On 29/02/2024 19:36, John Williamson wrote:
> On 29/02/2024 14:59, Mike Headon wrote:

>> They used to say that radio listeners in Australia heard the chime of
>> Big Ben before someone outdoors in Lambeth!
>
> Marginal. If you stand on the South Bank next to Westminster Bridge, the
> speed of sound delay is about 750 milliseconds.
>
> Transmission delay to and from geostationary orbit is about half a
> second plus landline delay at each end, not forgetting that at least two
> satellites are involved due to imitations of coverage. Using landline
> all the way is even slower. You may do slightly better using the
> Starlink constellation, which are all in very low orbits and can link
> with each other, with a ping time to a ground station of about 50 ms.

Vicki Pipe (of Geoff Marshall and Vicki Pipe "All the Stations" fame, in
which they travelled to every railway station in the UK) did a test in
which she stood on Westminster Bridge with an FM (not digital) radio
that was tuned to Radio 4. When the Big Ben chimes preceded the 6 PM
news, you could hear the first bong through the radio noticeably before
the sound of it reached the camera's microphone through the air. I
measured the time difference and concluded that she was about 70 metres
away.

https://www.youtube.com/watch?v=5dwUWtyRP4c

In article <urpch5$dk50$1@dont-email.me>, Tweed <usenet.tweed@gmail.com>
scribeth thus
>tony sayer <tony@bancom.co.uk> wrote:
>> In article <l48p8jFtj3iU1@mid.individual.net>, Mark Carver
>> <mark@invalid.com> scribeth thus
>>> On 28/02/2024 12:17, Clive Page wrote:
>>>> On 13/02/2024 19:17, Brian Gaff wrote:
>>>>> Yes well they were stopped some time back and I think are generated by
>>>>> the
>>>>> bbc themselves with a countdown up to them to aid program producers. So I
>>>>> wonder if there was some way that the delay could be accounted for on the
>>>>> different media delivery systems. I'd imagine if a sat were involved it
>>>>> would be the longest delay. However D
>>>>> aB and internet can be worse sometimes but it seems to vary.
>>>>>   Brian
>>>>
>>>> The programme which prompted this thread was, I thought, not really very
>>>> good, and almost totally lacking in technical detail.   Like nearly all
>>>> BBC programmes it was, I guess, produced by graduates in "media studies"
>>>> or something like that.
>>>>
>>>> About the only detail that was new to me was the claim than at midnight
>>>> on a date when a leap second was introduced there would be 7 pips.   But
>>>> I don't know of any BBC programme that uses pips at midnight - it always
>>>> seems to be the chimes of Big Ben.
>>>>
>>>> There was nothing about this in the programme, but I'm vaguely remember
>>>> hearing many years ago that the BBC used to adjust the timing of the
>>>> pips so that a typical listener in the home counties, say 50 km from a
>>>> London area transmitter like Wrotham, would get the most accurate
>>>> signal.  Anyone living nearer the transmitter than that would get a time
>>>> signal a fraction of a millisecond early, those in more distant parts of
>>>> the UK would necessarily get it a few milliseconds late, but there
>>>> really wasn't much they could do about that at reasonable cost.   Does
>>>> anyone else remember that or is my memory playing tricks?
>>>>
>>>>
>>> A far more significant factor, is how far away you are from the radio's
>>> loudspeaker !
>>
>> A far more important factor is how many females there are there who have
>> clocks from five to ten minutes fast, or slow even, known that!..
>>
>> If you want it "that" accurate Rubidium standards are on fleabay from
>> time to time;!..
>>
>
>Rubidium standards don’t tell the time.
>

No course not my mistake! accurate frequency is more important to me !
For which i have a Leo Bodnar GPS frequency standard works very well and
you can output whatever frequency you want from it:)..

https://www.leobodnar.com/shop/index.php?main_page=index&cPath=107

--
Tony Sayer

Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

On Fri 01/03/2024 11:04, tony sayer wrote:
> In article <urpch5$dk50$1@dont-email.me>, Tweed <usenet.tweed@gmail.com>
> scribeth thus
>> tony sayer <tony@bancom.co.uk> wrote:
>>> In article <l48p8jFtj3iU1@mid.individual.net>, Mark Carver
>>> <mark@invalid.com> scribeth thus
>>>> On 28/02/2024 12:17, Clive Page wrote:
>>>>> On 13/02/2024 19:17, Brian Gaff wrote:
>>>>>> Yes well they were stopped some time back and I think are generated by
>>>>>> the
>>>>>> bbc themselves with a countdown up to them to aid program producers. So I
>>>>>> wonder if there was some way that the delay could be accounted for on the
>>>>>> different media delivery systems. I'd imagine if a sat were involved it
>>>>>> would be the longest delay. However D
>>>>>> aB and internet can be worse sometimes but it seems to vary.
>>>>>>   Brian
>>>>>
>>>>> The programme which prompted this thread was, I thought, not really very
>>>>> good, and almost totally lacking in technical detail.   Like nearly all
>>>>> BBC programmes it was, I guess, produced by graduates in "media studies"
>>>>> or something like that.
>>>>>
>>>>> About the only detail that was new to me was the claim than at midnight
>>>>> on a date when a leap second was introduced there would be 7 pips.   But
>>>>> I don't know of any BBC programme that uses pips at midnight - it always
>>>>> seems to be the chimes of Big Ben.
>>>>>
>>>>> There was nothing about this in the programme, but I'm vaguely remember
>>>>> hearing many years ago that the BBC used to adjust the timing of the
>>>>> pips so that a typical listener in the home counties, say 50 km from a
>>>>> London area transmitter like Wrotham, would get the most accurate
>>>>> signal.  Anyone living nearer the transmitter than that would get a time
>>>>> signal a fraction of a millisecond early, those in more distant parts of
>>>>> the UK would necessarily get it a few milliseconds late, but there
>>>>> really wasn't much they could do about that at reasonable cost.   Does
>>>>> anyone else remember that or is my memory playing tricks?
>>>>>
>>>>>
>>>> A far more significant factor, is how far away you are from the radio's
>>>> loudspeaker !
>>>
>>> A far more important factor is how many females there are there who have
>>> clocks from five to ten minutes fast, or slow even, known that!..
>>>
>>> If you want it "that" accurate Rubidium standards are on fleabay from
>>> time to time;!..
>>>
>>
>> Rubidium standards don’t tell the time.
>>
>
> No course not my mistake! accurate frequency is more important to me !
> For which i have a Leo Bodnar GPS frequency standard works very well and
> you can output whatever frequency you want from it:)..
>
>
> https://www.leobodnar.com/shop/index.php?main_page=index&cPath=107
>

+1 - a superb piece of kit and good value for money (well it was at £98
when I got mine!)

tony sayer wrote:

> i have a Leo Bodnar GPS frequency standard works very well and
> you can output whatever frequency you want from it:)..
>
> https://www.leobodnar.com/shop/index.php?main_page=index&cPath=107

I recognise where standard clocks like 32.768 kHz or 3.579545 MHz come
from, but what is significant about 49.152 MHz ?