All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Ken Morrison: You can receive free-to-air channels with your old Sky box. You should be able to try it now, with your dish at home.
"Freesat" is the brand name given to a free-to-air satellite service not associated with BSkyB.
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John V Osborne: Judging by the fact that there are houses with aerials pointing at either transmitter, and in some cases an aerial on each, and looking at the size of those aerials I suggest that perhaps reception from each is about the same.
You don't have line-of-sight to either because you live in a dip. This is probably the reason for higher gain aerials, as at 30 miles from Crystal Palace you aren't that far away, considering its power.
You may find that reception from Crystal Palace varies over time because your aerial is facing the wrong way.
If you are able to pick up the PSB channels from Sandy Heath well with your Group A aerial then perhaps you would be able to pick up the COMs with a suitable aerial.
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Algy: There is, since switchover, a two-tier terrestrial television transmitter network.
The coverage of the Public Service (PSB) channels (in theory) mirrors that of the former four-channel analogue network.
The Commercial (COM) channels fit in where possible and where the licensees wish to pay for transmitters. The channels/frequencies given to them are re-used in closer proximity than the PSB channels are re-used. Consequently, they are more likely to be limited in their coverage by interference. This is where the signal is present, but that there is another transmitter that is co-channel and so degrading (interfering with) the wanted signal. This is why the transmission power of the COMs is lower than the PSBs.
The Andoversford relay transmitter is co-channel with Oxford's COMs, albeit vertically polarised. Perhaps its signals are carrying further, at times, and this is what's causing your difficulty, although they are on very low power. It might be worth seeing if neighbours have the same issue.
You are, as you say, high up and appear to have quite a clear path to Oxford so the lower power COM channels may be otherwise perfectly adeqate to reach you.
The high ground at Blackheath Clump, north of Burford, is in your first Freznel zone (look it up), as the terrain plot shows:
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
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michael: Emley's COMs ("the others" you refer to) are co-channel with those of Moel-y-Parc, which comes in quite well across the North West of England.
The coverage map on this site assumes that the signal is radiated equally in all directions as the powers that be won't realise the radiation patterns that would tell us whether this is the case or not.
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Robin Mutch: Like I say Robin, I'd be investigating the possibility of signal overload, the PSBs being at 100kW whereas the COMs being 50kW which might explain why the higher power ones are going.
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Robin Mutch: By "overload" I'm not referring to too many TVs bening connected to the aerial.
It is the level of the signal being fed into the TV which could be above that which it can handle. This is rather like turning the volume on a hifi up to maximum which usually results in distortion from the speakers because they can't handle the signal fed to them.
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john Broadhurst: I take it you are missing ITV3 as well, which means you aren't receiving any of the Commercial (COM) channels.
Where does your aerial point? If it's the West Runton relay (aerial vertical on bearing of 250 degress) then this only carries Public Service (PSB) channels.
The only way you will receive the COM channels is "if" you can pick them up directly from Tacolneston or possibly Belmont, but the latter is East Yorkshire/Lincs region rather than Anglia.
Tacolneston is on a bearing of 189 degrees with aerials horizontal. Looking at Streetview there are one or two aerials on this transmitter.
Some of the houses on the north side of the road look to have rooflines that are in the shadow of those on the other side, so this could perhaps increase the difficulty.
The general difficulty with reception from Tacolneston along the north Norfolk coast is that the ground goes downwards to the sea. For that reason Belmont (between Market Rasen and Louth) is generally the best main transmitter, although at your location it isn't so good as you are quite a way east and would be relying over reception over water.
A new taller mast was built at Tacolneston for switchover, so the chances may be greater than before.
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Danny: Maybe Freesat is the most straightforward and likely to work solution to increase viewer choice (including ITV4).
The only way to get it via terrestrial (Freeview) is if reception from a full service transmitter is possible. In your case you "might" be able to receive from Lancaster. This would give you BBC North West and ITV Granada, although you may be able to combine it (using a diplexer) with you existing aerial to give you the Commercial channels with BBC NE&C and ITV Border.
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Friday 21 June 2013 12:33PM
yaz: If I am right in understanding that the aerial lead coming into your room has an unpowered splitter on the end, with one output connecting to the TV and the other to the box, then connect the aerial lead directly to the input of the box and connect the output of the box to the input of the TV. That is, daisy-chain the box.