If folks are particularly interested in frequency accuracy, a recent issue
of "QEX" discussed how to setup a GPS-slaved time &
frequency standard. A readily available surplus unit (used in the cellular
telephone industry) was featured in the article. The
unit provides a high-accuracy 10 MHz signal and time-of-day. These have been
advertised in "QST" and "QEX" for about $265 over the
last year or so. Achieving a stable and accurate local standard based on this
little rack-mount box would be much easier than
WWV-based solutions.
A very ambitious person would devise a system for slaving the Orion TCXO to
an external 10 MHz standard.
I have used double-oven 10 MHz local standards (also retired from the
telecommunication industry) whose accuracy was tracked
against WWVB at 60 kHz with a chart recorder. This approach is accurate enough
to observe the daily aging rate of the crystal
(after a few days of measurements). A WWVB-based calibration mechanism would
also be quite accurate, but it does require a recorder
and more time. The GPS-slaved system is much faster, which is why it is in
common use today.
-- Eric K3NA
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