[ARC5] [Milsurplus] SCR-287 (BC-375 & BC-348) WW II Operational Question

[Hubert Miller]

Not a whole lot is known about the CMS. The schematic looks like it was drawn around 1930, but that's obviously not the case.
As i may have mentioned here before, its ability to use a variety of 1 and 6 volt tubes, both triodes and pentodes, in the transmitter,
"may" follow a QST magaine idea from around 1938 - 1940 on an "emergency transmitter". I have this date issue, but it's somewhere
else right now. Since it's USN, i my suspicion is that it was for China or Philippines use, where it was a U.S. Navy game until maybe 
1944. SACO, the name just came to me. "Sino - American Cooperation Organization", i guess. BTW, the ONLY photo of the Navy DAG i 
have ever seen was of some Navy chap teaching a Chinese national how to use. Like it was actually going to be used by Chinese 
nationals - fat chance of that. I think more like, "This is a required course / this is a way to prove we're actually doing a job out here". 
Anyway, CMS. The plastic protector over the key is pretty hokey. The light bulb with loop for tuning the final is pretty hokey too. And
the regen receiver with tuning and regen controls only - no gain control - that went out about 1932. Anyway there would be scant need
for use of such a radio in China, so my guess it was designed in a hurry (  like "Hell of a Rush Order" ?  ) when the Philippines fell and it
was learned there was a resesitance still hiding out. Then was declined for actual issue, because, well, of the "amateurish" aspects i
mentioned. 
The MBM history in the Philippines is almost totally unkown too. The manual's directions for tuning up the transmitter is non-obvious
even to me, and i think before i memorized the operation, when using it, i would have to read the instructions carefully. It uses the
L network same as on the ART-13 and TBX, but i think it was maybe thought the user would be a total ignoramus and therefore, why
not confuse him some more ? And what genius thought you could walk thru Manila carrying a large, new, American - looking suitcase ?
Like the Japanese soldiers would merely remark, "Well, my goodness, there's something you don't see every day !"

The AC supply for the CMS was developed for some covert operations school or some such. I'm sure you can find more about it on the
net.
Photo is not my set. I don't think i have the 'test meter'; i think the space is taken up with transmitter coils, test lamp and such.
My archive indicates the article i saved is from 'Wireless For The Warrior', Louis Meulstee;  WftW Volume 4 Supplement, Chapter 219.
ver 108 Dec. 2018
-Hue Miller 
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