[Milsurplus] Re: DF ing LO radiation

[BOEING377 at aol.com]

Dunno if it was done in WW 2, but I do know from real world marine DF experience that such a low power signal would not provide very good bearings at any significant distance. My dad's commercial fishing boat was the site of many surplus installations by his surplus crazy kid, me. Our ARN 7 ADF (a truly EXCELLENT ADF by the way, blew away the commercial competitors in sensitivity and accuracy) was in constant operation, my Dad believing that marine electronics should be left on all the time to combat moisture and corrosion. Late in the game the USCG started putting up low power (10 watt) LF beacons on numerous jetties and breakwaters. The Farallon Island beacon was reported to be 500 watts and could be "shot" from SF (27 miles away) with 100% reliability. We often could shoot it from the Mendocino coast, over 150 miles away. The low power jetty beacons were easlily received at a good distance with a long wire antenna, but when you switched to the loop and tried to shoot them, it was pretty rare to get reliable bearings more than a couple of miles away. I'd venture to say that in clear weather you could see a ship before you could DF any LO radiation. My late father in law spent WW 2 DFing German subs from a US navy station in Brazil. He saids they had several confirmed kills, acft directed to a site by their DF fixes (cross bearings from other DF stations) which then sunk a sub. They never looked for LO radiation, just HF comms. He laughed at the idea of DFing LO radiation at any distance. He said the German sub comms were normally very short and they had to be lucky and quick to get a DF shot. BTW, the term "shot" gained a lot of attention in a mysterious incident at sea (off California) between two commercial fishing boats (Coho II and the Steelhead) in the 60's. As I recall one boat made a quick radio call saying the other had "shot" him and then went missing. The "shooter", suspected of murder, claimed that the "shot" referred to was a DF shot, not a rifle shot.