All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Anne Kimber: No, the number of channels available from relays such as Modbury are not likely to increase.
This is because the Commercial networks that don't broadcast from these transmitters achieve coverage of about 90% of the population from 81 of the largest transmitters (largest by viewer population).
There are over 1,000 small "filler-in" relays like Modbury that serve about 8.5% of the population. For the Commercial networks to broadcast from them would roughly double their cost of transmission as the cost to transmit from the relays is about equal to that of the 81 main transmitters.
As the Commercial networks are run purely for profit and have no obligation to provide a public service, they are allowed to make their own decisions as to where they serve.
They show adverts to as many viewers as possible which they wish to acquire at lowest possible cost. Accordingly they have evidently decided that doubling the cost of transmission to increase their viewer-bases by only approximately 10% doesn't make sound business sense.
Unless you can receive from a full-service transmitter, then you aren't ever going to be able to view the Commercial channels.
Freesat is an alternative you might like to consider.
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Brian Tullett: Perhaps try manually tuning.
The presence of ITV2+1 without that of ITV2 means that COM4 is present and PSB2 isn't.
See here for list of services by multiplex:
DTG :: DTT Services by Multiplex
There is another retune which affects all transmitters across the country and this will take place on 17th October:
Freeview channel number changes to go ahead: HD, Adult move on 17 October 2012 | ukfree.tv - 10 years of independent, free digital TV advice
Yes, I agree it is totally crazy having retunes every fortnight rather than coinciding the events...
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Deeptheone: If your TV was tuned to Midhurst prior to Wednesday, then you will have lost PSB2 (ITV1 etc) and COM4 (ITV3 etc) on Wednesday as they changed UHF channels (frequencies) in the early hours. On the basis of your neighbours' experiences, they were tuned to Midhurst. However, if you didn't loose PSB2 and COM4 on Wednesday, then you can't (or couldn't then) be tuned to Midhurst for them.
At your location Heathfield is in the opposite direction as Midhurst and I wonder if your receiver has been tuning to it instead of Midhurst.
See this page to identify which services are carried on which multiplexes:
DTG :: DTT Services by Multiplex
For example, PSB2 carries ITV1, ITV2, Channel 4 and others.
For one service carried on each multiplex, view the signal strength screen to see which transmitter it is tuned to. Those of Midhurst and Heathfield are:
PSB1 | BBC One | Midhurst=C55 | Heathfield=C52
PSB2 | ITV1 | Midhurst=C56 | Heathfield=C49
PSB3 | BBC One HD | Midhurst=C58 | Heathfield=C47
COM4 | ITV3 | Midhurst=C54 | Heathfield=C42
COM5 | Pick TV | Midhurst=C59 | Heathfield=C44
COM6 | Film4 | Midhurst=C50 | Heathfield=C41
If these aren't correct, then you may have to manually tune but only having blanked out what's stored, probably by running it through an automatic tuning scan with the aerial unplugged.
For PSB3, the HD one, you might find that the TV needs to be told that it uses DVB-T2 mode when manually tuning. DVB-T2 is what is used for HD transmissions and DVB-T for standard definition ones. With some receivers, the manual tuning function doesn't automatically detect which it is.
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n hobson: The answer depends on which transmitter the aerial faces and which channels are affected.
Refer to this page and identify which groups (multiplexes) are affected:
DTG :: DTT Services by Multiplex
There are six and each uses a signal of its own: PSB1, PSB2, PSB3(HD), COM4, COM5, COM6.
Some possibilities:
- If your aerial faces the Whitby relay which is on the industrial estate off A171 Stainsacre Lane then be aware that it only carries PSB channels. The aerial will be vertical. So if the COM channels are poor, then these must be being picked up from elsewhere. As the aerial was installed for reception from the Whitby transmitter, then isn't meant for receiving from elsewhere and therefore poor or intermittent reception may ensue; basically, you're on your own!
- If the aerial points to Bilsdale, it will be horizontal. If the PSB channels are poor, then perhaps it has tuned to the Whitby relay for them instead and it is this which needs correcting. The way to avoid Whitby transmitter is to have the aerial unplugged for the last 50% of the scan.
