[Milsurplus] Mobile VHF DF Set

[C.Whitaker]

de WB2CPN
Can anyone aim me at some info I need:
The van-mounted VHF DF set that had
a BC-639 receiver inside, and a four-element
vertical antenna on the top of the van.  The
antenna elements were arranged in a rectangle.
The operator had a wheel that was used to
rotate the antenna for a null.
The were two ambiguous nulls, 180 degrees
apart.
The operator had a switch mounted on the
antenna shaft.  This "sensing switch" removed
the false null.
I am looking for info on the antenna system, and
the sensing switch.
Maybe SCR-375 (?).
Robert, are you listening?
73  Clete
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