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, "[email protected]" <[email protected]> wrote: Send time-nuts mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." 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" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Subject: Re: [time-nuts] The Best way to Mark the New Year... Message-ID: <2014EB765BA74A2588DA371C79ED9CA7@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: [email protected] Transistor site http://www.funwithtransistors.net/ Vacuum tube site: http://www.funwithtubes.net/ Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com/ To subscribe to the fun with transistors group send an email to. [email protected] To subscribe to the fun with tubes group send an email to, [email protected] To subscribe to the fun with wood group send a blank email to [email protected] ----- Original Message ----- From: "Hal Murray" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Cc: <[email protected]> Sent: Wednesday, January 01, 2014 5:06 AM Subject: Re: [time-nuts] The Best way to Mark the New Year... > > [email protected] 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 -- [email protected] > 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" <[email protected]> To: "'Discussion of precise time and frequency measurement'" <[email protected]> Subject: Re: [time-nuts] The Best way to Mark the New Year... Message-ID: <392AAE181DC64BA89C91262DFF4AEA69@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 <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] The Best way to Mark the New Year... Message-ID: <[email protected]> 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: [email protected] >_______________________________________________ >time-nuts mailing list -- [email protected] >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" <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: [time-nuts] HP 4815A vector impedance meter repair service Message-ID: <[email protected]> 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 <[email protected]> To: [email protected] Cc: Hal Murray <[email protected]> Subject: [time-nuts] Measuring TV delays Message-ID: <[email protected]> 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" <[email protected]> To: "'Discussion of precise time and frequency measurement'" <[email protected]> Subject: Re: [time-nuts] Measuring TV delays Message-ID: <77CC952267E344C1B61F06438648109A@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" <[email protected]> To: <[email protected]> Subject: Re: [time-nuts] Measuring TV delays Message-ID: <76104E8F5AE94329A2F44E13AA696DB7@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: [email protected] ------------------------------ Message: 8 Date: Thu, 2 Jan 2014 08:31:37 -0500 From: "Mike Feher" <[email protected]> To: "'Discussion of precise time and frequency measurement'" <[email protected]> Subject: Re: [time-nuts] Measuring TV delays Message-ID: <[email protected]> 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" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Subject: Re: [time-nuts] Measuring TV delays Message-ID: <AD553024E41F4359A6F45837BC4F9A29@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" <[email protected]> To: <[email protected]> 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: [email protected] > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ------------------------------ _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 114, Issue 3 ***************************************** _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
