All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Chris: ITV4 isn't the same as Channel 4. I think a little potted history lesson is necessary.
In 1955, "ITV" started up, which is a group of regional operators such as Granada, Meridian, Yorkshire etc. Over the years, the regional operators have been bought and now those in England and Wales are all owned by the same company, ITV Plc. Today it uses the "ITV1" wallpaper for its network of regional stations. I'll come on to why the "1" has been added.
In 1982, the fourth television service was launched in the UK. For everywhere except Wales, it was Channel 4. Wales got its own fourth service, S4C.
The introduction of the digital system ("Freeview") means that more channels can be broadcast. This has lead to the BBC, ITV Plc, Channel 4 and others introducing other channels.
The BBC started up BBC Three and BBC Four, ITV Plc has ITV2, ITV3 and ITV4 and Channel 4 has E4, More 4, 4Music and Film4. The "1" on ITV has been introduced due to the other three ITV Plc services being in operation.
Because the Freeview system can carry more channels, Channel 4 can now be broadcast Wales, as well as S4C. Because button number 4 is used in Wales by S4C, Channel 4 is on button 8 in Wales.
The transmitter called "Aberdare" is on the hill to the east of Cwmbach. See here for a map of the location:
Bing Maps - Driving Directions, Traffic and Road Conditions
And here for photographs:
mb21 - The Transmission Gallery
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Dennis: No because there are only a handful of ITV1HD regions (four or five, I believe).
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Beryl Gray: Yesterday is one of the channels that is not available on Freesat, but is available on the full Freeview service. As you are in an area served by full Freeview now, then you will be after switchover.
Yesterday is not available on analogue and has never been. Terrestrial analogue consists of BBC One, BBC Two, ITV and Channel 4. Channel 5 is available on analogue with limited coverage.
As you TV is likely to have Freeview built in, or you have a separate Freeview box if it doesn't, then you would be best advised to retain it and the terrestrial aerial as a back-up should the satellite services be unavailable and also so you can view channels that aren't available on Freesat.
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S Williams: Try running the automatic tuning scan with the aerial unplugged up until 63%. You may have to manually add C48 for ITV3 etc.
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Grant Buckley: Your reply has confirmed that all channels are tuned correctly to the same transmitter, Emley Moor.
As you have found, digital broadcasts carry a number of services as part of the same signal. That is you get a basket of programme channels on one frequency known as a multiplex. The six I listed above are each part of a different multiplex.
When did this problem begin?
Have you tried changing the aerial lead from the wall to the TV? Is it short?
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Stuart O.: As a guess, I would say that the significance of 24th October is that it is the date the the whole of Ireland switches to digital TV. I wonder, therefore, whether "reactive power" means that the power might be reduced should the signal travel further than normal and interfere with other services on channel 48.
The mention of 12.5kW is perhaps the figure that was quoted by official sources such as Ofcom at the time it was written. As I say, if you refer to the latest Ofcom document, it says 10kW for the COMs, so this would appear to be the current value.
Perhaps one of the pros could shed more light on this and whether my guess might be right.
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Paul: The current "digital switchover" is for terrestrial television only. It has nothing to do with radio and nothing to do with DAB.
The design of some receivers leaves a lot to be desired. This is not specifically confined to the "cheapo" sets.
There will always be instances where signals from adjacent transmitters overlap. Some boxes just go with the first one they find.
Transmitters do broadcast their "Network" name, but not all receivers display it. However, most receivers display the UHF channel that is being received and this information is usually given on the signal strength screen.
In some cases where incorrect transmitter(s) are being picked up, it's possible to remove the aerial lead for part of the scan to get it to do what you want it to do.
It is possible to do this with the caveat that you will have to manually add a couple as they are mixed in with those of Heathfield.
Midhurst's channels are 55, 61, 58 (HD), 62, 59, 50
Heathfield's are 29 to 54 now and 41 to 52 after its DSO.
So, if your receiver shows UHF channel numbers when it's scanning, start it off with the lead unplugged and connect it after it's scanned 54 to avoid Heathfield. You will then need to manually add 50 (Yesterday etc) and probably 55 (BBC standard definition services).
If your receiver doesn't give channel numbers, but only a percentage, then the scan is likely to be from channels 21 to 69, so plug in around 71%. Then manually add 50 and 55 as explained above.
Whilst this may be clumbersome, it might be more attractive than letting it put Midhurst in the 800s and you having to swap each one.
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Peter: Some receivers, having performed the automatic tuning scan, will ask the user to choose the "Network" or "Region". This is in fact selection of which transmitter to go with. It is therefore important to ensure that the correct one is selected and that the default should not necessarily be chosen (which could be the first one in alphabetically).
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Saturday 17 March 2012 12:05PM
Grant Buckley: Looking at the location and the fact that your aerial is, one assumes, on the top of the six storey block, you should not have any issues with signal strength.
Where a communal aerial system is provided, then the signal should be the appropriate level when it comes out of the wall socket. If it's not, then it is the operator's responsibility. The operator is probably the landlord.
However, the first thing to check is that the your receiver is tuned to the signals from the transmitter to which the aerial faces. The height of the aerial makes it very likely to be receptive to signals from other (which the aerial does not face).
Which programme channels show low signal strength and drop-out?
Also, for each of the following, go to the signal strength screen and let us know which UHF channel it is tuned to. Receivers usually give this information, although not always.
BBC One (probably channel 24 or 47)
ITV1 (probably channel 21 or 44)
BBC One HD (if applicable) (probably channel 27 or 41)
ITV3 (probably 42 or 51)
Pick TV (probably 45 or 52)
Yesterday (probably 39 or 48).