Expectations may be too high.....
All these WWV methods assume there is no Doppler shift present on the
WWV signal. Other things to consider: TCXO drift, synthesizer
limitations and new synthesizer quirks.
During disturbed times, Doppler could be 1 Hz or more.
Unfortunately, the Doppler shift present depends upon just about
everything-- location, time of day, atmospheric reflecting layer
heights, path, the list goes on.
Keep in mind the new synthesizers add an additional quarter Hz (+/-)
uncertainty. The syncing of the SI570 to the master oscillator produces
sawtooth jumps of that magnitude, sometimes more vs time.
There are also band to band variations introduced by limitation in
finding exact synthesizer divide ratios. Old synthesizers showed many
Hz deviations from band to band and as one tuned up the band. These
variations are much smaller with the new synthesizers.
Then there is drift. If you are not using XREF, you will experience
maybe 10 Hz or more warm up drifts. The high stability oscillator takes
about four hours to reach its most stable point. The standard
oscillator reaches that point a few hours earlier.
The old engineer cautioned: "Never believe the last digit displayed in
any device". In this case, don't expect to be within 1 Hz on all bands,
all frequencies at all times-- no matter what calibration method you
use. Look at the K3 specs. Nowhere will you find an expectation of
such accuracy.
73 de Brian/K3KO
On 12/18/2016 12:40 PM, K9ZTV wrote:
The R.L. Drake Company referred to the zeroing or beating indicators as "canary chirps," the goal
being to slow the "chirping" until there was a steady tone indicating you were then dead-on. I
still find that the most descriptive way to tell someone how to identify the pulsing when doing the Reference
Calibration against WWV in a K3 (at the highest frequency you can copy them). The trick is to get the right
balance in volume between WWV's main carrier tone and the K3's sidetone so you can hear the
"chirps."
Kent, K9ZTV
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to als...@comcast.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
