Take a look in your local library for a copy of the Radio Amateur's
Handbook. You'll find a discussion there on building small loop antennas
that can be pretty effective in RDF work.

Another option is to check Ebay from time to time for used RDF gear.
Heathkit made a lot of marine RDF units over the years and these are
usually priced reasonably.

Good luck!

Chuck

purple_stars wrote:


i'm going to try it.

i'm just going to get some of this RDF equipment and try it out on land
while using my handheld GPS and some maps to check against. or maybe
in the truck, i have an icom radio in the truck i can use with an
antenna, it has a strength meter built into it. i'll have to find a
good directional antenna to use, or make one. i'm going to check
around for some of the actual RDF equipment used in marine navigation
too though, i bet there is tons of this stuff in people's garages just
waiting for someone to find. when i was reading it looks like you can
also find old RDF/ADF equipment out of old airplanes too to play with,
and these have needles that turn to whatever transmitter is using the
frequency you tune too! fun stuff.

On Mon, 06 Mar 2006 01:57:32 GMT, chuck wrote:

Heathkit made a lot of marine RDF units over the years and these are
usually priced reasonably.

Good grief, they should be free.

Wayne.B wrote:
On Mon, 06 Mar 2006 01:57:32 GMT, chuck wrote:

Heathkit made a lot of marine RDF units over the years and these are
usually priced reasonably.

Good grief, they should be free.

Quite right, but where would you find the tubes?

"Bob" wrote in news:1142065241.058975.105470
@i40g2000cwc.googlegroups.com:

where would you find the tubes?


http://www.tubesandmore.com/

Stay away from Ruby tubes from China....They suck. Russian tubes are the
best!

Russia still builds tubes because tubes survive the EMP of an atomic blast.
The scary part is there are people in all government bureaucracies,
including mine, that worry about electronics surviving.

I sold 4 tubes just this week! Old Hammond organs are all tubes...(c;

chuck wrote:
Take a look in your local library for a copy of the Radio Amateur's
Handbook. You'll find a discussion there on building small loop antennas
that can be pretty effective in RDF work.

Another option is to check Ebay from time to time for used RDF gear.
Heathkit made a lot of marine RDF units over the years and these are
usually priced reasonably.

thanks chuck, sounds good.

i tried this evening to tune my icom ic-706-mkiig to listen to an NDB
(non directional beacon) at the local airport, failure! i couldn't
figure out why it didn't work either, i was within about 6 miles of one
of the transmitters and that transmitter was listed as being 25 watts,
so i should have had no trouble picking it up even with the crappy whip
antenna i had. but i couldn't hear a thing out of it, just static.
turns out that my icom radio is pretty much deaf as a post below about
300khz, and these transmitters were down in the 200-250khz range. oh
well, i guess i'll just get one of those marine RDF units and be done
with it lol, they can certainly tune to an NDB and listen to it. i
guess hearing it on my icom radio wouldn't have been a big
accomplishment anyway even if it had worked ... except that i could use
the opportunity to listen to the slow speed morse code, i'm still
learning CW/morse and haven't been practicing!

Your 706 is probably OK. The problem is that the whip's impedance is a
really poor match to 50 ohms at those long wavelengths. The marine VLF
radios use either an active antenna that performs the impedance
transformation or a special ferrite matching coil.

Try using a long metal fence or something similar and see if that makes
a difference.

Chuck


purple_stars wrote:
chuck wrote:

Take a look in your local library for a copy of the Radio Amateur's
Handbook. You'll find a discussion there on building small loop antennas
that can be pretty effective in RDF work.

Another option is to check Ebay from time to time for used RDF gear.
Heathkit made a lot of marine RDF units over the years and these are
usually priced reasonably.


thanks chuck, sounds good.

i tried this evening to tune my icom ic-706-mkiig to listen to an NDB
(non directional beacon) at the local airport, failure! i couldn't
figure out why it didn't work either, i was within about 6 miles of one
of the transmitters and that transmitter was listed as being 25 watts,
so i should have had no trouble picking it up even with the crappy whip
antenna i had. but i couldn't hear a thing out of it, just static.
turns out that my icom radio is pretty much deaf as a post below about
300khz, and these transmitters were down in the 200-250khz range. oh
well, i guess i'll just get one of those marine RDF units and be done
with it lol, they can certainly tune to an NDB and listen to it. i
guess hearing it on my icom radio wouldn't have been a big
accomplishment anyway even if it had worked ... except that i could use
the opportunity to listen to the slow speed morse code, i'm still
learning CW/morse and haven't been practicing!

On 6 Mar 2006 01:57:10 -0800, "purple_stars"
wrote:

except that i could use
the opportunity to listen to the slow speed morse code, i'm still
learning CW/morse and haven't been practicing!

Are you familiar with the W1AW code practice sessions? You should
have no trouble picking them up on your ICOM.

http://www.arrl.org/w1aw.html#w1awsked