[Milsurplus] See photos. Were modified SCR 269 ADFs used on USCG boats to DF sigs in 2-3 MHz marine band?

[Boeing377]

I grew up in commercial fishing, my Dad's trade. In the 1960s I saw several very professionally modified SCR 269 installations on commercial fishing boats. Band 3 in the BC 433 rcvr was modified to cover 2-3 MHz and the dial for the control box was professionally modified to reflect the new band markings. It almost looked stock, very close. A high class mil surplus conversion indeed.

I did a similar modification to an ARN 7 by tweaking the band 4 osc coil but was unable to come up with a new dial so I just put markings on the old band 4 dial for 2182, 2638, 2738 KHz and other marine channels. It was a crackerjack marine band ADF and outperformed the commercial ones made by Raytheon and others in the 1960s. The professionally modified SCR 269 sets got rave reviews for their accuracy and sensitivity too. Thye bearing compensator in the LP 21 loop had no equal in the commercial sets and the extensive rigging on fishing boats distorted bearings. You could dial out the bearing distortion with the LP 21 compensator and get spot on bearings.

Jack Antonio generously gave me one of the BC 433 control heads I had seen as a kid with band 3 marked 2-3 MHz on the band switch and a suitably modified tuning dial. It was just as I had recalled, almost looked stock. Beautifully done. 

Recently I  came across some photos (circa 1961) showing USCG boats with LP 21 football loops. Could they have been using WW 2 SCR 269 Radio Compass sets modified to take bearing on the 2-3 MHz marine band? Might these have been made under a govt contract?

See here: https://sites.google.com/site/scr269onuscgvessels/

It would have made no sense for USCG boats to use stock SCR 269 stes for beacon and BC band DFing as numerous sets covered these bands already. In 1960s SAR work 2-3 MHz marine band DFing would have been extremely valuable. 

73
Mark
AF6IM
www.parachutemobile.com