Unfortunately cesium passthru went away with the advent of the
use of frame synchronizers to receive the network signal and then
re-clock it to match the local sync generator phase and frequency.
The FCC requirement for the color burst signal (3.579545 MHz)
is plus/minus 1 Hz... and you can
Don,
I think
you might have dropped a zero there typing, They actually allow
us
+/- 10 Hz on burst.
Best Regards,
Mark
Unfortunately cesium passthru went away with the advent of the
use of frame synchronizers to receive the network signal and
then
re-clock it to match the local
Aficionados of accurate time,
I have two Panasonic DVD TV recorders, a DMR-EZ27 and 28. They were set to
automatically sync time to a TV station. This worked fine until a few months
ago. Now they are on manual time, but, of course, they drift.
Tried to turn automatic time setting back on this
Hi Bill,
I have no direct knowledge of the situation, but I have noticed that
in my area the time signals seem to piggyback on the PBS stations, and
in my area many of the PBS stations have ditched their analog signals
earlier than the FCC mandate for digital TV.
-Chuck Harris
Bill Hawkins
On 5/25/09 9:52 AM, Bill Hawkins b...@iaxs.net wrote:
Aficionados of accurate time,
I have two Panasonic DVD TV recorders, a DMR-EZ27 and 28. They were set to
automatically sync time to a TV station. This worked fine until a few months
ago. Now they are on manual time, but, of course,
Why did TV stations stop broadcasting time signals? HDTV requirements?
One thing that may be relevant
Many years ago, all the TV sources were kept in sync so there wasn't any
glitch when they switched feeds. The sync timing was distributed from at
atomic clock at network headquarters.
didn't have purple hair !!
73, Dick, W1KSZ
-Original Message-
From: Hal Murray hmur...@megapathdsl.net
Sent: May 25, 2009 2:14 PM
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] Time Signals on TV signals
Why did TV stations stop
The NBS published a booklet on constructing a device that could receive
the sync signals and provide a reasonable secondary frequency standard.
I still have that book around in some box. I should look for it.
IIRC, the signal originated from a Cesium standard and was used to sync
the color so
It appears that the time information is transmitted in line 21 of the
analog TV signal.
This is the same line that carries Close Captions in an analog signal.
It further appears that PBS is the major carrier of these time signals.
See :
I think you're talking about the VITC, which is on lines 19 and 20 (so you
get it on both fields with interlacing). VITC carries
hour/minute/second/frame (same as LTC), but I don't know if it's program
time (since start of program) or real time).
There's a bunch of flavors of vertical interval
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