[Milsurplus] TS-186 & BC-221& LM: How'd they calibrate

[david_jackson at agilent.com]

George:

Jeremy Harmer generously made several .pdf files of the article that appears in Electronics Magazine in May of 1944 that went into some detail about the calibration process.  

There was a motor driven turns counter that was coupled into an NCR totalizer (calculator) that automatically determined when zero beat was accomplished and printed the results.  As I recall, it dropped the calibration time down from 12 or so hours to about 1 1/2 hours, most of which was typing the book.  If you re interested, I will email you the several .pdf files of the off the list because of the size of the files.  

Thanks,

Dave Jackson WA4OBJ

Date: Wed, 5 Jul 2006 02:54:22 GMT
From: "gl4d21a at juno.com" <gl4d21a at juno.com>
Subject: Re: [Milsurplus] TS-186 & BC-221& LM: How'd they calibrate
	'em?
To: Milsurplus at mailman.qth.net
Message-ID: <20060704.195441.18060.273015 at webmail60.nyc.untd.com>
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Is there a description of the machinery used to measure the frequency and print the calibration books for these?  Was it a strictly labor intensive manual method, or how much 1940s automation was there?  I presume the intermediate numbers were scaled by some mechanical divider (Monroe or Marchant, anyone?), but the measurement and printing must have been something to behold.  I don't think I have ever seen this subject discussed anywhere.

Duck soup now of course with PCs, even if the initial measurement run has to be manually done.  Getting two typefaces and two different variable density print shades so they look authentic might be a challenge, tho.

73,
George
W5VPQ