adequate is not perfect. YMMV Sent from my iPad
> On Jun 10, 2020, at 2:07 PM, Bob McGraw K4TAX <[email protected]> wrote: > > In referencing TF.NIST.GOV on page 251, I find it stated; > > "When high accuracy is not required, probably and fastest way of comparing > the frequency of an oscillator to a broadcast standard is the familiar > heterodyne or zero beat method. " > > And then on page 253, I find it stated; > > " Usually, however, it is difficult to adjust an oscillator to exactly zero > beat with an HF carrier beyond the ground wave range of the transmitter. The > problem arises from rapid fluctuations in the received signal strength and > from propagation flutter in the received frequency." > > References are: THE USES AND LIMITATION OF HF STANDARD BROADCAST FOR TIME AND > FREQUENCY COMPARISON. John T. Stanley, NIST. > > As I indicated earlier, a frequency accuracy of +/- 1 Hz for ham radio > purposes is adequate. Likewise for time accuracy +/- 0.1 second is adequate. > > 73 > > Bob, K4TAX > > >> On 6/10/2020 11:52 AM, w4sc wrote: >> How much doppler shift should be expected? >> >> Sent from Mail for Windows 10 >> >> From: W2xj >> Sent: Saturday, June 6, 2020 5:31 PM >> To: w4sc >> Cc: [email protected]; [email protected] >> Subject: Re: [Elecraft] K3(s) main oscillator calibration >> >> the problem with WWV is doppler shift. >> >> Sent from my iPad >> >>>> On Jun 6, 2020, at 5:27 PM, w4sc <[email protected]> wrote: >>> >>> I like the zero beat WWV method. Used it in the Navy to calibrate / PM >>> the 10MHz frequency standards aboard ship. Requires the least amount of >>> test equipment! If you can receive WWV on 20MHz to calibrate the K3/K3S, >>> all the better, >>> >>> Using a frequency counter I would think 0.1Hz resolution and attending >>> accuracy would be in order, plus an accurate time base in the counter, GPS >>> locked,,, or oven-ized, on all the time reference ,,, ect. >>> >>> Ben W4SC >>> >>> >>> Sent from Mail for Windows 10 >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to [email protected] >>> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
