RTE NL Test Channel Clock

SRB

I'm curious about the clock on the RTENL test card - it's just over 2 and 1/2 minutes out from time of day - now obviously there are delays introduced by the various encoding stages - BBC1 Analogue is about 4 seconds ahead of BBC1 Digital and that's now taken as "normal", but 2 and 1/2 minutes ?

The Cush

Just checked it against my MSF watch, it appears to be 1 min 33sec behind.

SRB

Opps, yes, it's 1.33 with me too, not 2.33 - still quite a delay.

The Cush

The delay is quiet noticeable when you are watching analogue and digital terrestrial on different tv's in the house.

SRB

True, though mostly it's a few seconds.

pa990

i noticed that too.. the EPG time at the top of the screen is about 2 min faster than the test card clock..
i didn't calculate exactly the time difference.. so it could be 1:33 or 2:33.

i didnt spend too much time watching it any way

SRB

Ah - now if it was showing a different delay at two different sites, then that would be interesting !

The Cush

There was a similar discussion over in DigitalSpy last year Why is Freeview 4 seconds behind analogue

Something I read in the past said that 2 analogue tvs beside each other will display the same picture without delay or difference but two digital tvs beside each other displaying the same programme a difference can be noticed due to the processing technology in the tvs.

This from the BBC

Why is there a time delay of a second or two between digital and analogue broadcasts?

The delay is due to the digital and analogue signals being broadcast in different ways. Digital signals have to be compressed before being transmitted and then uncompressed by your receiver before being turned into sound or pictures. This process causes the slight delay.

Buffering: Another issue that may arise only with digital TV is what is referred to as preload delay till the set buffer enough content to begin showing the broadcast stream. This delay varies between different TV sets and leads to a significant delay - in comparison to the almost instant response associated with an analog TV - when changing channels. This delay can make 'channel surfing' on digital television sets more difficult.

http://www.practical-home-theater-guide.com/digital-tv.html

Digital time lag, time signals and delays on TV and radio

L1011

The digital delay doesn't add up to 1 minute, 33 seconds though - the master clock is clearly just set wrong.

Gerry Wicklow

MYOB wrote: »

The digital delay doesn't add up to 1 minute, 33 seconds though - the master clock is clearly just set wrong.

Given that the EPG is quite inacurate as well its only to be expected.
It IS only a test after all.

SRB

Well yes, but while the EPG has always been like that since it appeared, someone went to the bother of recently enabling the clock, or maybe it was an accident, lol.
"Damn, how do I get this off again ? Double Damn, I can't get it off and I can't set it either - right if anyone notices I'll change back to the bars....."

Alun

MYOB wrote: »

The digital delay doesn't add up to 1 minute, 33 seconds though - the master clock is clearly just set wrong.

Maybe it's the same clock they use for their RDS service .. the clock on that is off by about the same amount as well.

L1011

Would be interested to know what, and where, that clock is. Theres Patek Phillipe precision timing units sitting unused in a room in the new Belfast RTE radio studios, or at least there was last year!

SRB

Why thank you for fixing the clock !
Allowing for the "coding and muxing" 5 secs delay is around what I would have expected - hence the original post.
(Though some would argue it should be offset at source to account for the delay)
Oh and while someone is "out there" reading these posts - any chance of upping the resolution on the other channels again ?

L1011

SRB wrote: »

Oh and while someone is "out there" reading these posts - any chance of upping the resolution on the other channels again ?

I think RTENL engineers drop in here from time to time, any time the DAB sync has drifted to make it unlistenable at home it never gets fixed till I whinge on this forum

marclt

Now, if only those engineers would stop lurking and maybe give us some 'leaks' once in a while!

If only they could up the power on Mt. Leinster Ch. 39! I'd be very happy!!!!

PyeContinental

Up on 39, off on the others please!

lucernarian

You can up Ch. 39 all ye like, but if that's the cause of my loss of Analogue BBC1 from Kilkeel in recent months, I will not be so supportive:pac:

exaisle

MYOB wrote: »

I think RTENL engineers drop in here from time to time, any time the DAB sync has drifted to make it unlistenable at home it never gets fixed till I whinge on this forum

When Lyric FM became noisy from Kippure last summer, I whinged here, contacted RTE and whinged some more....for all the good it did me, because it took them ages to fix it......

Alun

Alun wrote: »

Maybe it's the same clock they use for their RDS service .. the clock on that is off by about the same amount as well.

Well surprise, surprise, RDS clock is OK now too