[time-nuts] WWVB phase-modulation test
jxh at jxh.com
Sun Apr 15 16:59:34 UTC 2012
>psk fixer-uppers not working all that well. Back to the drawing boards as
My Spectracom 8170 was showing lock but not time sync, for a while last night,
several hours. Longer than usual, when it's just getting a grip. (I didn't set
up to record its outputs, alas!) At other times, and this morning, it's just
The 8164 has been unlocked throughout, as expected, and its strip-chart recorder
shows the usual open-loop pattern. When the test ends I should have a nice
picture bracketing it.
My MFJ-133 clock is happy enough, as predicted. The Junghans Mega seems to be.
It's harder to tell with the others, that only have hands and no direct
indication of receiver state.
Interesting that the NIST's own monitoring stations
(http://tf.nist.gov/tf-cgi/wwvbmonitor_e.cgi) variously show readable time
codes, and highly atypical plots of relative field strength. I wonder how
they're measuring those. Again, LaCrosse is the big loser on readability, for
I also finally hauled the spectrum analyzer (HP 141T/8552B/8553B) up from the
basement, got together a DC block and a BNC tee, and tried to see what I could
see. Nothing. 60 kHz is mighty close to DC, on this thing. Too close,
evidently. Perhaps I should be looking somewhere inside the 8164.
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