Time on the radio

[Prudie]

I listen to radio upstairs on a normal analogue radio and often have it on a digital downstairs at the same time. The DAB is about 2 seconds behind the analogue, particularly noticeable when the pips play - so when we switch to all digital will we permanently lose 2 seconds of our time and will the digital time always be a bit late? Do you get what I mean?

[albaqwerty]

I understand what you mean. Some msybe all radio stations) transmit some seconds behind real time so they can bleep out sweary words etc

[seadogg]

A DAB signal has to be compressed at the transmitting end and decompressed by the receiver so it takes longer. If you wish to set a watch etc use analogue but when analogue radio is phased out there will probably be some form of compensation to allow yo to hear the pips at the correct time.

[Buenchico]

The BBC time signals are taken from the National Physical Laboratory. At the moment there's no way to allow for the processing delays of DAB but, once the FM transmitters are turned off, it's possible that the BBC could use an adjusted signal so that everyone heard the correct time on DAB. However that would result in the Long Wave and Medium Wave transmissions having a time signal which was slightly too early, so I doubt that any changes would be immediate. (There are currently no plans to switch off the LW & MW transmitters).

Further, Radio 4 still uses Big Ben for some time signals. (No, it's not a recording. There really is a microphone in the tower!). Unless the BBC broke with tradition, and switched to using a recording of the chimes, either Big Ben would have to be set incorrectly or we'd still have a time signal which was too late on DAB!

Chris

[Prudie]

I am talking R4 as it happens and you have just compounded my point Chris

[Tim123]

The DAB version has to be digitally compressed then multiplexed with other services before it can be broadcast. This process takes an appreciable amount of time. The demultiplexing and decompressing in your radio takes time as well, but not as much. The delay is nothing compared to that for an HD televison service, which in excess of 10 seconds.

[scotman]

Interesting question, I imagine it would be possible to have 2 sets of pips; one for DAB and the other for analogue. Probably do away with the microphone in the tower.

[Buenchico]

You could have two sets of pips, Scotman, but you'd need to have a couple of seconds of silence built into the programming in order to accommodate them both.

[scotman]

Only if you were transmitting the same programme on both. Anyway, who needs to know the time that accurately anyway.

[Prudie]

Err perfectionists, control freaks, special agents setting their watches :-)

[mibn2cweus]

. . . In that case, don't neglect to set you watch forward an additional millisecond for each foot away you are from the speaker.

[chakka35]

There is no need to mess around with the Westminster clock. The radio-controlled clock on my kitchen wall (accurate to a second in a million years, though I haven't had enough time to check that yet) tells me the exact time, against which I can check both Big Ben's strikes (rarely more than a second out) and the pips.
Before you suggest it, I do have a life, thanks.

[rov1100]

With Sky the signal has to travel to the satelite and back which takes time. With terrestrial transmission its a lot quicker. So you could get large gaps if you happen to be listening to one of the radio staions on either media.