[Elecraft] K2 Frequency Alignment

Mon Jul 28 16:03:00 2003

Which is why I use very loose almost non-existent inductive coupling to the
"vicinity" of the circuit and take the output into the high-gain PRO2
receiver for analysis and measurement against WWV, etc.

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
<mailto:[email protected]>

----- Original Message -----
From: "Don Wilhelm" <[email protected]>
To: "Masleid, Michael A." <[email protected]>;
<[email protected]>
Sent: Monday, July 28, 2003 2:49 PM
Subject: Re: [Elecraft] K2 Frequency Alignment

> Michael,
>
> You have hit the nail on the head.
> Attaching anything to the 4 MHz oscillator circuit will pull its
> frequency!!!
> My rule of thumb - never attempt ot measure the frequency of an oscillator
> by connecting to the oscillator section - measure after a stage of
> buffering, or use indirect pickup methods.
>
> Sooooo - when one attaches a probe, adjusts it to exactly 4000.00 kHz,
then
> removes the probe, the oscillating frequency is NOT 4000.00 kHz anymore.
>
> Bottom line - don't do it that way!!!  Apologies to the experienced folks
> who already know that, but I fear there are several looking and listening
> who are not aware of the consequences.
>
> Since CAL FCTR is only accurate if the 4000.00 kHz oscillator is correct,
> using CAL FCTR to measure a known external frequency (such as a stable
> oscillator) and adjusting C22 until the display shows the correct
frequency
> of that external oscillator is an excellent method.
> Just be certain that you do know the frequency of that external
oscillator.
> The finished product is only as good as the tools used to produce it.
Every
> good engineer and technician knows the limitations of his measuring tools
> and tries not to draw conclusions outside those limits.
>
> 73,
> Don W3FPR
>
> ----- Original Message -----
> The bottom line, I think, is that if CAL FCTR doesn't show 4000.00 KHz
when
> you
> probe the 4 MHz oscillator that runs the MCU, the setting the 4 MHz
> oscillator
> exactly to 4 MHz won't work too well.  It is better to attach the probe
> to some other oscillator, with a known value, and adjust C22 so that CAL
> FCTR
> matches the known value.
>
>
>
>
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be a list member to post to the list.
> Postings must be plain text (no HTML or attachments).
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com