[Milsurplus] [ARC5] BC-221 and LM calibration book

[Kenneth G. Gordon]

On 23 May 2020 at 0:25, Roy Morgan wrote:

> Ken,
> 
> If you don´t find it I have it here.  There were updates from the original one Bob Keys wrote.

Hi, Roy: I found it, but I don't know if it contains the updates you mention.

Also, I attempted to run the .EXE file on my WIn10 box and was told, rather bluntly, that it 
would not run there. I have an XP-Pro box I'll try next.

My versions were published by Russ Schroeder  W2DYY dated 9 Feb 96

Is that the one you have, or is mine older than yours?

BTW, Russ' notes include the followng:

"The calibration book you generate will not be as accurate as an original
book.  However, the maximum error in the HF range should be less the 0.5 kc
at the ends of the range.  The maximim error in the LF range should be less 
than 50 cycles at the ends of the range. This error is due to a small 
nonlinearity in the capacitor manufacture."

> I have both an SP-600 (not nearby but safe) and a BC-779 (here), so I
> would like to collect full details on this crystal filter problem. 

I'm sorry, Roy, but I don't have the details on what Woody discovered about the filter.

I DO remember, vividly, that he told me that if the filter is aligned correctly, as you reduce 
the bandwidth, the signal level should rise on the S-meter, NOT get weaker, since the S/N 
ratio is increased.

I also remember that it took him some weeks to get what he expected and that he was very 
happy when it finally worked as he thought it should.

This was at least 50 years ago, so I don't remember much about it.

Ken W7EKB

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