Posted by
Darrell Bellerive on
Apr 25, 2006; 5:50pm
URL: http://elecraft.85.s1.nabble.com/Need-help-for-sick-K1-tp389102p389117.html
Thanks Nick and Don for the explanation of the accuracy of the soundcards and
K2 sidetone.
On April 24, 2006 11:40 pm, Nick Waterman wrote:
> ... but it'll be within a few percent, surely, and that means you'll be
> within a few hertz of 100Hz? The K2 tuning steps are likely to be a lot
> bigger than that?
Theoretically if one could tune WWV to .001 Hz accuracy and have the manual
dexterity to set C22 as accurately, then at the frequency of 10,000,000.00 Hz
one would be within +/- .002 Hz. Now because the K2 does not tune in precise
10 hz steps, 10,000,010 Hz would only be as accurate as Wayne's algorithms
and PLL calibration allow. This is all assuming that there is absolutely no
change in frequency caused by temperature or any other means. Then again, WWV
is only accurate as received to +/- 1Hz (1 part in 10 million).
>
> I think you'll find day-to-day temperature variation, and
> capacitative/inductive effects of nearby objects probably cause more
> variation than that :-)
Yes, that is the reality of it.
Amazing how digital readout has changed the way we look at our frequency of
operation. Wonder what the typical accuracy of the digital readouts of the
commercial (Kenwood, Icom, Yaesu, Ten-Tec, etc.) is?
My first receiver was a Hallicrafters SX-140 and that was followed by a
Heathkit SB-101. One was dependant on the crystal calibrators for frequency
accuracy. The Hallicrafters used a 3.5 Mhz crystal to set the lower band
edges. There was no trimer to adjust the 3.5 MHz crystal. So at 3.5 MHz one
was as close to 3.5 MHz as the crystal oscillator tolerance. At the 4.0 MHz
end, it was dependant on the VFO and alignment. No spec was listed in the
manual for the frequency accuracy. Wonder what it was at 4.0 MHz, or at 54.0
MHz. 10 Hz, 100 Hz, no way. 10 Khz more likely.
Darrell
--
Darrell Bellerive
Amateur Radio Stations VA7TO and VE7CLA
Grand Forks, British Columbia, Canada
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