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

[Robert Downs]

Being written in 1996, it could be an MSDOS program or an early Windows one.
In either case, the XP box should run it.  That's one of the drawbacks to
WIN 10.  I have an MSDOS emulator that runs under WIN 10 but it wasn't cheap
and getting it set up wasn't a trivial exercise, either.

 

Robert Downs

 

From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Kenneth G. Gordon
Sent: Friday, May 22, 2020 23:38
To: Roy Morgan
Cc: ARC-5; Milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] [ARC5] BC-221 and LM calibration book

 

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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