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All posts by Chris.SE

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

Mendlesham (Suffolk, England) DAB transmitter
Saturday 19 November 2022 8:42PM

Richard Cooper:

Well, believe it or not, depending on the checker you use, Mendlesham is listed as one of the possible transmitter for both the BBC National multiplex on 12B and the Local multiplex on 10B carrying BBC Radio Norfolk. However, I would agree with you that other nearer transmitters carrying either 12B or 10B or both are more likely.
Not that it makes much difference to the problem reported, interference is the most likely cause.

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Rowridge (Isle Of Wight, England) transmitter
Wednesday 23 November 2022 2:43PM

Martin Stevens:

By Basingstoke, I assume he's just using that as the general direction for the Hannington transmitter, which in your postcode will be due N of you, where as Rowridge is compass bearing 197 degrees - almost SSW.

Whilst reception can vary across a postcode, the predictions generally are not as good for Hannington for the PSB multiplexes and can be much poorer for some of the much lower house numbers in your postcode. predictions for the COM multiplexes are about the same for each transmitter, but they are not as good as they use half the power that the PSB multiplexes do. Strangely the postcode is predicted to get good reception of the Local multiplex from Rowridge which is lower power again but a different transmission mode so tends to get further than you might expect. All this is based on using a Horizontally polarised aerial (rods or aquashed Xs horizontal).

Rowridge (one of very few) also uses Vertical polarisation for the 6 main multiplexes but NOT the Local multiplex and reception is predicted to be better for the COM multiplexes and about the same for the PSBs.
See Channel listings for Industry Professionals | Freeview for which TV channels are carried on which multiplex. If you aren't interested in the channels on the Local multiplex, then a vertically polarised aerial could be best.

That all said, reception will be affected by very local conditions and there may be new obstructions on the line of sight since the general predictions - eg. very tall trees or buildings in the general SSW direction. If there aren't then maybe your installer isn't quite as clued up as he should be, is he CAI approved? I'd certainly be looking for a second opinion. Which way are you neighbours' aerials pointing? And what polarisation do they use?

If you need signal for more than one TV/box/outlet and need an amp/splitter, then make sure any amp is one with a variable gain control as too much signal can be as bad as not enough.

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James Watkins:

I'm afraid as you haven't given a full postcode, we can't say if there are any specific conditions that might affect reception in your locale.
The transmitter has had no reported faults in the last 5 days and it hasn't been listed for Planned Engineering in recent weeks.

Have you checked that your aerial is still pointing in the correct direction (compare to neighbours if need be) as a result of recent high winds and that the downlead is securely fixed and isn't flapping in the wind? How old is the installation?

Check all the connections behind your TV and anywhere else that's accessible.
Have you changed anything recently? Make sure you don't have HDMI leads close to your aerial leads or flyleads as these have been known to generate interference.
If you have an amp/distribution splitter make sure it still has power. Check it's still working - connect the aerial direct to one outlet and see if signal returns.

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Well done for finding the problem.:)

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Barry Britton:

Hmm, that's certainly an odd one as you say multiple TVs affected, if it had been one set I would have suggested checking the tuning.
It's possible the transmitter was still of air, have your signals returned yet?
if you still had no signal, do/did your neighbours have the same problem?

BT25 is a large area and whilst the main transmitter at Divis might be your most likely one there are some relays that you might use in some parts. Without a Full postcode, it's not possible to be more specific. The Dronmore relay is listed for Planned Engineering and if you are using that, it could be the reason for no signal.

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Michael Arnold:

It's most likely to be some sort of electrical interference, but to try and narrow it down, more information would be needed.

How frequently is it occurring? Once a day, several times a day, once every few days, etc.?
What times? Does it always occur at the same time(s) of day/night?
Does it coincide with the use of any particular equipment - electrical or electronic? - eg. central heating coming on, recording equipment switched on, and so on?
Fluorescent or other discharge lighting being on? Even some LED bulbs can cause interference!
A motor vehicle/bike running (not diesel)?

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Philip Chadwin:

If you were recently told by the aerial fitter that Oxford is down on power, then I'm afraid he is not correct. There was Planned Engineering in the middle of August for a week and again for 3 weeks in the last part of September when there could have been "Pixelation or flickering on some or all channels".
It's not been listed for Planned Engineering since then and there are currently no faults listed for Oxford, the latter being checked with the Radio and Television Interference Service and the BBC Reception Checker.

