[time-nuts] Any Spectracom hackers out there?

Bill Hawkins bill at iaxs.net
Sun Oct 24 15:29:44 EDT 2004


Just finished tracing the schematic of a Spectracom 8163 WWVB
receiver and standard comparator. The lock light on the 8163
runs off the receiver AGC line. There are two MC1496 phase
detector chips. One detects the AGC level and the other, 90
degrees over, detects the phase difference between WWVB and
the local 10 MHz VXO. This is done using 20 KHz reference
signals against 60 KHz (crystal filtered) WWVB. All dividing
is done with 74LS90 chips.

I'd expect the amplitude shifts for decoding time to come from
the AGC amp, leaving you free to disconnect the VXO and replace
it with precision 10 MHz. But there's a microprocessor in there
somewhere, so that's just a guess.

Be glad to look at a copy of the schematic and render an opinion
just for the chance to look at Spectracom documentation. Reply
and I'll send my address.

Bill Hawkins

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