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!

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

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

That's because it has been virtually obsolete for over 20 years, ever
since LORAN-C became widely available and affordable back in the early
'80s. Truth is, RDF was never all that accurate or reliable, it's
just that it was the only affordable electronic aide to navigation for
many years. I still have mine in the garage and I'm not expecting it
to move anytime soon. The best backup for GPS is another GPS, and
some spare batteries.

On Fri, 03 Mar 2006 23:11:04 -0500, Wayne.B
wrote:

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

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

That's because it has been virtually obsolete for over 20 years, ever
since LORAN-C became widely available and affordable back in the early
'80s. Truth is, RDF was never all that accurate or reliable, it's
just that it was the only affordable electronic aide to navigation for
many years. I still have mine in the garage and I'm not expecting it
to move anytime soon. The best backup for GPS is another GPS, and
some spare batteries.

I have an old RDF and have wondered if it could be useful for any
purpose. For example, getting a bearing on a VHF radio transmission
from a boat in distress. Or, perhaps, getting a bearing on an AM or
FM radio tower or a FAA tower. Any conceivable use for it or fun to
be had with it, or is it time to send it to Davy Jones?

Lee Huddleston
s/v Truelove

On Sat, 04 Mar 2006 06:00:41 GMT, (Lee
Huddleston) wrote:

Any conceivable use for it or fun to
be had with it, or is it time to send it to Davy Jones?

Think of it as an overgrown AM radio, but who listens to AM radio
anymore? I haven't used my RDF in the last 20 years, and haven't even
kept it on the boat for about that long.

RDF is not without use. It saved my life in a tropical storm (or at
least made the ride a lot better) by finding the strongest T-storms for
me so I could go the other way.

But then again, I use a sextant to measure clouds to see how fast they
are rising and in what direction they are traveling :-)

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!

I thought the transmitters were switched off years ago.

RDF is nice to have if it covers the MW band, but it is very very nice to
have if it covers the VHF band. This allows you to get a bearing on other
boats, not just shore stations.
Steve

"purple_stars" wrote in message
oups.com...
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!

You are right. Any AM radio station can be tracked.

That is all RDF ever did and contrary to what some others have said
here it is very accurate. I use RDF for instrument approaches in
airplanes regularly. The only reason it is not used much anymore is
because it fails to give other information that other equipment can
give these days, like VOR's that can give a bearing to/from as opposed
to just to and DME that is found on most VOR sites. None of that is
really mariner equipment but since aviation is what drove a lot of the
more modern equipment, it is important because it also killed the old
gears popularity.

I mentioned in another post that I tracked lightning with an RDF. The
pulse of electricity that comes from lightning makes the needle of the
RDF jump and point toward the source of the electricity (the lightning)
It is a really great tool should you get caught out in an area of
storms and need to know where the heaviest activity is.

I was out between Swan island, Honduras and Jamaica, right out in the
middle of nowhere, the first week of June one year and sailed right
through the first tropical storm of the year. The RDF I had lead me
away from the strong cells and really did save my life. As for why I
was there, I got stuck going through the Panama Canal and really didn't
have any other choice unless i wanted to spend the summer in Panama and
Colon Panama isn't fun for a day!

On that thought, if anyone has one of those that they want to sell, I
would like to buy it.

A couple of comments.

While opinions about accuracy vary, no numbers have been posted. Come
Spring, it would be great to see a couple of sailors with RDF's take
them out of hiding and check their accuracy against their GPS.

No RDF is going to provide a position within a few meters except by
accident. but most of us work really hard to avoid needing that kind of
accuracy.

Many portable AM radios (read cheap, garage sale variety) have ferrite
antennas that are often sufficiently directional to be usable for RDF
work. Rotate the whole radio and use with a crude hand-drawn scale. It
might even be fun to use one of these "lower tech" systems. Not quite as
accurate as optical triangulation, but at least as much fun. And then
there's the added bonus of an on-board source of weather, news, "music",
and talk shows!

Good luck!

Chuck

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!