[time-nuts] KD2BD WWVB receiver/decoder in QEX
attila at kinali.ch
Mon Nov 23 09:29:36 EST 2015
On Sun, 22 Nov 2015 13:05:53 -0800
Hal Murray <hmurray at megapathdsl.net> wrote:
> > I___d have to guess that the PLL would behave better given a 60 kHz reference
> > rather than a 1 Hz one. But how stable is that 60 kHz reference after going
> > through, what, a thousand miles of ionosphere or so?
> One of the reasons for using 60 kHz is to avoid the ionosphere. If you
> measure the propagation delay, it should be stable.
It is anything but stable, as other people have already written.
I have seen graphs for DCF77 that show "jumps" of 200-300us around
sunrise and sunset. Unfortunately, I cannot find any of them. The
only reliable data I could find is in  which shows uncertainties
of a couple of us during the day and close to +/-50us during the night
for a 273km distance.
 "Time dissemination via the LF transmitter DCF77 using a
pseudo-random phase-shift keying of the carrier", by Hetzel, 1987
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