[time-nuts] Time syncing WiFi routers using FM radio
Glenn Little WB4UIV
glennmaillist at bellsouth.net
Thu Nov 12 23:35:15 EST 2015
The house standard in some stations are no more than LC oscillators.
As long as the relative timing between signals is constant, you can do
synchronous switching.
All signals go through as dedicated frame synchronizer that is
synchronized to house reference.
At the last station that I worked at, our house reference had drifted
off where it should have been.
To reset it would have required retiming all of the production
switchers, the cameras and the on air switcher.
There was no cesium standard at the studio nor at the transmitter.
The transmitter was crystal controlled with the crystal in an oven.
Now there is no sync transmitted like in the analog days.
There is a very accurate pilot that can be seen in the signal.
The exciter is synthesized with a crystal bases reference.
Most transmitters can take an external reference, but, the stations that
I have worked for do not use it.
73
Glenn
On 11/12/2015 2:17 PM, Hal Murray wrote:
>> And the decade before that the hp house standard looked like this:
>
> Has anybody made a graph of the accuracy of house standards over time? I'm
> looking for something like Moore's Law.
>
>
--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv at arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
---------------------------------------------------------------------------
More information about the time-nuts
mailing list