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Old February 18th 05, 05:02 PM
Irv Finkleman
 
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"M. J. Powell" wrote:

In message , Irv Finkleman
writes
RB wrote:

Brings back scenes from old WWII movies....


Small loops are still used and seem to be very effective for DF. I think that
the ARRL antenna book provides information in this direction. One system I
saw used a short ferrite dipole array.

In most cases, DF sets displayed their goniometer outputs on a CRT or as
signal strength on a meter. In this case, the dots and dashes melded into
a continous output because of the persistence of the CRT or the AGC delay
of the receiver.


I don't think there was a swinging goniometer with the CRT DF set. The
output of the two loop aerials fed the X and Y plates respectively so
that the trace appeared at the right angle and the bearing was read from
the screen.

Mike


There were a number of different types of DF sets. Some, as you
point out had x and y
plates connected to the loops, another had a mechanically rotating gonio.
We had one for radar detection which used horns with crystal detectors in
it which went to x and y plates (through amps). The HFDF used loops feeding
a mechanically rotating gonio with output to a crt.

Irv


--
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Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada