All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
rickh: If I were you, I'd wait until 18th April when Crystal Palace and Reigate have switched to digital. Then you can see how Crystal Palace fairs and whether it's worth changing the aerial for Reigate.
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Steve: Looking around your road using Google Streetview there are quite a few talls trees which could be an issue. I can't see a single aerial on Sandy Heath, but a few have an aerial on Sudbury and one on Crystal Palace.
This perhaps suggests that the trees put paid to reception from Sandy Heath. Maybe your neighbours could advise as to how good their Sudbury reception is.
If you do go for Sandy Heath, then its Public Service (PSB) channels are Group A (first third of the band) and Commercial (COM) channels are Group B (middle third of the band). Thus, if your current aerial is a Group A one (which all of Crystal Palace's channels are before and after switchover), then it will work for Sandy Heath's PSBs.
If you go for Sudbury, then its PSBs are Group B and its COMs are Group C/D (top third of the band).
Wideband aerials trade sensitivity within each Group with increase sensitivity across the whole band, particularly being less so on Group A channels. See here:
Gain (curves), Again
In summary:
- Crystal Palace would appear to be your best bet from a signal strength point of view on all channels. However, it gives you London programming.
- Sandy Heath may be blocked by trees; you can perhaps see much better whether this is the case than Streetview shows.
- From what I can see, no one has an aerial on Sandy Heath. You could perhaps take a walk around your area and see if this is the case, perhaps identifying why it may be the case (e.g. trees).
- Whilst the Digital UK Predictor suggests that reception of Sudbury's PSBs will be "poor" and its COMs "variable", there are a number of aerials on it. The predictor's calculation of poor PSBs could be as a result of another transmitter using the same channels. Aerials have greater rejection of unwanted signals in some directions than in others, so this may be less of an issue, depending on that factor.
- For full service from Sandy Heath or Sudbury, Group aerials that cover a third of the band will not be sufficient. Either a single wideband aerial (perhaps a less favourable option for Sandy Heath with its PSBs being Group A) or two Group aerials diplexed (combined) together into one downlead. Or for Sudbury, a single Group E aerial (top two thirds of band).
- If you do go for Sudbury, then its COMs are on low power until 27th June, so will probably be unavailable at your location until then.
- Sandy Heath's SDN multiplex (ITV3 etc) is on low power until 9th May, so may be unavailable until then.
For lots of information about aerials, see ATV Sheffield's site www.aerialsandtv.com
See the page on aerial Groups Aerials, TV Aerial and Digital Aerial
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Malcolm Ward: No, you cannot convert signals from a satellite into ones that a "Freeview" receiver can work with.
You will need to either:
1. Purchase satellite receivers (e.g. "Freesat") for all rooms served by the dish, or;
2. Install a terrestrial aerial.
It is likely that for each wall outlet, there is a cable (or perhaps two cables) from the dish to the outlet. You could therefore use the existing cabling for terrestrial services. To do this you would need to remove the cables from the satellite dish. Then install a terrestrial aerial which goes to a splitter (either powered or non-powered). Each output of the splitter would then connect to each cable you've removed from the dish. At each aerial point replace the threaded F-connectors with coax ones. This would save you having to re-cable.
The only thing to be wary of is that not all areas can receive all Freeview channels. If you are in an area served only by limited channels, then you may decide to go down the satellite route.
If you give your location, preferably in the form of post code (or perhaps nearby post code) then an assessment can be made as to the likelihood of reception of all Freeview channels.
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L Sperring: You're picking up the Welsh transmitter Wenvoe.
Run the tuning scan with the aerial unplugged up until 60% (then plug in).
This will hopefully miss out Wenvoe.
Having done this, you will probably be missing ITV3. Go through to manual tuning if your receiver allows and tune to UHF channel 48. If you're missing Yesterday, then do the same for UHF channel 52 and for ITV1 it is channel 54.
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Malcolm Ward: I should point out that if you are in an area served by Mendip, then you will be likely to be able to receive all Freeview channels.
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A: "ArqB" is an abbreviation for "Arqiva B" which is the name of COM6 multiplex. Arqiva is the name of the company that owns and runs all of the transmitters. It has two multiplexes, hence the A and B suffixes.
For a full list of services by multiplex, see DMOL Post-DSO Multiplex Channel Allocations
The transmission power does not vary by time. The days of God Save the Queen being played and then the transmitter being taken off of the air are gone.
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Steve: I hope that I've gone in at too high a level. If I have, let me know.
If you are considering getting in a professional rigger, then can help to have an appreciation of the potential issues.
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NewForest: It is done in two stages so as to allow those who do not have equipment that will work after switchover time to purchase without leaving them without any television.
In some cases, people may have digital receivers that will not work using the new post-switchover transmission mode. There will also be some others who do not have any digital receiver whatsoever.
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Monday 2 April 2012 10:24AM
gary: The switchover dates for Crystal Palace are 4th April (BBC standard definition goes to full power) and 18th April (the other multiplexes follow).
According to the predictor, Heathfield is your best bet (after the limited channels from Steyning) and will also give you Meridian regional programming, but that will only be available to you when it switches over on 13th June.