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shortckt
Watchen Das Blinken Lights
Premium
join:2000-12-05
Tenant Hell

Time signals on digital OTA TV

I'm not familiar with the equipment used today in TV broadcasting stations, but what is it about synch'ing and broadcasting the correct time signals that is so difficult that many stations get it wrong?

Here in So. Calif. it seems only the national network broadcasters (NBC, CBS, etc.) get it right. Others, even the larger PBS stations are regularly off by minutes or hours, and/or don't change over to/from DST on the right date. It's to the point I've changed the time sync settings on the digital OTA box to 'manual' as it's easier and more accurate to set the time and change to DST myself.
/rant


OldCableGuy

@planetcr.net
Because even though they've used this equipment for 5-10 years now it's "new" to them and their processes don't list driving to the transmitter site and changing the PSIP encoder time.


Jahntassa
What, I can have feathers
Premium
join:2006-04-14
Conway, SC
kudos:4
reply to shortckt
Most digital gear is 4-6 years old now, hasn't been properly updated with the newer DST information, and possibly don't have the funds to spend on repairing or getting GPS locked time generators.


shortckt
Watchen Das Blinken Lights
Premium
join:2000-12-05
Tenant Hell
reply to OldCableGuy
said by OldCableGuy :

...their processes don't list driving to the transmitter site and changing the PSIP encoder time.

Seriously? In this tech age they can't do that remotely, have to hop in the 4x4 and drive up to the xmtr site?

said by Jahntassa:

Most digital gear is 4-6 years old now, hasn't been properly updated with the newer DST information, and possibly don't have the funds to spend on repairing or getting GPS locked time generators.

Let me guess: the companies that make these time sync generators charge $$$ for an update that could be made available on the net. Speaking of the net, why would they need to source the time sync from GPS? Anyone can get accurate, latency corrected time info from numerous sources on the net via NTP and other protocols. Since this method existed before GPS I would think equipment makers would have standardized on that, or WWV broadcasts which is an older system, if they didn't go with a self contained precision time ref in the equipment itself.

TheMG
Premium
join:2007-09-04
Canada
kudos:3
Reviews:
·NorthWest Tel
said by shortckt:

said by OldCableGuy :

...their processes don't list driving to the transmitter site and changing the PSIP encoder time.

Seriously? In this tech age they can't do that remotely, have to hop in the 4x4 and drive up to the xmtr site?

I too highly doubt that. More than likely they have all sorts of remote control functionality to minimize how often they have to physically go to the TX site(s).

said by Jahntassa:

Let me guess: the companies that make these time sync generators charge $$$ for an update that could be made available on the net.

Although I can't speak for TV broadcast equipment specifically, since that is not what I work with, that is unfortunately often the case with specialized equipment.


ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
reply to shortckt
said by shortckt:

Let me guess: the companies that make these time sync generators charge $$$ for an update that could be made available on the net. Speaking of the net, why would they need to source the time sync from GPS? Anyone can get accurate, latency corrected time info from numerous sources on the net via NTP and other protocols. Since this method existed before GPS I would think equipment makers would have standardized on that, or WWV broadcasts which is an older system, if they didn't go with a self contained precision time ref in the equipment itself.

Evertz has one that can source it's clock from GPS or NTP. But considering it's the "Rolls Royce" of master clocks, it's very expensive!
»www.evertz.com/products/560xMSC
GPS offers the most precision when it comes to time keeping. Whether the station chooses to spend their money on such gear or not is up to them, most don't because they can get "close enough" with a cheapie $1000 sync generator and manually update the time when needed.