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