[Milsurplus] LM-13/CRR-10111

[Hubert Miller]

I have one of these also that i had been thinking i should dig out and sell. I have other heterodyne freq meters and don't need quite so many.
I was surprised how much this thing weighs - at least, mine does. The metal carry case seems to add a whole lot of weight to the little LM.
-H

From: Milsurplus [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Ray Fantini
Sent: Sunday, February 26, 2017 11:33 AM
To: Military Surplus Mail List <milsurplus at mailman.qth.net>; mrca at mailman.qth.net
Subject: [Milsurplus] LM-13/CRR-10111

Yesterday I picked up a LM-13, I always regarded the LM family of frequency meters to be a small version of the BC-221 full size frequency meter that was the standard for set up and calibration for more then a decade from WW2 on. The idea being that the LM was used by the Navy in aircraft for alignment of big transmitters like the TBW and later ART- 13 family of radios where space and weight were a premium.
The odd thing about this little LM is that its in a CPR-10111 carrying case that accommodates the LM, Batteries and calibration book that's about the same size and almost the same outward appearance as the BC-221, not the wooden case but the later aluminum skin version.
The questions are first, why did the Navy not just go ahead and use the BC-221 that the signal corps was using? Instead they went ahead and developed a ground or ramp base system to accomplish the same thing? Maybe it had something to do with the operators being familiar with the LM as opposed to the BC-221? Second, what came first the BC-221 or the LM? This LM has a contract date of December 27th 1939, when did the first BC-221 frequency meters start appearing? Is it possible that the LM series where in production and fielded before the BC-221? The wooden case BC-221 always appeared to me to be something that was designed pre war but how far pre war were they?
This little LM is in incredibly clean and unmodified condition and would tend to think it was never fielded in a military context. The unit has a Villanova University E.E. Department inventory sticker (#1475) and would tend to think was used by the university as opposed to the military.  It's hard to imagine today but in the thirties and forties Philadelphia and North Jersey were in a sense the Silicone valley of there day and lots of development occurred around there. This little LM was at the sale over at the NEM yesterday and no one else took it so it followed me home but if anyone is interested in it please contact me off list. It is complete, has the matching book, battery cables and all that sort of stuff.

Ray F/KA3EKH


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