On 3 Mar 2006 14:57:52 -0800, "purple_stars"
wrote:

i know everyone uses gps. enough said.

but i also know that a lot of cruisers (most ? all ? all of the smart
ones ?!) use alternate methods of finding their position and navigating
to both keep their skills current in case of emergency, to double check
the gps equipment, etc, etc. some use celestial navigation, everyone
uses piloting skills, and on and on.

but do you still use RDF ?

if so, could you talk a little about what equipment you keep on board
for it ?

most of the RDF equipment i've seen looks really old!


As your question didn't pull any responses, I'll chew the rag, for
what it's worth.
There are at least four DF systems in use.
1) VHFDF
2) UHFDF
3) Switched antenna radio
4) movable directional antenna radio.

1) & 2) have only seen much use around planes. They are line of sight
aids. In the air, that's ok, hunkered down on the briney, not so
helpful.

3) Hams have built and used circular antenna arrays to provide a
rotating directional sweep.

4) Commercial radios with a top rotating ferrite antenna and a compass
rose. Panasonic made a portable 6 band of this kind - I have one in
the bathroom.

Not sure if radios in cat 4) are still available, but they would be a
natural low cost choice.

Brian Whatcott Altus OK
p.s. GPS made a lot of aids obsolete, right there.