Thanks John, but the ramsey units require huge antennas and to great a
spread between them. I have looked at them on several occassion, but can't
see how I could make them work.

Charlie
"UltraJohn" wrote in message
ink.net...
ccwillwerth wrote:

Hi All,

I am fitting my homebuilt with instruments and radios, and wanted to add
a
Direction Finder. I wanted a doppler type, but with small antennas in a
4
point aray with a small dimension or distance between the antennas. Am I
really far out of reason, or is this an achievable goal?

Charlie

Hi Charlie
There are many kits out there that will do this. Here is one.
http://www.ramseyelectronics.com/cgi...ction&key=DDF1
Of note is most require an FM receiver and aviation uses AM signals.
Although the transmitted signal doesn't need to be FM it can be SSB CW AM
or FM but it might be hard to get a receiver that will receive using FM on
the aviation band. Although if you can get schematics of your receiver you
should be able to modify it for FM reception (add a coax connection to one
of the many FM demodulators kits (I think this Ramsey company has one)
just
make sure they both use the same IF) I wouldn't try this with your active
aircraft receiver.
John