All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Natasha: Further to my previous posting, I have looked at your road on Google Streetview. I have spotted only two aerials pointing to Marlborough. Most are directed to Mendip (which is westwards), with a few pointing at Hannington (which is eastwards).
If you are in one of those houses with an aerial directed to Marlborough then it might be worth speaking to an aerial installer to see if you might be able to receive the full complement of channels from Mendip.
In poor areas such as yours it can be the case that one house can receive from a particular transmitter but another next door cannot.
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Me: In the UK, the high-power transmitters are all horizontally polarised and smaller relays are generally vertically polarised.
Polarisation is not dictated by whether the transmitter is a "main" one, but more how it fits in with other transmitters that are co-channel.
Transmitters that are of the power output of Whitehawk are generally vertically polarised.
The gain of an aerial is relative to its directivity. The more it is focused into a narrower beam, the greater its directivity and gain. Removing the reflector reduces its forward gain. And its "rear" gain isn't going to be great because there are no elements in front of the dipole, let along a reflector at the "front" of the aerial.
What is it you are trying to do. Are you looking to have available the other regional channels?
The three "main" transmitters are:
- Heathfield with BBC One South East and ITV Meridian East.
- Whitehawk with BBC One South East and ITV Meridian South.
- Rowridge with BBC One South and ITV Meridian South.
So Whitehawk has the same BBC One as Heathfield and the same ITV as Rowridge.
If you can receive from Heathfield and Whitehawk, you won't be able to diplex two aerials because the channels used by each transmitter don't allow it.
Saltdean is a relay of Whitehawk, but that can't be diplexed with a Heathfield aerial either. Newhaven is a relay of Heathfield, but that can't be diplexed with a Whitehawk aerial. The reason being that all these transmitters use C/D channels.
If you can receive from Rowridge then its channels can be diplexed with one of the C/D transmitters. Diplexing it with Heathfield or Newhaven will give you ITV Meridian South, just as with Whitehawk.
One thing it might depend on is how well you can receive the COM channels from Rowridge. If you can't get them, or they are unreliable, but Heathfield's COMs are better then you are likely to prefer Heathfield as to one of your two transmitters. In which case you may use Heathfield and Rowridge.
Be aware that channels 31 to 37 "may" (depending on if the powers that be can make up their mind for long enough that it comes to fruition) come into service from the larger main transmitters, which may include Rowridge but not Heathfield:
Ten more HD channels on two new Freeview HD multiplexes on air from 2014-18 | Freeview news | ukfree.tv - 10 years of independent, free digital TV advice
For that reason, a C38 will probably be best. That will allow you to pick up 31 to 36 (and 37 to a degree) from Rowridge.
For Rowridge you need your aerial vertical. It is Group A, so a Group A yagi is best - don't use a wideband yagi!
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Peter: If you are using a communal aerial system it may need adjusting to allow the new BBC frequency through.
If you have two aerials facing different transmitters and they are connected together then this may be an issue with new BBC frequency. For example, one on Winter Hill and one on Moel-y-Parc for Welsh programming.
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Natasha: If you are to get a Freesat recorder (a PVR, which may be branded "Freesat+") you will require two feeds from the dish. If your block has a communal satellite dish, check to see what connections/sockets there are on the wall in your flat. If there are two satellite sockets then that is what you need for a PVR.
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Peter: If there is manual tuning on the receiver then you need to tune to UHF channel 50.
What about Pick TV, as that moved channel as well? It is now on C49.
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Kevin Cunningham: Perhaps there are two issues:
1. Loss of PSB2 (which carries UTV, Channel 4, Channel 5 etc)
2. No picture on RT channels.
For RT channels you may require Freeview HD receivers. Some standard definition receivers will work, but no where near all.
Saorview pictures are encoded using the MPEG4 standard whereas Freeview standard definition pictures use the older MPEG2 standard. For that reason many Freeview SD receivers don't have the capability to decode MPEG4 pictures, but Freeview HD ones definately do.
As for number 1, I put the postcode of the Post Office in Annalong into Digital UK Coverage Checker and it doesn't look great. I wonder if you might be in a poor reception area.
Try manually tuning to UHF channel 42 for PSB2 from Kilkeel.
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Andy Ell: The signal strength usually gives the UHF channel that it is tuned to, or else often gives a frequency in MHz instead.
How do you know it's Sudbury or are you just concluding that on the basis that it is BBC One East and ITV Anglia?
Yesterday is carried on one of the Commercial (COM) channels which don't have as great a reach. So you may find that you can pick PSB channels from Sudbury but not COMs. Another factor is Rouncefall which is a 4kW PSB-only relay (also horizontally polarised) and uses the same channels as Sudbury. This is fine for digital - it operates as a "Single Frequency Network" (SFN) - so you may be getting the combined effect of Sudbury and Rouncefall for PSBs, but you will only ever get Sudbury for COMs, if at all.
See here for a list of services by multiplex (PSB/COM):
DTG :: DTT Services by Multiplex
Yesterday is carried on COM6.
With Sudbury you will obviously loose access to BBC One South East and ITV Meridian.
The Margate relay is on the top of Invicta House and forms a SFN with Dover, albeit that it is vertically polarised, but again it only carries PSB channels (so no Yesterday).
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Andy Ell: COM6 (inc. Yesterday) from Sudbury is C56 and C48 from Dover.
BBC One from Dover/Margate is on C50. Ensure that it isn't tuned to Bluebell Hill on C46.
ITV Meridian from Dover/Margate is on C51. Again, ensure that it isn't tuned to Bluebell Hill on C43.
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brian lewis: Digital UK suggests that reception from Kendal transmitter may be possible at your location. This carries ITV Border, so maybe it is tuning to Kendal for that and that is the reason that the EPG doesn't populate for it.
Bring up the signal strength screen on ITV. For Winter Hill it will say that it is tuned to C59 (778MHz) and for Kendal it is C53 (730MHz).
If it is tuned to Kendal for D3&4 then the only possible explanation I can give you is that it will find it before it finds Winter Hill's D3&4.
If this is the case then either you may be able to use manual tuning or else resort to some tricky maneuver with the aerial plug so as to have it out for Kendal and in for Winter Hill.
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Monday 22 April 2013 1:27PM
Natasha: The Mendip transmitter carries all channels. You are receiving from Marlborough which is a small transmitter that relays Mendip's PSB channels and exists because reception from Mendip is difficult or not possible.
The small "filler-in" transmitters are never likely to get the full complement of channels because those that don't broadcast from such sites are run purely for profit and have no Public Service obligation, unlike BBC, ITV, Channel 4 and Channel 5. See here for an explanation:
Londonderry (Northern Ireland) digital TV transmitter | ukfree.tv - 10 years of independent, free digital TV advice
There is the free-to-air satellite service Freesat which offers more channels than are available from the Marlborough transmitter, including ITV4 and Film4.
Here is a comparison full Freeview vs Freesat:
Freeview/Freesat | ukfree.tv - 10 years of independent, free digital TV advice