NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Radio direction-finders
From: George Huxtable
Date: 2009 Dec 9, 22:54 -0000
From: George Huxtable
Date: 2009 Dec 9, 22:54 -0000
Joe Schulz wrote- "Question for George: is navigation RDF still in use in Europe? I'm talking about the LW frequencies (under 530kHz). Over here it's dead as of next year; the fishermen's politicians couldn't keep it going." No, they went years ago. Many of the marine radio direction-finding transmitters were converted to broadcast differential corrections for GPS, in the days when that was made necessary by the dreadful euphemism "selective availability". There may be a few aero radio beacons remaining. The marine beacons commonly shared a frequency, in a group of 5, each one being allocated one minute of a 5-minute sequence. When you tuned in, the one you were specially interested in had always just happened. And then, when it came around again, by the time you had worked out the Morse call-sign and swung the antenna for a null, it was all over. It was necessary to be quick. In my days of navigating a small boat in the strong tides around the coasts of Southern England, Normandy, and Brittany, without GPS or Decca, the RDF stations were a Godsend. They were especially useful when placed near a harbour entrance, so you could home in on them. Cross-bearings were never very accurate, but provided a bit of reassurance. Mostly, I would be working by dead-reckoning. In my early sailing days, there would also be Consol, a left-over wartime aid, in which one transmitter produced dots, and the other dashes, interleaved. There was no need to swing an antenna for a null; you had to count the blips in a sequence until they merged into a steady tone. I never got-on very well with Consol. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com