with booster
URT-4 is two URT-2 + booster



design & manuf by Federal - see 
"An automatic tuning communication transmitter" - Dettman, M.
IRE International Convention Record
Volume 1, Issue , Mar 1953 Page(s): 137 - 144
An essentially identical article is here beginning on page 271. An additional article on the automatic tuning system begins on page 279

Additional information

My URT-3 restoration project

Coast Guard only?

urt12-01.JPG (203740 bytes)

more photos

75w HF 2-30 mc AM/CW
pair  4-65's modulated by 4-65's

manuf by Radiomarine 

urt12-02.JPG (91760 bytes)
photos thanks to Sam KF4TXQ

AN/URT-23 Transmitter

AN/URT-23C aboard USS Iowa
DSC02101.JPG (4375313 bytes)

DSC02103.JPG (4153318 bytes)

modern HF SSB transmitter
urt23-31.JPG (99345 bytes)

manuf by Harris

Photos and Info

Mil Spec MIL-T-28706F

12/69 manual download

6/79 manual download

urt23-01.JPG (30181 bytes)

T-827/URT - exciter
AM-3924/URT - RF amplifier
PP-3916/UR - power supply
MT-4670/URT-23 - shock mount
used with
   AN/URA-38 - antenna coupler group
       C-3698/URA-38 - controller
       CU-938/URA-38 - coupler

From CNO to CINCPAC 11/68
"The necessity for replacing the AN/SRT series transmitters with high reliability equipment... is a matter of vital interest. The AN/URT-23 will be available beginning in fiscal year 1970 for installation in the active fleet."


T-827B/URT exciter
t827-urt-1301-01.JPG (184932 bytes)

t827-urt-1301-04.JPG (151019 bytes)

t827-urt-1301-02.JPG (245030 bytes) t827-urt-1301-03.JPG (280222 bytes) t827-urt-1301-05.JPG (143139 bytes)
ET A School HF Transmitter/Receiver Sub-Systems (1982)
  - covers AN/WRC-1B and AN/URT-23(V)
Vol 3 part 1 - exercises - download pdf
Vol 3 part 2 - diagrams - download pdf

AN/URT-23E transmitter

T-827K/URT exciter
t827k-urt-1309-01.JPG (33355 bytes)

t827k-urt-1309-03.jpg (47492 bytes) AM-3924E/URT amplifier
am3924e-urt-1309-01.jpg (56367 bytes)
am3924e-urt-1309-05.jpg (110534 bytes)

AN/URT-24 Transmitter

need photo

T-827/URT exciter + AM-3007/URT amplifier

100w output 2-30mc

T-827B/URT exciter
t827-urt-1301-01.JPG (184932 bytes)
urc35-120310.JPG (39279 bytes)

AN/WRA-3 HF exciter
wra3-11.JPG (2709757 bytes)

CW exciter for use with AN/URC-32
0.5w or 15w output

Spec sheet

o1115-urc-101.jpg (3852120 bytes)

wra3-13.JPG (1845425 bytes)

CY-3022/WRA-3 cabinet
O-1115/URC synthesizer
AM-2819/WRA-3 amplifier
PP-2796/URA-3 power supply

REFERENCE: Final Report on Project 0/S66 FY63 - "Conduct an Evaluation of the AN/WRA-3 Radio Transmitter" 
11 April 1963, SECRET

wra3-14.JPG (1877600 bytes)

wra3-01.jpg (4142801 bytes)

LF Transmitter

wrt1a-31.JPG (125908 bytes) 300-1500 kc AM/CW/FSK
125w AM
500w CW/FSK
Download 64.9 MB pdf


2-30 mc transmitter
500W CW, FSK, AM
1000w SSB/ISB

Click here for more WRT-2 photos

- -

wrt2-1608-01.jpg (1082365 bytes) wrt2-101.jpg (124672 bytes)

AN/WRT-4 Transmitter

1 KW, water-cooled, CW transmitter

wrt4-01.JPG (352106 bytes)

Primarily for submarine use

Spec sheets

-- Need more info

Collins KWS-1 Transmitter

photos thanks to K7DFWKWS-1-NAVY-05.jpg (121142 bytes)

Collins KWS-1 SSB transmitter (modified)

KWS-1-NAVY-01.jpg (155575 bytes)

procured in 1956 along with modified 75A-4 for SSB experiments - KWS-1 was modified to cover Navy frequencies.

KWS-1-NAVY-02.jpg (203071 bytes)

Manual - NAVSHIPS 92787
Standard version
3.0 - 4.0 mc
7.0 - 8.0 mc
14.0 - 15.0 mc
21.0 - 22.0 mc
26.4 - 27.4 mc
28.0 - 29.0 mc
29.0 - 30.0 mc
Navy version
3.0 - 4.0 mc
4.0 - 5.0 mc
5.0 - 6.0 mc
7.0 - 8.0 mc
13.0 - 14.0 mc
14.0 - 15.0 mc
KWS-1-NAVY-04.jpg (145776 bytes) KWS-1-NAVY-03.jpg (142062 bytes) Standard KWS-1 info page