[ARC5] The not-so humble BC-221/LM-xx frequency meters.

[Richard Knoppow]

    Good for you for finding this stuff. BTW, I am quite familiar with 
the blue print printers using ammonia having been practically suffocated 
by one at a place I worked.
    I have some stuff on early crystal development which I will either 
send you or send links to it. One is a paper by Virgil Bottom, 
originally published by the IRE, talking about the problems they had 
during WW-2. Crystal control became absolutely necessary  but no one 
really knew how to make them.  At one point the research group decided 
they needed a General Radio primary standard but it was refused, 
something called the Manhattan Project had a higher priority. He said it 
was years later they found out what this was.
     I have always been fascinated by Newton. An odd man but absolutely 
brilliant, up there with Einstein IMO.  One thing I learned from physics 
and some very smart friends is that the popular version of some theories 
are really special cases, simplified because the math of the full theory 
was intractable at the time. It is frustrating to me that I am not quite 
smart enough to understand many things that fascinate me.
      There is some information on the 1100-A at
http://www.ietlabs.com/genrad_history/historic_manuals/
     Maybe the same as you have but no blue prints:-)
     The 1100AP and 1100AQ standards are the same except the P does not 
have the synchronometer, the synchronous clock/cycle counter. Of course 
it could always be added. There is no difference in the accuracy and 
stability of the standards.  This site also has a number of GR catalogs, 
the earlier versions of the frequency standard are in them. They also 
describe the frequency measuring equipment available for use with the 
standard.
     There is a little about the LR-1 at
http://www.radioblvd.com/vintage_test_equipment.htm
     Is the Feynman lecture on You Tube?  I would like to see it.
     In the dim, distant, past I learned the Greek method for 
demonstrating prime numbers in a number theory class I took. I wish I 
could remember more but maybe its still sticking in there somewhere.
     Maybe more later, probably off list.




On 12/24/2016 4:44 PM, Leslie Smith wrote:
>   Hello Richard,
>   Following your lead I found a 16 page document, Instructions of 1100A
>   Frequency Standards.
>   Date:  (for this specific document) December 1947.
>   The drawings in the document have been done on linen and reproduced
>   using an ammonia-printer!!  (They are blue!!  How's that for
>   authentic?)
>
>   The document mentioned a primary standard (1100AP) and a secondary
>   standard (1100 AQ).
>   I take it that "P" designated 'primary' and "Q" just followed "P".
>
>   I have seen a lecture by Richard Feynman, where he referred to the
>   actual words used by Isaac Newton discussing the nature of light.
>   Feynman was clearly trying to get inside Newton's head.  He referred
>   to words that Newton "invented" (one was "fit" or "fits" - used in
>   conjunction with light - so "fits of light".  Newton believed in the
>   corpuscular theory of light, (as we all know) and Feynman was trying
>   to understand how Newton understood these things he called "fits of
>   light".
>
> The interesting thing about this is that we (modern) types can learn a
> great deal by understanding the equipment and methods of the greats from
> times past.  For example the Greek method for demonstrating that there
> are an infinite number of prime numbers is understandable, convincing
> and very clever.
>
> You observe that measurement to within a few parts in 10e7 is possible
> with care.   That's the interesting point.
>>From time to time I work on an analytic instrument that can resolve 1/2
> Hz at 90.000MHz.  Very precise, but not necessarily accurate.
> Understanding the entire system well enough to make a measurement with
> that degree of precision is interesting.
>
>   I don't have a lot of money lying around, but that doesn't mean I
>   can't get a great deal of enjoyment doing "interesting stuff".   (Like
>   figuring out what was in the mind of the fellow who designed the LM/BC
>   frequency meters).
>
> Thanks for the idea that I should look to General Radio for info.
> Incidently, GR made the LR-1 heterodyne frequency meter - a rather
> thoughtful design that uses the same principle as the LM series of
> meters - but more precise and easier to use.  (And heavier and more
> expensive!!!)
>
>
>   73 de Les Smith
>    vk2bcu at operamail.com

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL