wrote:
This is a good article. I've often wondered about that ferrite with the
two windings on it.
http://user.netonecom.net/~swordman/...Loops_Fig9.jpg
That is how my RDF antenna is designed. If you look at many of the old
boating RDFs, they use a stereo phone plug/jack as the interface, i.e.
two wire ends plus ground. The ferrite sits in a copper shield.

Untuned loops really make sense if your radio is decent. That is one
reason I like the wellbrook. But this paper has given me a few ideas on
how to use a RDF loop. Incidentally, the ferrite rods from these RDFs
show up occasionally at flea markets. The radio has crapped out, but
someone wisely saved the ferrite. I saw one on sale for $2 at the last
Livermore swap meet.
++++++++++++++++++++++++++
By using Litz wire and taking some care it is "easy" to get a ~10" X
3/4"
rod to work up to around 10MHz. Above that it goes downhill "real
fast".

I ran into this winding on a dead RCA RDF a friend gave me. I rembered
seeing the article back in Radio Electronics but had completly
forgotten.

Burhans had some designs that were light years a head of their time!

I wish I had payed more attention when they first came out. It was a
royal
PITA to get photocpies from the local university's enginering library
microfilm
editions of Radio Electronics.

Terry