Christian Vogel wrote:
Hi Alan,
I cant remember the detail now but my converstaion with a BBC engineer at
the NPL meeting a few years back suggested along the lines of "yes there
would be a stable frequency available on a digital TV signal but no it
would
not be related (tracable) to any given standard because it didnt need to
be."
at least here in Germany the digital TV transmissions (DVB-T) are using
(in some areas) Single Frequency Networks[1]. I live near one of the
transmitters
and when I visited the facility, they had Meinberg GPS receivers in the
racks housing the TV signal generators.
SFN requires synchronisation of frequency (10 MHz) and phase (PPS).
DVB-T transmitters using SFN will broadcast pilot-tones. See ETSI EN 300
744, accessable through:
http://www.dvb.org/technology/standards/
Speaking of alternate sources: Has any time-nut considered using the ISDN
telephone network [2]?
I think ISDN is finally dead here in Sweden. I can check if my ISDN
connection is out for good. However, I wonder if the modern replacement
to ISDN, such as ADSL is actually synchronised. It too uses OFDM/COFDM
transmission and provides pilot-tones.
Chris
[1] http://en.wikipedia.org/wiki/Single-frequency_network
[2] http://openbsc.gnumonks.org/trac/wiki/isdnsync
Cheers,
Magnus
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
