[time-nuts] time-nuts Digest, Vol 114, Issue 3

BD Systems Inc. bdsysco at yahoo.com
Thu Jan 2 10:27:26 EST 2014


Re: Measuring TV delays

There's more delay involved in a live feed than most people assume.  Let's start with the live feed or remote.  Most live feeds with live crowds will use a 9 - 10 sec delay to avoid FCC issues with language.  Then it's usually one satellite hop (1/4 sec) to get to the broadcast control center.  Frame syncs usually add a 1 or 2 frame delay.  Distribution to local stations is usually done with another sat hop.  The local station does a pass through (to enable their local ads) and if you get it off-air then you're done.  If you get their signal via cable (Comcast) or DTH (DirecTV) there is at least one more sat hop to go.  If your set top box (IRD) has delay capability (TIVO), add another 1/2 sec.

BD Systems



On Thursday, January 2, 2014 6:58 AM, "time-nuts-request at febo.com" <time-nuts-request at febo.com> wrote:
  
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Today's Topics:

   1. Re: The Best way to Mark the New Year... (Max Robinson)
   2. Re: The Best way to Mark the New Year... (Bill Hawkins)
   3. Re: The Best way to Mark the New Year... (Glenn Little)
   4. HP 4815A vector impedance meter repair service
      (Richard (Rick) Karlquist)
   5. Measuring TV delays (Hal Murray)
   6. Re: Measuring TV delays (Bill Hawkins)
   7. Re: Measuring TV delays (David J Taylor)
   8. Re: Measuring TV delays (Mike Feher)
   9. Re: Measuring TV delays (Stanley)


----------------------------------------------------------------------

Message: 1
Date: Wed, 1 Jan 2014 11:01:52 -0600
From: "Max Robinson" <max at maxsmusicplace.com>
To: "Discussion of precise time and frequency measurement"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] The Best way to Mark the New Year...
Message-ID: <2014EB765BA74A2588DA371C79ED9CA7 at BACKROOM>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

That latency is the price we pay for digital TV.  Local analog TV only had a 
few 10s of microseconds of delay.  Network had a few milliseconds latency 
unless passed through a satellite.

Regards.

Max.  K 4 O DS.

Email: max at maxsmusicplace.com

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----- Original Message ----- 
From: "Hal Murray" <hmurray at megapathdsl.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Cc: <hmurray at megapathdsl.net>
Sent: Wednesday, January 01, 2014 5:06 AM
Subject: Re: [time-nuts] The Best way to Mark the New Year...


>
> kyrrin at bluefeathertech.com said:
>> For us, watching the rampant lunacy on "New Year's At The Needle"
>> (referring to the Seattle landmark), and chuckling at how much latency 
>> there
>> is between the local TV station's countdown and our clocks. ...
>
> Thanks for the heads up on the latency.
>
> I checked my watch before heading off to a party tonight.  My watch is 4
> seconds fast.
>
> When midnight rolled around, I watched as the whatever-it-was on the TV
> counted down.  They had a small box with a 2 digit number counting down. 
> It
> showed 18 seconds to go when my watch showed 00:04.
>
> ------
>
> Maybe next year we should see how much delay data we can collect.  That's 
> in
> addition or instead of collecting leap second data.  The usual ball drops 
> at
> local midnight so you have the time-zone offset to separate collecting
> leap-second data and midnight-TV delay data.
>
> Do any TV stations carry serious time info?  (maybe on part of the retrace
> info)
>
> I didn't check the channel or even notice where the big event was.  The 
> party I was at was in Silicon Valley.  The TV might have been showing a 
> replay from New York City, or maybe a "live" local event.
>
>
> -- 
> These are my opinions.  I hate spam.
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



------------------------------

Message: 2
Date: Wed, 1 Jan 2014 11:51:04 -0600
From: "Bill Hawkins" <bill at iaxs.net>
To: "'Discussion of precise time and frequency measurement'"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] The Best way to Mark the New Year...
Message-ID: <392AAE181DC64BA89C91262DFF4AEA69 at system072>
Content-Type: text/plain;    charset="us-ascii"

TV delays of several seconds could be due to the time delay
built into programming to avoid wardrobe malfunctions and
bad language getting on the air.

Plenty of opportunities for that when covering the public
at a New Year's Eve celebration.

Bill Hawkins



------------------------------

Message: 3
Date: Wed, 01 Jan 2014 13:26:38 -0500
From: Glenn Little <glennmaillist at bellsouth.net>
To: Discussion of precise time and frequency measurement
    <time-nuts at febo.com>
Subject: Re: [time-nuts] The Best way to Mark the New Year...
Message-ID: <mailman.3017.1388671056.2066.time-nuts at febo.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

There are a number of sources for the delay.
When I worked for a TV station, it was almost impossible to cleanly 
cut from network to local.
Network had time embedded in their signal that was constantly decoded 
by the station and displayed in master control.
The offset from local time varied, slightly, due to the digital 
encoding delays based on content.
There was the satellite delay.
Then there was the station decoding delay from network.
Then there was the encoding delay from the TV station that was 
variable based on content.
Then there was the decoding delay at the consumer TV.

We received cue tones from network to help minimize the uncertainty 
of the network to local transition.

This is part of the reason that you can see the start or end of a 
network commercial or promo that is replaced by a local commercial or promo.

I do not think that you will be able to correct or compensate 
correctly for the difference in network displayed time and true local time.

Just a little incite into some of the delays and variables involved.

