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!