Alberto,
Vernall wrote:
> The TVNZ nationwide network, with two Tv channels, has a Rubidium source
for
> timing.
In Italy, the state-owned TV broadcaster RAI has all its timings locked to
a central
Caesium standard, in Rome. Or at least so I have been told by a former RAI
employee.
I'm wondering if some simple circuit diagram is to be found somewhere, to
receive and
recover the synch timings, without using a real TV, bulky and noisy.
73
Alberto I2PHD
Alberto,
The relatively simple circuits I am aware of need a good quality composite
video signal to start with, then use line synch pulses to phase lock a local
10 MHz oscillator. There was a circuit in Radcom a couple of years back,
which seemed to be very similar to an Electronics Australia project from
1993.
The composite video could come from a VCR rather than a TV set. Running an
actual TV set in the shack would generally be shooting oneself in the foot
for LF QRM :-( Also you likely need much better than a piece of wet string
for the TV antenna, as noise or ghosting on the received video will not
result in a lab standard for the reference signal.
73, Bob
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