[ARC5] Unusual BC-221

[Bill Cromwell]

Hi Roy,

A couple of other hams asked about the same thing in private posts. I'm 
busy as a cat on a tin roof but I will make it a priority to put 
together some kind of small "document" to better describe what I did. I 
think "Spectran" or "Spectrum Lab" (also known as "SpecLab") are the 
best choices of soundcard software with Spectran being the easiest to 
learn and use. Both are free for a download. One or both are MS Windows 
software but I run Windows programs on WINE in my Linux boxes. I'm sure 
*everybody* can run them regardless of their favorite operating system. 
I suggest getting that and getting it running on your computer. Fldidgi 
might not work well for this since it doesn't have a spectrum display. 
The waterfall - a kinda-sorta spectrum display - might not get you as 
close but we can give it a try.

Now posting to my whiteboard so I don't forget!

73,

Bill  KU8H


On 03/04/2015 11:04 AM, Roy Morgan wrote:
> On Mar 4, 2015, at 6:47 AM, Bill Cromwell <wrcromwell at gmail.com> wrote:
>
>> .... My calibration has evolved to using one of two computer sound card DSP  programs and WWV.
> Bill,
>
> I’d like to know enough of the details to be able to make such a setup here.
>
>> I set up my sound card program and radio so I can hear and display the WWV carrier - not at zero cps on the sprectrum but usually near 1 kc. The exact tone matters not.
> Do I understand you are feeding the audio from the LM earphone jack to the audio input to the computer?  Is it an audio spectrum analyzer program on the computer?  (I don’t have one but can find one -I use an Apple computer here. I do have FLdigi - maybe that would work.)
>
>> The xtal marker from an LM (or other source) is brought into play.
> So you turn on the crystal calibrate function.
>
>> Tweaking the xtal onto WWV will show the pip for the xtal creeping onto WWV's carrier
> And there’s an antenna feeding the RF input/output of the LM so it can pick up the WWV signal off the air?  Oh, you mention a receiver below: the LM signal and the off the air signal of WWV mix in the receiver?  So the sound card gets the audio from the receiver?
>
>> and then a moire pattern will be seen advancing up the slope to WWV's peak.
> Maybe you are using the BFO in the receiver and getting a 1 kc beat note from the carrier, then the LM signal is adjusted to match that same beat note, whatever it might be.
>
>> When it reaches that peak - "on frequency" the moire pattern will stop crawling and stop "wriggling". Never mind about calibration of the receiver, the sound card, or anything else. If any of that moves WWV will move with it and will will still be the "target”.
> You mean the beat note produced from the WWV carrier in the audio output of the receiver?
>
>> After all these years a good LM (or 221) is hard to beat.  They do tricks a digital frequency counter can’t.
> As I mentioned, I have a very nice LM here, with correct cables and power supply.  Just as old as I am!
>
> Roy
>
> Roy Morgan
> k1lky68 at gmail.com
> K1LKY Since 1958
>
> .
>