Does anyone know if there is a time when R3 broadcasts regular 'time pips',
and if so, when this is? I can't recall hearing these on R3 for some time
now, and when I've checked in recent days they weren't broadcast at
noon/1/2pm...

I'm trying to accurately measure the time offset between FM/DAB. I've
managed this for R4, but the time offset for R3 is clearly different. :-/

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

On Mon, 20 Mar 2006 15:23:13 +0000 (GMT), Jim Lesurf
wrote:

Does anyone know if there is a time when R3 broadcasts regular 'time pips',
and if so, when this is? I can't recall hearing these on R3 for some time
now, and when I've checked in recent days they weren't broadcast at
noon/1/2pm...

I'm trying to accurately measure the time offset between FM/DAB. I've
managed this for R4, but the time offset for R3 is clearly different. :-/

Slainte,

Jim

A long time now since I last heard the pips on R3. Unless they are
doing it at some outlandish hour, I'm pretty sure they don't bother
any more.

As for R4, are you finding that the offset is consistent, or does it
change during the day as they change bit rate?

d

Pearce Consulting
http://www.pearce.uk.com

In article , Don Pearce
wrote:


As for R4, are you finding that the offset is consistent, or does it
change during the day as they change bit rate?

Not determined as yet, but I suspect that the DAB/FM time offset *does*
vary with bitrates, etc. The problem is that it is quite difficult to
determine this accurately with 'normal' speech and music. Ideally, I'd like
to determine the time alignment to the order of 1 sample interval at
44.1ks/sec, but so far I've only got close to this for R4 using the pips.
With R3 it becomes hard to determine this closer than a few milliseconds.

My 'best estimates' so far are 1.368 sec for R3 and 1.344 sec for R3, (R4
at 128kb/s and R3 at 192kb/s - although of course the rates of all the
other stations on the MUX may affect this.) For the data I have so far the
R4 value seems more reliable.

Alas, my main interest is in R3, not R4...

I suspect it may also vary across the UK due to differences in distribution
deplays. Also probably from one DAB tuner to another due to different
decoding process timings... :-)

The values I have at the moment are OK for some purposes, but not accurate
enough for some of the analysis I'd like to try.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article ,
Jim Lesurf wrote:
I suspect it may also vary across the UK due to differences in
distribution deplays. Also probably from one DAB tuner to another due to
different decoding process timings... :-)


I've only got one DAB receiver but 5 FreeView ones. If you have those on
at the same time throughout the house on the same channel you can clearly
hear different delays. And that's without my DLP rear projector which adds
its own delay to the sound to sync up with the picture. ;-)

--
*Prepositions are not words to end sentences with *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
wrote:
In article , Jim Lesurf
wrote:
I suspect it may also vary across the UK due to differences in
distribution deplays. Also probably from one DAB tuner to another due
to different decoding process timings... :-)


I've only got one DAB receiver but 5 FreeView ones. If you have those on
at the same time throughout the house on the same channel you can
clearly hear different delays.

Alas, this does not surprise me. :-/ The time offset between DTTV and DAB
is quite marked for the RXs I have. All very annoying when you want to make
measured comparisons as it means having to realign the data.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article ,
Jim Lesurf wrote:
I've only got one DAB receiver but 5 FreeView ones. If you have those
on at the same time throughout the house on the same channel you can
clearly hear different delays.

Alas, this does not surprise me. :-/ The time offset between DTTV and
DAB is quite marked for the RXs I have. All very annoying when you want
to make measured comparisons as it means having to realign the data.

Sorry - I meant between different DTTV receivers. Of course the difference
between them isn't as great as the delay between FM, DAB and DTTV all
listened to at the same time, but still obvious. A sort of 'flutter'.

--
*No sentence fragments *

Dave Plowman London SW
To e-mail, change noise into sound.

On 2006-03-20, Jim Lesurf wrote:
Does anyone know if there is a time when R3 broadcasts regular 'time pips',
and if so, when this is? I can't recall hearing these on R3 for some time
now, and when I've checked in recent days they weren't broadcast at
noon/1/2pm...

Reliably at 07:00 (when I used to get up at 06:30 which was until fairly
recently). I could hear the FM pips from the bedside clock/radio and the
DAB pips from the kit in the lounge. I'm not sure if that has changed
in the last couple of months (07:15 wake-up now).

I have some recordings I made for level calibration purposes. The amount
of LF rubbish that is present during the last pip, after they have opened
the mic. in continuity, is quite depressing.

--
John Phillips

I have some recordings I made for level calibration purposes. The amount
of LF rubbish that is present during the last pip, after they have opened
the mic. in continuity, is quite depressing.

So I'm not the only one who's noticed this.. shameful for the BBC....
--
Tony Sayer

In article , John Phillips
wrote:
On 2006-03-20, Jim Lesurf wrote:
Does anyone know if there is a time when R3 broadcasts regular 'time
pips', and if so, when this is? I can't recall hearing these on R3 for
some time now, and when I've checked in recent days they weren't
broadcast at noon/1/2pm...

Reliably at 07:00 (when I used to get up at 06:30 which was until fairly
recently). I could hear the FM pips from the bedside clock/radio and
the DAB pips from the kit in the lounge. I'm not sure if that has
changed in the last couple of months (07:15 wake-up now).

Blast! The chance of my being awake enough to do any useful recordings that
time in the morning is close enough to zero to use it as a definition of
the term. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html