LOL! Well, it really isn't nearly as "complex" as it may look/read.
The complexity is largely "self-inflicted" due to:
a) the inclusion of a number of steps that for "normal" (aka: non-OCD)
folks are OPTIONAL,
b) my tendency to use 10 words when 2 will suffice, and <smile>
c) the inclusion of many "beginner" button/dial instructions that most
K3 ops wouldn't need.
I wrote that specific procedure to amplify what the manual says about
"Method 2", and for use without any external instruments/devices. I
even wrote it to exclude more than a passing mention of the P3, which
can be used to great assistance IMHO.
While using Spectogram is certainly an option, I would prefer not to
insert anymore uncalibrated devices/items into the signal path than
necessary.
If I were going to use an external instrument, I'd just hook it up to
the HP5335a counter or the VNA. Most folks don't have these things.
Perhaps a second draft noting which steps are, strictly speaking,
"optional, and an abbreviated section that excludes all of the
"beginner" instructions for "Tap", "Hold" and button and dial callouts.
That would make the text a great deal less daunting. <smile>
Thanks for the feedback!
73,
______________________
Clay Autery, KY5G
(318) 518-1389
On 06/04/18 09:31, 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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