[Milsurplus] BC-938A, BC-616

[Jack Antonio]

On the RC-96 "Pipsquak" with the
SCR-274N.

The BC-616 relay unit does a couple of things. At the
start of the 14 second period, the system is placed
in transmit mode, with tone, on the channel selected
on the control head, for about 1 second. It then switches
to channel one, un-modulated for the rest of the period.

What I'm not sure of is whether the transmitter mode is
changed to CW, or is left in MCW with the tone muted for
the quiet period. All my manuals are packed right now, and
I won't be able to get to them till this summer.

On Pipsquak with the SCR-522, there was an early and a late
version.  The functionality of the BC-616 was built into the
early SCR-522 transmitters, but these relays were later eliminated,
and the pipsqueak simply keyed channel 4 for 14 seconds out of each
minute. I'm not sure if the transmitter was tone modulated or not.

I have seen no concrete information on USAAF usage of the system,
but have seen references to British and Australian usage.

I had an SCR-274N with Pipsqueak on display at MRCG back in
2004.

Jack Antonio WA7DIA



WA5CAB at cs.com wrote:
> Dave,

> SCR-274-N.  I think the "channel #4" Dave mentions refers to SCR-522.  I 
> don't know which transmitter of SCR-274 was, by default, keyed but presume it 
> would have been #1.  As single and two-transmitter installations would 
> appear to have been more common than four-transmitter ones.