[ARC5] IF "overcoupling" in BC-453B

[Jim Mandaville]

Can anyone tell me which, if any, of the IFs in the BC-453 (0.19-5.5 Mcs)
are supposed to be placed in "overcoupled" position after alignment?  I
have instructions for the R-23 and R-23A but don't know whether the same
thing applies for the BC-453.  In any case, for CW use, wouldn't it be
better to keep the IFs loosely coupled for better selectivity?

By the way, I completed recapping and realignment of the BC-453B today, and
it's working great with no trace of the previous noise and RF stage
instability.  I'm now using B+ of 220 v. and 25 vac on the heaters.
Replaced all caps except the micas.

Someone asked yesterday about how often CW was used in aircraft with
command sets.  I would guess that the average lone fighter pilot knew
enough morse to identify beacons but that he almost always used AM in the
air.  Planes with a  radio op. would probably use CW for increased range
when required.

Speaking of planes, can anyone tell me a bit about the power source for the
28 vdc in single engine WW2 planes?  Did they have a DC generator and a
battery for 28 v (13 wet cells?? :)?

Many thanks again to Dave for his ideas on the "heater wiring chirp cure"
and how to connect an antenna to the transmitters (the latter anticipated
another question I had :).

Jim Mandaville, KF7A