[time-nuts] TV Signals as a frequency reference

[Gerhard Hoffmann]

Am 31.03.2018 um 00:13 schrieb Hal Murray:
> fgrosz at otiengineering.com said:
>>    Now that analog TV has gone away, so
>>    have these signals.
> What do the local TV stations use for a frequency reference?
>
> Are there low cost receivers that also produce a good reference frequency?

The German channel ZDF was known to have their line frequency
derived from a Rubidium, when received from the air.
But already on cable, there might have been elastic buffers.

Now with sat and terrestrial TV gone digital, there is no such
thing as a line frequency in the MPEG data stream.
You are 30 years too late  ;-)

But you can find the pseudo noise of the satellite's own
navigation loops abt. 20 dB below the MPEG.
If you know the polynomial, you are back in time nuts land.

The 20 dB are enough that there is no interference. I wonder
how many secret services are parasites on the commercial
TV transponders. The power required for 1 Kbit/sec of
stealth transfer should be much, much lower. Even less when
you just want to disseminate a new key, with the mass transfers
done somewhere else.  Nobody would notice that. Just use
your own polynomial. With a dish on  every house that already
points to the right direction, you just need a modded feed unit.
If that is not tempting!


regards, Gerhard