All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Phil B: So a log will be OK "if" it will work at your location (hope that makes sense!).
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justin ball: The COM channels may be pixelated because the Van Terrace transmitter broadcasts on them. It is two miles away and on a bearing only 9° anti-clockwise of Wenvoe. Oh, and it is horizontally polarised as well. Unless you can move your aerial to somewhere where it will be able to "see" Wenvoe, but where it will be blocked from the interfering Van Terrace, then you're not going to be able to pick up the COMs from Wenvoe.
Even if the hill wasn't in the way, Mynydd Machen is a PSB-only transmitter, so you would be no better off. This means that it doesn't carry Film4 or Sky Sports, to name but a few.
The predictor suggests that you have a good chance of receiving from Mendip. Have you tried manually tuning to C58 for its HD (switching to DVB-T2 mode if there is an option)? Do you have two aerials or are you tuning to one of the transmitters with the aerial not facing the right way?
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Ian Taylor: Bilsdale, as is common with all main stations, is expected to be switched by 6am:
Digital UK - Relay transmitter switching times
I believe that the analogue is usually switched off some time after midnight and before 1am. When the digital comes on air is dependent on how long it takes the engineers to make the necessary changes. Other transmitters have been an hour or two, so the 6am deadline is probably just to allow plenty of time should things not go according to plan.
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Jon May: HD will be broadcast from Bilsdale for the first time in the early hours of 26th September.
A so-called "HD Ready" TV is one that will show HD pictures but which does not have the means to receive them over the air. So it will require a separate tuner (box) to receive the four HD service broadcast via digital terrestrial television ("Freeview").
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Nedbod: I should imagine that it will be on the concrete tower else the tower is going to block reception in one direction.
See:
mb21 - The Transmission Gallery
Also, Ofcom technical parameters:
Ofcom | Tech Parameters
These show that that Silk FM's aerial height is 58m and Signal One's is 55m.
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Mark Harriman: Can you not receive Anglia programming from one of the Norfolk transmitters, such as King's Lynn?
Prior to switchover it relayed BBC One and ITV1 from Tacolneston, so two aerials (and a diplexer to combine them) were needed so as to receive BBC Two and Channel 4 from Belmont.
The diplexer combines the feeds from the aerials and ensures that only one aerial is allowed to provide each frequency channel. Thus, there is a particular channel where it "splits" and one aerial is allowed to feed channels below that and the other above it. Prior to switchover, Belmont's channels were low down and King's Lynn's were in the middle of the band and this meant that one diplexer was needed because its inputs "split" somewhere between the two.
Following switchover, King's Lynn carries all Public Service channels (BBC One, BBC Two etc, ITV1, ITV2, Channel 4, Channel 5, the four HDs and a few others). This is only the same as many other small relays do. Those who can't receive from a full-service transmitter cannot receive the COMs (this being around a 9% of the population who can receive terrestrial television).
Unforunately after switchover, whilst one of Belmont's COM channels (those that King's Lynn doesn't broadcast) is below the frequency that KL uses (as was the case before switchover), the other two are above that of KL, so two diplexers will be needed and either two aerials on Belmont or a splitter for the Belmont aerial. Obviously a KL aerial will also be needed.
Obviously, this may be starting to get costly, although I am throwing it to you as a suggestion for perhaps the "only" way for you to receive Anglia regional programming *and* the COM channels. It assumes that reception from King's Lynn or Burnham is possible at your location.
Or you could have two aerials and not combine them, but instead feed them into different receivers. This would mean that two diplexers wouldn't be needed and that a second aerial on Belmont wouldn't be needed (or a splitter for your single Belmont aerial).
So, if you only ever watch the local news and other local programming as its broadcast, then you might just have a set-top box (without recording function) for this and use it only at times that BBC One or ITV1 is broadcasting different regional content. At all other times use Belmont for these and all other channels.
For lots of information and products, see ATV Sheffield's site: A.T.V (Aerials And Television) TV Aerial, DAB Aerial, FM Aerial.
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justin ball: I was going to suggest that you may be able to have two aerials and combine the two feeds into one downlead with a diplexer. However, looking at the channels used by Mendip's COMs and Wenvoe's PSBs, this isn't going to be possible.
Mendip's COMs are on 48, 56, 52
Wenvoe's PSBs are on 41, 44, 47
You could combine these with a diplexer that "splits" at C51, but you will loose the ability to receive SDN from Mendip on C48. You will also attenuate C52 a bit because there is a slope down to the split.
Whilst you could probably do without HD from Wenvoe (on C47), and instead use Mendip's on C58, I don't believe that there is a diplexer available that splits somewhere between 44 and 48...
It is a pity that you can't receive from Mynydd Machen as, whilst it doesn't broadcast the COM channels, it does use channels in the 20s which would be ideal for combining with Mendip.
I was also going to suggest that the diplexer could be sited indoors behind your TV so as to allow you to remove it without needing to get a ladder. This would, of course, require two downleads whereas mounting it on the aerial mast you only mean the one.
The other possibility is to have two aerials with two feeds to your living room and feed them into two different receivers. Perhaps use Mendip except where there are regional variations that you wish to watch.
If you might wish to record these variations and you only have a conventional set-top box for Wenvoe, but have a PVR on Mendip, then you could perhaps feed the set-top box into the PVR via scart.
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justin ball: For lots of information and products, see ATV Sheffield's site A.T.V (Aerials And Television) TV Aerial, DAB Aerial, FM Aerial.
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David Brooks: The switchover only affected BBC standard definition services. All others increase in power in two weeks' time.
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Monday 10 September 2012 7:44PM
Phil B: Logs are wideband, but the have a much flatter response than yagis:
Gain (curves), Again