TV
I've read that about eight times and I now understand it -- ta for that.
The first bit is what I was meaning, but was far too rubbish to know how to express.
I had wondered why, if the analogue feed was *always* going through Cardiff, there was no longer the one second delay compared to Mendip/Winter Hill [only two I can comment on] after closedown, as there was during the day.
Mind you S4C don't seem to care about the various digital/analogue delays around -- still continuing to use their clock. Especially when it says 20:42:45 or something equally as useless.
Steve D posted:
No, the 'click' - which is only on the analogue chain - is because after closedown the analogue chain is switched to sustain on the analogue network feed from London. This is the only time BBC Wales viewers get a feed of analogue network, as from 6am until closedown both transmission chains sustain on the digital network.
Both the analogue and digital signal paths ALWAYS go via Cardiff. Even after closedown the network feeds of both digital and analogue networks come from TVC to BH Cardiff, from where they're distributed to the transmitter chain via Wenvoe, or in the case of DSat back to TVC and on to the uplink.
During the day, because digital and analogue chains are sustained from the same network, you don't get a 'click' on the analogue chain when the Cardiff pres suite goes out of circuit - in fact it's seamless.
Both the analogue and digital signal paths ALWAYS go via Cardiff. Even after closedown the network feeds of both digital and analogue networks come from TVC to BH Cardiff, from where they're distributed to the transmitter chain via Wenvoe, or in the case of DSat back to TVC and on to the uplink.
During the day, because digital and analogue chains are sustained from the same network, you don't get a 'click' on the analogue chain when the Cardiff pres suite goes out of circuit - in fact it's seamless.
I've read that about eight times and I now understand it -- ta for that.
The first bit is what I was meaning, but was far too rubbish to know how to express.
I had wondered why, if the analogue feed was *always* going through Cardiff, there was no longer the one second delay compared to Mendip/Winter Hill [only two I can comment on] after closedown, as there was during the day.
Mind you S4C don't seem to care about the various digital/analogue delays around -- still continuing to use their clock. Especially when it says 20:42:45 or something equally as useless.
SP
I'd guess that Fox take Hit 40 UK directly off the main feed from one of IRN's SMS satellite channels.Horizon probably take it off the GWR network show feed which will include automated signals to play local idents. This will have an extra delay as it has to be sent via a second (GWR's) satellite feed.
(Just guesswork based on what I know about other radio groups systems - so feel free to correct me!)
russnet posted:
When I listen to the Hit 40 UK (for all my sins) on FOX FM. It is a good second or two ahead of my other local ILR station of Horizon Radio.
I'd guess that Fox take Hit 40 UK directly off the main feed from one of IRN's SMS satellite channels.Horizon probably take it off the GWR network show feed which will include automated signals to play local idents. This will have an extra delay as it has to be sent via a second (GWR's) satellite feed.
(Just guesswork based on what I know about other radio groups systems - so feel free to correct me!)
SP
Sput
Uncle Bruce posted:
I'd have thought that was obvious.
Half a second to transmit, another half a second to encode into MPEG.
Wait a second! Isn't that what I said at the start of this thread?! Honestly, the attention span of some people. Thankfully mine is long enough that I know exactly what rocket science is, what with reading a masters in it and all...
LL
I'd guess that Fox take Hit 40 UK directly off the main feed from one of IRN's SMS satellite channels.Horizon probably take it off the GWR network show feed which will include automated signals to play local idents. This will have an extra delay as it has to be sent via a second (GWR's) satellite feed.
(Just guesswork based on what I know about other radio groups systems - so feel free to correct me!)
That is right, Horizon and other GWR stations switch to the network feed from Bristol at 4pm on Sunday which means there is a slight delay with Hit 40 UK being routed from London to Bristol, then back to the station. It's easier for GWR stations to do this as they all take network programming from 4pm to 6am on Sun/Mon.
London Lite
Founding member
Spencer For Hire posted:
russnet posted:
When I listen to the Hit 40 UK (for all my sins) on FOX FM. It is a good second or two ahead of my other local ILR station of Horizon Radio.
I'd guess that Fox take Hit 40 UK directly off the main feed from one of IRN's SMS satellite channels.Horizon probably take it off the GWR network show feed which will include automated signals to play local idents. This will have an extra delay as it has to be sent via a second (GWR's) satellite feed.
(Just guesswork based on what I know about other radio groups systems - so feel free to correct me!)
That is right, Horizon and other GWR stations switch to the network feed from Bristol at 4pm on Sunday which means there is a slight delay with Hit 40 UK being routed from London to Bristol, then back to the station. It's easier for GWR stations to do this as they all take network programming from 4pm to 6am on Sun/Mon.
UB
I'd have thought that was obvious.
Half a second to transmit, another half a second to encode into MPEG.
Wait a second! Isn't that what I said at the start of this thread?! Honestly, the attention span of some people. Thankfully mine is long enough that I know exactly what rocket science is, what with reading a masters in it and all...
It just seems that the children don't understand unless ... you ... speak ... very ... s l o w l y
Sput posted:
Uncle Bruce posted:
I'd have thought that was obvious.
Half a second to transmit, another half a second to encode into MPEG.
Wait a second! Isn't that what I said at the start of this thread?! Honestly, the attention span of some people. Thankfully mine is long enough that I know exactly what rocket science is, what with reading a masters in it and all...
It just seems that the children don't understand unless ... you ... speak ... very ... s l o w l y
CS
So does that mean N24 runs 2-5 seconds ahead of BST? to counteract the digital delay?
UB
Yes, we're speaking ... very ... s l o w l y ... today
Cerulean Sunrise posted:
So does that mean N24 runs 2-5 seconds ahead of BST? to counteract the digital delay?
Yes, we're speaking ... very ... s l o w l y ... today
MS
It should be the case that 5Live on DSat is the same as MW - the MW transmission goes through a delay stage so that it's in synch with the satellite transmission so that if a transmitter loses its feed it can fail to the digibox backup without causing problems in the overlap areas where there are two transmitters on the same frequency.
Not having been mativated enough to test it, I've seen suggestions that C4 do much the same, for the same reasons.
Steve in Pudsey posted:
It should be the case that 5Live on DSat is the same as MW - the MW transmission goes through a delay stage so that it's in synch with the satellite transmission so that if a transmitter loses its feed it can fail to the digibox backup without causing problems in the overlap areas where there are two transmitters on the same frequency.
Not having been mativated enough to test it, I've seen suggestions that C4 do much the same, for the same reasons.