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All posts by Dave Lindsay

Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.

Full technical details of Freeview
Tuesday 10 December 2013 4:55PM

Bharat: It probably won't cause a problem but I suspect it isn't giving any benefit and so is surplus to requirements.

It had crossed my mind that you could use the Commtel (2 Way "Blister") amplifier in the loft, at least temporarily until a replacement for the other is found - if it is found to be at fault. However, if the connectors aren't the usual type found on TVs then it won't be suitable.


As far as the tuning goes, you need to get the TV tuned again. Manual tuning, if it is available on your set, will allow you to input the UHF channel (frequency) and should give an indication of strength/quality, this usually before you press the button to scan.

For the Midhurst transmitter, which is that you are using, BBC is on UHF channel 55 (746MHz) and ITV/C4 is on C56 (754MHz). The other standard definition channels are 54, 59 and 50 (738MHz, 778MHz and 706MHz respectively). If it's a HD set then C58 also needs tuning (which is 770MHz). This might be a quicker route to sitting and waiting for it to run the automatic tuning everytime do something different in an effort to restore service.

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Full technical details of Freeview
Tuesday 10 December 2013 5:07PM

Bharat: If you're using the 2-Way amplifier to split the signal and send it 2 ways then maybe it serves a purpose.

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Tuesday 10 December 2013 5:35PM

David Messser: If you're using Tacolneston transmitter, which is slight anti-clockwise of north east, then there are engineering works ongoing.

If you have manual tuning then try to restore the channels using that, so as not to have to sit through the entire retune scan.

ITV3 is on UHF channel 42 and Pick is on C45. You will have to do this until they are good enough to store. Once tuned, don't retune as all you'll do is untune it!

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Tuesday 10 December 2013 6:40PM

David Messser: How it's done depends on design of the TV. Indeed, some don't allow manual tuning.

Manual tuning, if available, is likely to be somewhere near to the automatic tuning. For manual tuning it will request a UHF channel number (21 to 69) and/or a frequency in MHz. You enter or select the channel number/frequency then it will probably give you an indication as to signal strength (give it several seconds to pick it up). Then there will be a button to add services (might be labelled "OK"). The services found will assume their designated logical channel numbers automatically.

So ITV3 will go on position number 11, you don't need to tell it that.

C42 in MHz is 642MHz and C45 is 666MHz.

C42 carries ITV3, QVC, Drama, bid, Dave ja Vu, ITV2+1 and others.

C45 carries Pick, Dave, Really, E4+1 and others.


We had a report two weeks ago from someone in IP27 who had had poor reception on one of the channels which suddenly improved. He went up to the transmitter site to find work being carried out to take the old mast down.

At Tacolneston for switchover a new taller mast was built. The old mast is a little clockwise of south to the new one, which is therefore on your side of it. So it could potentially be that your issue is as a result of work being carried out, e.g. a crane in the way.

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friendlyfairy: Without knowledge of your location, preferably in the form of postcode, it isn't possible to make any suggestions. If you don't wish to give your own then one of a nearby property such as that of a shop.

Knowledge of what you've tried would be helpful as it would mean we wouldn't suggest you do it again and it may also be helpful to homing in on a solution.

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Des Collier: The radiation pattern and ensuing coverage prediction would suggest that reception of Estuary TV in Scunthorpe is unlikely.

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Tuesday 10 December 2013 6:58PM

David Messser: Of course, I should have said ITV3 will go to position 10; 11 is Pick.

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Anthony: BBC Three HD and CBBC HD are carried on PSB3 multiplex which is the one which carries HD streams of BBC One, BBC Two, ITV and Channel 4. Thus these services are available from all transmitters.

Even if you could receive from Waltham, you won't get BBC Four HD because the new multiplex, COM7, which carries it doesn't come on air from Waltham until next year.

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Chris Burmajster: Film4 standard definition has been available from the Marlow Bottom transmitter for several months now.

The HD streams of BBC Three and CBBC are now available from all transmitters, alongside HD streams of BBC One, BBC Two, ITV and Channel 4.

The new HD channels BBC Four and BBC News are only available from 30 transmitters on lower power than the other channels. This means that their coverage is less than those of the existing Commercial (COM) channels.

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Enid Jefferies: I've had a look and it appears that poor reception is caused by the fact that the ground rises in the direction of the transmitter.

It is worth enquiring with neighbours to see if they have the same issue, particularly those in the row of six houses on your road. If they are experiencing the same or similar difficulty then this points to some change in the path between the transmitter and you. As I found out, it is in no way clear!

In short, you might be better off abandoning terrestrial and going with Freesat satellite, assuming there are no restrictions on the installation of satellite dishes and you have a clear view of the position in the sky which the satellite sits.

Kingsbridge transmitter is 3.6 miles away and its transmission power is 34W. Slapton is 3 miles away and its power is 250W. The power of Slapton, in real terms, increased at digital switchover; Kingsbridge is the same.

Whilst Slapton may appear to be the better bet - because it's more powerful - the ground dropping down as it gets closer to you (in the field behind you) is greater and you are closer to it than the drop in the direction of Kingsbridge. Plus, up on the higher ground (in the direction of Slapton) you have the trees around the village hall and the church.

If your TV has manual tuning then attempt to restore the independent channels. Once you have them stored, if they disappear, don't reset it because all that will do is result in them being lost from the TV's memory.

For manual tuning ITV/C4/C5 are on UHF channel 43 (650MHz) from Kingsbridge.


The longer, more detailed analysis and reasoning which I used to come to my conclusion is here:

Ideally, you want to be able to see the transmitter from where the aerial is sited, but this isn't always possible. It certainly isn't possible where you are and to add to that you have trees in the way.

I had a look on Google Streetview at your row of houses and those from the junction which it joins onto (it doesn't appear to have a name) up to the church and the aerials all point to Kingsbridge transmitter, which is roughly due west. Beyond the church it would appear that reception from Caradon Hill is possible.

The Digital UK Coverage Checker predicts reception, but it is in no way an exact science and particularly so in situations such as yours where the terrain isn't flat and there are lots of trees around.

It "thinks" that reception from Kingsbridge transmitter is likely to be poor, whilst reception from Slapton is rated as good for ITV/C4/C5 and HD, but poor for BBC. Sometimes the predictor throws up strange results like this (BBC poor) as all channels would usually be expected to be about the same. I can't see why that one channel should be poor so I dismiss this as possibly an error in the data which the predictor is working with.

Anyway, as I say the predictor should be used as a guide and taken with a pinch of salt.

I ran a plot of the terrain and found you don't have line-of-sight to either transmitter:

- This is your location to Kingsbridge - the high ground in the direction of Bowden is in the way and shown in red:


Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location


- This is your location to Slapton - the ground rises steeply in the field behind you and the trees around the Village Hall are in the way:


Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location


There is a farm at the other end of Sherford Down Road. In its field there are some trees that almost form a triangle - well looking at the satellite image they do anyway, see: TQ7 2BQ - Google Maps

The line between you and the transmitter goes straight through these trees and they appear to at the top of, or near the top of, the high ground over which you are receiving...

(On the terrain plot you can click the link to show the area between you and the transmitter. This shows a line between the two points and the line goes straight through those trees.).

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