[Milsurplus] Even Worse

[jcoward5452 at aol.com]

 Where I actually work, we do have a "house"10 MHz GPS derived reference and it is "plumbed" to all the benches that build frequency counters and signal sources. All the instruments that have internal clock modules have to be zero beated to the house standard in the free running mode.These are microwave instruments where accuracy counts.
Jay KE6PPF





-----Original Message-----
From: J. Forster <jfor at quik.com>
To: sdaitch at kuw.ibb.gov
Cc: milsurplus at mailman.qth.net
Sent: Sun, Jul 4, 2010 11:37 am
Subject: Re: [Milsurplus] Even Worse


I have no doubt that some communication systems require very good clocks,
ut in this case, the clock is being used to "synchronize" things like CD
nd record players and possibly a digital mixer in a house. It's not like
he boxes are separated by more than a few score feet.
I could possibly see it in an all-digital recording studio, but even there
t's likely huge overkill.
-John
===============

>

 Many digital communications systems have GPS related time bases, I can
 guess only to eliminate digital jitter in recovering the synch timing from
 an incoming data signal.
 Quite a few years back, I was acquainted with a DS-3 capable digital
 microwave system, which originally was using LORAN receivers to establish
 the timing signals for the terminals.  At one particular installation,
 there was so much interference at 100 kHz that LORAN was useless.  A
 cesium beam standard was installed for the timing signals and that was in
 use until the system was deactivated.
 This microwave system supported mostly telephone circuits, I was told, and
 we know what the freuqency response and distortion requirements are for a
 telco circuit.
 73
 Sheldon


 ----- Original Message -----
 From: "J. Forster"
 Date: Sunday, July 4, 2010 0:31 am
 Subject: Re: [Milsurplus] Even Worse

> But that's not nearly Audiophool grade!
>
> I was talking about syncing the internal CD and record player
> clocks to GPS.
>
> -John
>
> ===============
>
> > The power companies already do that and is able to compare phasors
> > across the grid. Check out NASPI, the North American SynchroPhasor
> > Initiative.


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