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).

Cheers, Ken
vk7krj@southcom.com.au