Navy Shore Station LF & VLF Transmitters

Also see  Naval Shore Electronics Criteria: VLF, LF, and MF Communication Systems - NAVELEX 0101,113

Telefunken 500 kw Rotary Generator
yosami-01.JPG (26146 bytes)		 500 kw, 17.442 kc

Great photos here and here

Schematic diagram here

 installed 1929 at Yosami Japan
USN use 1950-93

replaced by AN/FRT-64?
need more info about this

yosami-02.JPG (207887 bytes)
AN/FRT-3
frt3-110301.JPG (46281 bytes)		 1400 kw VLF 24.8kc - RTTY & CW
frt-3-jimcreek-01.jpg (27351 bytes)		 installed at NLK Jim Creek WA

manuf RCA 

Jim Creek Station Page with photo articles on transmitter and antennas

 jimcreek-ant-01.JPG (54673 bytes)
 

AN/FRT-4
frt4-110301.JPG (83291 bytes)

 AN/FRT-4 transmitter (54722 bytes) 55 kw LF 50-150 kc
similar to TCG-2 except air-cooled

AN/FRT-4 transmitter (266781 bytes)

 spec sheet

manuf General Electric

NAVSHIPS 91169
AN/FRT-4 at Buskin Lake
buskin-schwind-06.jpg (165790 bytes)		 AN/FRT-4 at Buskin Lake
buskin-schwind-110307-02.jpg (333988 bytes)		 View from inside AN/FRT-4 -
looking out at AN/FRT-18
buskin-schwind-110307-05.jpg (265672 bytes)
AN/FRT-10

need photo

500 kw LF 100-200 kc CW/FSK -  spec sheet
dual 250 kw transmitters
diesel engines for p/s

installed at Guardamar, Spain

Info from John Cobb:
"The AN/FRT-10 was unique, a 500 kW LF giant tuning 100 - 200 kHz. It was in two amplifier bays, which we drove alternately with an external TMC synthesized exciter stack, running the single-channel KSUB broadcast at about 50 kW. It fed a 1200-foot tower, through 8-inch rigid coax and a big variometer/capacitor network in the helix house. The amplifier bays each  consisted of IPA and driver stages for the finals: four air-cooled 6697 triodes in grounded-grid push-pull configuration!"
AN/FRT-19
frt19-01.JPG (98817 bytes)		 frt19-110301.JPG (157325 bytes) 15 kw LF 30-300 kc CW/FSK
3 kw LF 300-600 kc CW/FSK

frt19-110302.JPG (157707 bytes)

Manual NAVSHIPS 92117

Manuf by Sierra Electronics

Used in AN/TSC-35 transportable COMMSTA - and elsewhere?
AN/FRT-31

More Cutler & FRT-31 photos and info

frt31-31.JPG (42775 bytes)

2MW VLF (17.8 / 24 kc) - 
four separate 500-kw final amplifiers, each with eight ML-6697 air-cooled tubes operating in push-pull parallel

naa-qst-3.JPG (215485 bytes)

 installed at NAA Cutler, ME 

frt31-61.JPG (60020 bytes)

 Manual NAVSHIPS 94356

Manuf by Continental Electronics

cost $2,530,814

More Cutler & FRT-31 photos and info

AN/FRT-61
frt61-61.JPG (87289 bytes)		 frt61-1103-01.JPG (95922 bytes)
AN/FRT-61 Helix House		 100 kw peak, 50 kw average
50-150 kc
CW / FSK

Used in AN/TSC-35 transportable COMMSTA - and elsewhere?

 Manual NAVSHIPS 94592

Manuf by Continental Electronics

cost $299,633.

AN/FRT-64
frt64-1103-01.JPG (199215 bytes)		 1MW VLF (21.4 / 23.4 kc)
FSK +/-25 cycles

frt-64-lululei-01.jpg (27236 bytes)


similar to AN/FRT-31 but with water-cooled finals

installed at NPM Lualualei, HI
(and Yosami Japan?)

Manuf by Continental Electronics
Manual NAVSHIPS 95884

Lualualei site photos

lua-ant-01.JPG (69346 bytes)
AN/FRT-67

frt-67-exmouth-01.jpg (25767 bytes)

frt67-1103-01.JPG (148530 bytes)
AN/FRT-67 Helix Room		 2MW VLF (19.8 / 22.3 kc)
Manuf by Continental Electronics

installed at NWC Harold E. Holt, Exmouth, Australia

 holt-ant-01.JPG (373350 bytes)
AN/FRT-72
AN/FRT-72A
AN/FRT-72 (63869 bytes)
Bouknadel 1970
(thanks to Darian Paganelli)		 AN/FRT-72 (180079 bytes) 100kw peak, 50 kw average
30-150kc

 		NAVSHIPS 0967-033-8000

manuf by Continental Electronics 

Note - FRT-72's from Driver, Grindavik, and Thurso were moved to Colorado for use at WWVB - photo here

Thurso helix house today - photo
AN/FRT-72B
bouk-pag-05.jpg (52425 bytes)
Bouknadel 1970
(thanks to Darian Paganelli)		 frt72b-1103-01.JPG (99466 bytes) 100kw peak, 50 kw average
30-150kc
frt72b-1103-02.JPG (85233 bytes) 		manuf by Continental Electronics 

 

AN/FRT-73
summit-js-04.JPG (1420084 bytes) 		installed at NBA Summit, Panama

summit-js-07.JPG (1190445 bytes)


Manuf by Continental Electronics
summit-js-05.JPG (1138304 bytes) 		summit-js-02.JPG (648264 bytes)
1 MW VLF water-cooled
summit-js-06.JPG (1162214 bytes) 		balboa-ant-01.JPG (67726 bytes) helix-house-01.JPG (52053 bytes)
AN/FRT-87

need photo

Click Here for photos and info

1 MW VLF

Manuf by Continental Electronics

 installed at NSS Annapolis, MD annapolis-ant-01.JPG (139074 bytes)
Info from Roy K1LKY "I was fortunate to visit the VLF station at NSS Annapolis before it was dismantled. On that trip we learned that the narrow shift FSK keying put the carrier alternately on either side of the center of the tuned system. It was some 10 percent down the slope (memory of the details are faint.) But the antenna current was monitored at the console and would vary depending on how far down the slope the tuning had shifted the center of the very narrow sweet spot. The operator could vary one of the inductors in the system by remote control to match the two currents. That system operated at 20.4 kc I believe, at an output power of about eight tenths of a megawatt. The shift may have been on the order of 10 to 15 CPS. The antenna was one mile long, about 800 to 1200 feet up, and was tuned with a massive inductor made of five inch diameter Litz wire. Cutler Maine still operates with similar parameters, as far as I know."
AN/FRT-95 need photo modern solid-state VLF
installed at Aguada, PR 		 -
TACAMO

24/7 Airborne 200kw VLF relay transmitter with 25,000 ft. trailing wire antenna

EC-130Q and E-6 aircraft

Info Page Here

And More Here

 tacamo-01.jpg (1232126 bytes) tacamo-02.jpg (222669 bytes)

tacamo-03.jpg (3128669 bytes)

radio equipment manuf by Collins - please send e-mail if you know the designation