If you say which channels it is that you are having difficulty with and which transmitter the aerial faces, then a more exact answer can be provided.
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mandy : The aerial system will have a powered amplifier for distribution of the feed from the aerial. The likely answer is that either it has failed or there is no power to it. Either way it is down to the party responsible for the aerial system to put it right or have it put right. It may be worth speaking to your landlord, although clearly there isn't likely to be anything done about it today.
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Ian: You are missing COM5 multiplex. See here for an explanation as to a possible cause for loss from Bilsdale after switchover:
Bilsdale (North Yorkshire, England) full-Freeview transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Try a manual tune first, if your receiver allows.
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Andrew Haddow: There is no requirement to tune the Humax before the TV, even though it is daisy-chained on the aerial feed it doesn't work that way.
Also, in order to manually tune, you do not need to go to the logical channel number (LCN) of one of the services on the multiplex. So you do not need to switch to LCN15 before attempting a manual tune to C24. You go to the manual tune screen and select/enter the desired UHF channel, it will scan and find the services that are being received The services' designated LCNs are broadcast over the air and so they assume their correct positions as a result of this.
The fact that you had COM5 and COM6 previously means that they were "found" when you ran the scan. It's not so much that they were lost when you retuned, but that they weren't found on the subsequent scan. This is because the retuning procedure must first delete all the channels that are stored before scanning/looking for those available.
Signals vary and particularly so in situations such as yours where you are on the fringes and using an aerial that doesn't point in the right direction. For this reason, your reception could be intermittent.
You will have to consult an aerial installer with a view to reception from either Winter Hill or Pendle Forest. You may wish to retain your current aerial on Darwen as a backup. It probably won't be suitable for reception from Winter Hill or Pendle Forest.
As you probably know, Darwen Moor at 200m above you is in the way of Winter Hill. It would appear that the high ground north of Belthorn is higher than the line of sight between you and the Pendle Forest transmitter, so it won't be a given.
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Sunday 7 October 2012 4:38PM
Andrew Haddow: The full list of the six Freeview multiplexes along with the services they each carry are listed here:
DTG :: DTT Services by Multiplex
The COM muxes are carried on the main transmitters and some larger relays which means that they do not have as extensive a coverage as the PSBs.
If your aerial points to the Darwen transmitter, then it only carries PSB channels. This means that if you ever received the COMs then you were receiving them off-beam of the aerial. As such, there is no advice to offer on reception because the aerial was being used to receive a signal that it wasn't installed for.
Whether you can reliably receive the COMs is another matter.
On the basis that Pendle Forest is vertically polarised, which is the same as your aerial (which it should be for Darwen), then I think that it is most likely to have been providing the COMs rather than Winter Hill, which is horizontally polarised.
You should be able to identify which transmitter(s) you are receiving from by viewing the signal strength screen whilst tuned to one service from each multiplex.
The three main possibilities at your location are suggested by Digital UK as Darwen as excellent and an outside chance of Pendle Forest and Winter Hill.
Channels used by these are:
PSB1 | BBC One | D=C45 | WH=C62 | PF=C28
PSB2 | ITV1 | D=C49 | WH=C59 | PF=C25
PSB3 | BBC One HD | D=C42 | WH=C54 | PF=C22
COM4 | ITV3 | WH=C58 | PF=C27
COM5 | Pick TV | WH=C61 | PF=C21
COM6 | Film4 | WH=C55 | PF=C24
I've abbreviated the transmitter names: D=Darwen; WH=Winter Hill; PF=Pendle Forest
The services you've mentioned are carried on COM5 and COM6. If you have ITV3, then bring up the signal strength screen and see if it is tuned to C27 (which is Pendle Forest) or C58 (which is Winter Hill).
Having established whether it is Winter Hill or Pendle Forest that is providing COM4 (if at all), then you may be able to manually tune COM5 and COM6 from the same transmitter.
As I say, reception of such signals is using the aerial for something that it wasn't installed for and therefore you may be prone to intermittent or no reception as a result.