[Elecraft] Zero-Beat Procedure for the Elecraft K3s (DRAFT)

Bob McGraw K4TAX rmcgraw at blomand.net
Mon Jun 4 11:03:09 EDT 2018


The article I wrote and was published in QST, September 2015, gives 
guidance to a method to determine the accuracy or lack there off, of 
ones radio.    Later the Freq CAL mode now available in WSJT-X does and 
even better job.    I've used this latest method, WSJT-X Freq CAL,  with 
a high degree of accuracy with my K3S. Simple, easy, fast and done with 
most likely available software and computer configuration.

73

Bob, K4TAX



On 6/4/2018 9:31 AM, Don Wilhelm wrote:
> Clay and all,
>
> That is good work, but I feel it is overly complex.
>
> The secret to using the zero-beat method for the Reference Oscillator 
> is in the ability to correctly tune WWV (or other standard station) to 
> zero-beat.
>
> I make use of an audio spectrum analyzer running with my PC and 
> soundcard.  Spectrum Lab will do fine, but I use Spectrogram v16. For 
> those who want Spectrogram 16 or 5.17, they are available on my 
> website www.w3fpr.com - scroll down near the bottom of the opening 
> page and you will find the links.  Those files are local to my website 
> and have been scrubbed many times for virus.
>
> With Spectrogram running, first tune WWV and feed the K3 audio to the 
> soundcard input using SSB mode.  Knowing that WWV transmits 500 and 
> 600 Hz tones with a 1 second 1kHz tone at the start of each minute, it 
> is easy to properly tune WWV (in SSB mode).
>
> Now switch the K3 to CW mode, and you should see the carrier displayed 
> at your sidetone pitch on the Spectrogram screen. Adjust the tuning 
> slightly if not true.
>
> Now that WWV (or other standard station) is tuned properly, lock the 
> VFO and follow the other instructions in the Zero-Beat (Method 2) in 
> the manual.
>
> All done.
>
> 73,
> Don W3FPR
>
> On 6/4/2018 12:32 AM, Clay Autery wrote:
>> It was not until recently that I acquired the TMP connectors and 
>> crimp tool to make a proper jumper cable from my K3s' J1 connector on 
>> my K3s’ TXCO (TMP) to my frequency counter (BNC), so I have always 
>> used the "zero-beat" method. Periodically, I go back and repeat the 
>> TXCO calibration using a modified "Method 2 (Zero-Beating)" procedure 
>> (K3s Owner's Manual, Rev A1, p.53).  It originated (and grew) from a 
>> post snippet from this reflector. (Thanks Scott, K9MA)  IF you have 
>> an Elecraft P3 Panadapter, or other, connected to the K3s’ IF Out, 
>> you can use it to great facility in visualizing and verifying what 
>> "is" and what you "do".  I have written this procedure with the 
>> assumption that the P3 is not present or is not being actively used 
>> beyond observation.  I may write an addendum later to include the 
>> active use of the panadapter vs. as an observational tool only.
>>
>> For obvious reasons, the manual says to use the highest WWV frequency 
>> available, and references 10, 15, and 20 MHz.  Just in case you 
>> missed it, NIST put WWV at 25 MHz back on the air sometime in 2015, 
>> but they switched it to circular polarization around July of 2017.  
>> Link: 
>> http://www.arrl.org/news/wwv-25-mhz-signal-swapped-to-circular-polarization 
>> OR, back to the half-wave dipole depending on which reference you 
>> read. <confused>  Point is, that I am having great luck using it as a 
>> reference signal.
>>
>> Of interest to some may be the inclusion of a very simple equation 
>> that tells you how much and which way to adjust REF CAL in one shot.  
>> No fuss, no muss, no futzing around and back and forth. You make one 
>> observation, one calculation, one input and you're done.  (Usually) 
>> MOST of the procedure is in the setup.
>>
>> Go here to grab a PDF of the DRAFT document of the procedure I use: 
>> http://www.montac.com/pdfs/Elecraft_K3_Zero_Beat.pdf
>>
>> 73,
>>
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