I often listen to the BBC through the Internet via a smart speaker and the
latency is comically bad -- something like 10 or 15 seconds. It makes sense
to me that they'd want to retire the pips given not just the ubiquity of
alternate accurate time sources, but the pips are very wrong when the BBC
is received using modern methods.

I'm less bothered by an announcer saying "It's the top of the hour",
because the implied accuracy of such a statement is on the same order of
the actual accuracy of ~10 seconds. The pips, though, give the illusion of
sub-second accuracy when the reality is 100x worse.

Of course, the pips score high on nostalgia so I still vote to keep them in
:)

On Thu, Feb 1, 2024 at 9:31 PM Hal Murray via time-nuts <
time-nuts@lists.febo.com> wrote:

Yes, but it was several decades ago when GPS for the masses was quite new
and I had just bought a Garmin GPS25 module.
On the 198kHz AM prog the pips were within hundreds of microseconds of GPS
PPS, a delay commensurate with the bandwidth of the IF filter in
the receiver.

But on VHF they were 3 milliseconds late.  In jest I wrote to  Terry Wogon
the then presenter of the morning show on Radio 4 (non UK leaders may
gloss over this bit :-) to point this out and say that cumulatively this
lateness of the 'pips' made me several seconds late for work over the
year.  It never got a mention on his  prog though.

Andy
www.g4jnt.com

On Fri, 2 Feb 2024 at 05:31, Hal Murray via time-nuts <
time-nuts@lists.febo.com> wrote:

It's about 3.3 µs per kilometer and VHF-transmitters have a shorter range, so you're likely to listen to a local transmitter. However, often these are coupled to the main transmitter with digital lines. In this country the link has been digital since the early eighties of the last century. The AD, transmission and DA of the signal introduces another source of latency.

For me, the AM pips were 150µs late, and the FM pips were 1150µs late. Even though I could almost see the FM transmitter and the AM transmitter is in the center of the country, ~100km away.

As you noted, buffering delays for streaming services can be significant and occur on all legs of the journey from source to your ear. Several minutes is not uncommon.

--

Ruben

and there is OFDM SFN sync delay

On 3/02/2024 2:38 am, Rsec Van der leij via time-nuts wrote: