[time-nuts] US New Year countdown - accurate?

Javier Herrero jherrero at hvsistemas.es
Mon Jan 2 18:48:22 EST 2012


El 02/01/2012 23:33, Magnus Danielson escribió:
>
> The small TV set in the kitchen might be CRT while the big one in the 
> living room is LCD (or any similar flat screen), and for the later 
> double-buffering (or more) is employed as standard. These new screens 
> are "slow" and create tons of artefact with standard definition TV or 
> just the wrong rate.
>
In the transition time between analog and digital TV in Spain, I had an 
analog TV at the kitchen and a digital LCD at the living room. Both 
transmissions were from the same site, but the audio and video delay in 
the digital one with respect to the analog was in the order of two 
seconds. I suppose that part is on the TV, but the bigger delay is in 
the transmission side :) Now, analog TV is gone, so no opportunity to 
repeat the experiment.

Long time ago (~25yr), I had a friend working at Torrespaña, that is the 
production and transmission center for the spanish national television, 
TVE. Since I was a latent time nut then, I was interested on the 
different timing systems, and he show them to me. Time distribution, for 
teletext and for the clock that was shown at 3pm and 9pm during a few 
seconds just before the news, was taken by a time distribution system 
provided by Union Relojera Suiza (Swiss Clockwork Union or something 
like that), and I don't remember exactly but I think that the time for 
that system was taken from a leased line from ROA (the Real Observatory 
of Spain at San Fernando, Cadiz, the official timekeepers and UTC 
contributors at Spain), so it was a quite good time. Synchronisms were 
generated from a HP 5061 Cs, and chroma burst was generated by a HP 5065 
Rb.

Around 7 yr ago, I gave a friend a GPS driven nixie clock, and he had 
fun taken a picture in which you can see that the second changes 
simultaneously in the TVE teletext clock and the nixie clock (both in 
screen and at the clock the second digits were superimposed), so it 
seems that the discrepancy is inside an aperture time (probably 1/125 - 
he was not using any special technique). He lives 2-3km from Torrespaña, 
so the delay due to propagation is in the microsecond range.

 From 50yr ago, in Spain a lot of people celebrates the new year with 
the TVE transmission of the clock located at Puerta del Sol in Madrid, 
in the center of Spain (in fact, Km 0 for the six main radial roads 
starting from Madrid), and customarily people takes twelve grapes, one 
at each gong of the clock. I know that it is 50yr because this year they 
were celebrating the 50 anniversary of the first transmission of the 
event :) Now, I know that people celebrates new year with at least 2 
second delay thanks to DTV progress :)

(In my case, from long ago, I'm out of Spain for new year, at the place 
where the local people celebrates the event - this year, Rathaus 
building clock in Vienna :) )

A bit late, but happy new year to all!!!!

Regards,

Javier





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