Thanks to all for the explanations. Brian Denley KB1VBF Sent from my iPad
> On Dec 18, 2016, at 8:46 AM, brian <als...@comcast.net> wrote: > > 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 b.den...@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
