[Milsurplus] BC-938A, BC-616

[David Stinson]

----- Original Message ----- 
From: "Ken Kinderman" <scr274 at gmail.com>
Subject: [Milsurplus] BC-938A, BC-616


> Can anyone give some context for the BC-938A control box I found buried in
> the garage?...
>As to the BC-616, it is a relay box ...

The BC-938 is the TX control box for the ancestor of the AN/ARC-5 VHF set,
the SCR-274N VHF rig produced by W.E.  Only about 1000 were
produced and most were re-tooled into AN/ARC-5, along with
a new nomen plate (ARC-5 C-30) for the control box.
The set looked almost identical to the later, improved ARC-5 that
saw so much service.  The -274N VHF had an 815 P-P modulator
built into the transmitter, which was retro-fit out of the AN/ARC-5
version that went into large-scale production.  That's why early versions
of the VHF T-23 have a tube socket and two smaller,. plate-cap
feed-thru holes plugged on the front part of the chassis.
Some even have "815" marked next to them.
It is a scarce piece.  I'd trade well for it, if I didn't already have one.

The BC-616 is part of the "Pip-Squeak" aircraft DFing system the
Brits used early in fighter direction and which was adopted, though
I don't think much used, by the Americans.  It used a clock-work
thing in the inst. panel to key channel #4 for 15 seconds out of each
minute, so control could DF the aircraft.  The BC-616 provided the
relay switching to make it happen.

73 Dave S.