73
Glenn
WB4UIV
ex CE WCIV TV


At 10:37 AM 1/1/2014, you wrote:
>From: Hal Murray
>
>Maybe next year we should see how much delay data we can collect.  That's in
>addition or instead of collecting leap second data.  The usual ball drops at
>local midnight so you have the time-zone offset to separate collecting
>leap-second data and midnight-TV delay data.
>=============================
>
>Although I've not checked it accurately, the timing clock on 
>Formula-1 races seem pretty accurate. and I've seen delays of 
>between 8 and 10 seconds when watching on Sky TV (satellite).  That 
>may also provide some useful data points without having to wait 365 
>days!  Any other sources of accurate data? I note that since 
>"digital", we no longer get a station clock at least on the channels 
>I watch - and program start times are notoriously variable!
>
>David
>--
>SatSignal Software - Quality software written to your requirements
>Web: http://www.satsignal.eu/
>Email: david-taylor at blueyonder.co.uk
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.



------------------------------

Message: 4
Date: Wed, 01 Jan 2014 15:18:46 -0800
From: "Richard (Rick) Karlquist" <richard at karlquist.com>
To: Discussion of precise time and frequency measurement
    <time-nuts at febo.com>
Subject: [time-nuts] HP 4815A vector impedance meter repair service
Message-ID: <52C4A256.6020204 at karlquist.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

FYI:

http://www.hp4815a.com/

This guy did great work for me
in 1995.  Seems to know everything
about this instrument.  Had no idea
he was still in business.

Rick Karlquist N6RK


------------------------------

Message: 5
Date: Wed, 01 Jan 2014 18:49:43 -0800
From: Hal Murray <hmurray at megapathdsl.net>
To: time-nuts at febo.com
Cc: Hal Murray <hmurray at megapathdsl.net>
Subject: [time-nuts] Measuring TV delays
Message-ID:
    <20140102024943.7A396406062 at ip-64-139-1-69.sjc.megapath.net>
Content-Type: text/plain; charset=us-ascii


Are there any events similar to New Years where some specific countdown time 
is shown on TV?

How about some show where they just show a good picture of a reliable clock?

Or do we have to wait a whole year to be able to measure things?


-- 
These are my opinions.  I hate spam.





------------------------------

Message: 6
Date: Wed, 1 Jan 2014 22:16:45 -0600
From: "Bill Hawkins" <bill at iaxs.net>
To: "'Discussion of precise time and frequency measurement'"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] Measuring TV delays
Message-ID: <77CC952267E344C1B61F06438648109A at system072>
Content-Type: text/plain;    charset="us-ascii"

Hal,

Bloomberg TV, a financial news channel, has a continuous clock in the
lower left corner.
Other financial channels may also do that, as time is of the essence.
Especially opening and closing times.

Bill Hawkins


-----Original Message-----
From: Hal Murray
Sent: Wednesday, January 01, 2014 8:50 PM

Are there any events similar to New Years where some specific countdown
time is shown on TV?

How about some show where they just show a good picture of a reliable
clock?

Or do we have to wait a whole year to be able to measure things?



------------------------------

Message: 7
Date: Thu, 2 Jan 2014 06:28:38 -0000
From: "David J Taylor" <david-taylor at blueyonder.co.uk>
To: <time-nuts at febo.com>
Subject: Re: [time-nuts] Measuring TV delays
Message-ID: <76104E8F5AE94329A2F44E13AA696DB7 at Alta>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

From: Hal Murray

Are there any events similar to New Years where some specific countdown time
is shown on TV?

How about some show where they just show a good picture of a reliable clock?

Or do we have to wait a whole year to be able to measure things?
===============================

Hal,

I already mentioned Formula 1 Motor Races (when shown live, obviously). 
Seem to be quite consistent here.

David
-- 
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu/
Email: david-taylor at blueyonder.co.uk 



------------------------------

Message: 8
Date: Thu, 2 Jan 2014 08:31:37 -0500
From: "Mike Feher" <mfeher at eozinc.com>
To: "'Discussion of precise time and frequency measurement'"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] Measuring TV delays
Message-ID: <00f301cf07be$f75c3670$e614a350$@eozinc.com>
Content-Type: text/plain;    charset="us-ascii"

Cable here had about a 10 second latency. HNY - Mike 

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell




------------------------------

Message: 9
Date: Thu, 2 Jan 2014 07:57:20 -0600
From: "Stanley" <timenuts at n4iqt.com>
To: "Discussion of precise time and frequency measurement"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] Measuring TV delays
Message-ID: <AD553024E41F4359A6F45837BC4F9A29 at StanleyPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=response

Moon Pie Drop Mobile, Alabama as watched in Birmingham 7 sec delay over the 
air, 9 sec analog cable, digital cable not checked. In fact it maybe 
possible the Satellite back feed is in the clear, something to check next 
year. Now I need a high speed multi channel CCTV setup to Capture this with 
predictable delays. Sure this will keep me busy till next year :-) Happy new 
year to all ! ( sorry for the 32 hour delay )

Stanley
----- Original Message ----- 
From: "David J Taylor" <david-taylor at blueyonder.co.uk>
To: <time-nuts at febo.com>
Sent: Thursday, January 02, 2014 12:28 AM
Subject: Re: [time-nuts] Measuring TV delays


> From: Hal Murray
>
> Are there any events similar to New Years where some specific countdown 
> time
> is shown on TV?
>
> How about some show where they just show a good picture of a reliable 
> clock?
>
> Or do we have to wait a whole year to be able to measure things?
> ===============================
>
> Hal,
>
> I already mentioned Formula 1 Motor Races (when shown live, obviously). 
> Seem to be quite consistent here.
>
> David
> -- 
> SatSignal Software - Quality software written to your requirements
> Web: http://www.satsignal.eu/
> Email: david-taylor at blueyonder.co.uk
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 



------------------------------

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