[Milsurplus] SCR-240 oddness

[William Donzelli]

After many years of searching, I finally received a book on the SCR-240 
(and SCR-261, plus the maintenance sets). This set was the failed Command 
Set, built by Westinghouse. If it had not been such a dog (apparently), 
the SCR-274N would have remained just a dream, and the ARC-5 family would 
have been just a Navy set.

Here are some quick observations, as before this manual came about, I 
knew next to nothing about the set, barring what I could get from a few 
pieces I have picked up over the years (dynamotors, basically).

Its a box. Well, two boxes. This is probably the "first" black box radio, 
as the operator can do nothing with the transmitter or the receiver. The 
transmitters (BC-338-A and BC-353-A) have no controls on them. All tuning 
is done with special tools. A number of hatches open on the transmitter, 
giving access to the mechanical sockets that the tools mate with. The 
only features of the transmitters are the few binding posts for the 
antenna leads and the power/control connector.

The receiver (BC-225-A or BC-352-A) is just about the same, but is more
along the lines of a stripped down ARB. Once again, the only features are
a connection for the spline cable, the power/control connector, and a big
lump in the front that hides the tuning motor. 

Everything is controlled by the control box (BC-226-A or BC-351-A). This 
box is what would be expected - lots of switches, a couple big knobs, and 
a window for the tuning dial. The operator could control the transmitter 
channel (one of four crystal channels), or the receiver channel (one of 
three crystal channels or continous).

Other components include the I-71-A meter, a cockpit mounted thing for 
antenna current, the dynamotor (PE-59-A or PE-62-A), and the LP-16-A 
crossed loop. The mounts are FT-179-A, FT-180-A, FT-181-A, and the test 
mount called FT-182-A.

The tubes are VT-100s and VT-101s in the transmitters, and an assortment
of big pin and octal types in the receivers. It looks like the transmitter
is good for 20 or 30 Watts from 3 to 8 MHz, crystal controlled.  The
receiver covers this in a couple of bands, plus a 200-400 KHz and a
broadcast band (note it does not cover 500 KHz). 

Maintenance must have been horrible. Any radio described with "layers", 
as this one is in the manual, must be bad news. Much like the Navy's ATB, 
Westinghouse overengineered the hell out these sets. From notes in the 
manual it looks like several hundred were built. One of my dynamotors is 
from a second order from 1943 (the original is from 1938), so one has to 
wonder if some of these sets stayed in service thru the war.

Of course, I am interested in getting any of the bits of these sets, in 
any condition. Contact me off the list if you have any of these odd 
beasts...

William Donzelli
aw288@osfn.org