On Wed, 28 Oct 1998, Ken Johnson wrote:

> There is a very good frequency "standard" in most homes, in the humble
> colour tv. The colour burst crystal is phase locked to the stations master
> oscillator, and (at least here in Australia) that can be traced back to a
> very accurate standard. IIRC, here it is a rhubidium standard, I guess it
> is the same in most countries.
> A crystal oscillator phase-locked to the colour-burst crystal will give an
> accuracy better than the all but the best temperature-compensated crystal
> oscillator (but only when the tv is receiving a colour picture of course).

This is very correct in the USa and other places which have NTSC and is
incorrect for Australia and places which have PAL because the color
decoder crystal is phase modulated at +/-90 degrees every other line, and
this phase modulation is a pain to remove for other uses.

*However* if a local radio station is strong enough then its carrier can
be received in a direct conversion receiver and divided directly. Provided
it is not some pirate transmitter, it should be linked to a very good
frequency standard in most countries. AM is better than FM here and AM
beacons are best (such as used for naval and aviation purposes).

BUT I was interested in a stand-alone, simple set of methods.

Peter