Andre Kesteloot wrote:
Stewart Bryant wrote:
Walter Blanchard wrote:
A number of TAIT T801 frequency
standards have just appeared on the UK surplus market.
They're ex-cellphone bases and
I
understand have been ditched in favour of GPS-locked standards.
It's more likely that they are now getting their clock from the PSTN
network.
Stewart G3YSX
but don't they rely on GPS for geographical location of mobile callers?
In that case, would they use two separate time references ?
Andre,
They do not provide the US style exact location service over here.
The only requirement on the EU systems is frequency. All of the
providers that I have spoken
to get this for free from the PSTN. When the network moves to VoIP via
metro Ethernet
that, as you can imagine, gives rise to a problem. GPS is unlikely to
be the solution for
many technical, economic and political reasons.
Now it's possible that they are doing timing measurement, or some
retiming because
of a network jitter problem.
It's also possible (and more likely) that these Rb systems are a relic
of their analogue
network (which did use free running oscillators) and which is being
cleared out
of the base stations to make room for next generation equipment. If
that is the case,
then there will be a lot of them, but they will all be quite old.
- Stewart G3YSX
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