You are 47km from the transmitter, have line of sight, and according to the BBC and Freeview's reception checker you should get good reception of the 6 main multiplexes and reception of the Local Multiplex (possibly variable) on UHF C22.
What make and model aerial have you got? In your location, it should be pointing at compass bearing 53 degrees - that's 8 degrees east of NE, and its rods (or squashed Xs) should be horizontal.

Now assuming there are no faults on your aerial installation and the coax is a high quality double screened type such as CT100, then there could be two possibilities here.

If that booster was fitted and set up when there was Planned Engineering, it's now possible that you have too much signal. One of the symptoms of that can be appearing to have a strong signal, but having 0% Quality! If the booster has a variable gain control - turn it down. You do NOT need 100% signal (which could be much lower) but you should have 100% Quality. Is this a splitter/booster with several outputs?

If there is not a variable gain control, try unplugging the aerial from the input and connect it straight to the feed for your TV and then check (& report) the Signal Strengths and Quality for each of Oxford UHF channels (see my post just before yours).

One other possibility is new interference from a mobile phone mast that was "upgraded" or installed in August. There were 3 which are about 0.5/0.6km from you in roughly a NNW direction and another 1.2km away in roughly a NNNE direction. These ought not to be giving you a problem but with excess amplifier gain they might, and of course a new mast could have been installed as well.
According to your postcode won't have received a postcard warning of such problems BUT I've heard of several cases where cards have not been sent.

If turning the booster gain down doesn't solve the problem, or your checks without the booster don't produce 100% quality on all multiplexes, then it would be worth contacting to obtain a free filter.

Put into your web browser address bar. Play around with their website if you wish, but it can tend the take you round in circles!

From the home page, click on FAQs at the bottom centre of the page, then on the FAQ page click "About Restore TV" towards the bottom right and select "Do I have to pay to call Restore TV?" which will open a window showing their freephone number 0808-1313-800.

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Nick Lloyd:

There don't appear to have been any reported faults for the transmitter in the last 5 days, and it's not been listed for Planned Engineering recently.

You're probably around 3km from the transmitter and should be getting a very good signal. The aerial should be pointing at around compass bearing 351 degrees - that's 9 degrees W of due N, and it's rods (or squashed Xs) should be vertical. Check that your aerial looks intact and is still pointing in the correct direction, also check the downlead is secure and not flapping in the wind.
How old is your aerial installation?

Check all the connections behind your TV etc. Have you changed/moved anything recently?
Retuning when you've got pixellated pictures or no signal, when you've been correctly tuned, is never a good idea. Most times it'll just clear your correct tuning, and you end up having to retune again when your signals improve and you might not know when that is and have to try several times.

Have you had a postcard from at all? Any new mobile phone masts nearby?

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Wenvoe (Cardiff, Wales) Full Freeview transmitter
Tuesday 29 November 2022 12:12AM

A reminder that COM7 has now closed (COM8 closed in 2020) so,
The UHF channels for Wenvoe are C41, C44, C47, C42, C45, C39, C37 that's in the multiplex order BBCA/PSB1, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6, Local.
(C means UHF channel).

Whether or not you can receive the Local multiplex will depend on whether you are generally North of the transmitter and specifically your postcode to determine if you are likely to get adequate signal.
Also , see Channel listings for Industry Professionals | Freeview for which TV channel;s are carried by which multiplex.

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Simon Deacon:

As you haven't given a full postcode, it's impossible to say if there are particular issues affecting reception in your specific area, however I can find no faults listed for the Wenvoe transmitter and it's not currently listed for Planned Engineering. As far as i can deduce, the transmitter is functioning normally.
How far away from you is this 5G mast?

Some more information is needed to start making sensible suggestion about the most likely cause of your problems, otherwise it's a simple case of test/check everything and by process of elimination find the problem.

What sort of aerial have you got, how old is it? Have you checked that it's still pointing in the correct direction and its rods (or squashed Xs) are horizontal (for Wenvoe). Is the downlead secure and not flapping in the wind?

Do you have an aerial pre-amp located on the mast or do you have a booster amp/splitter for feeding more that one TV/device?
If you have more than one TV, are you seeing the same problems on them all?
Is your TV a "Smart" TV, if so, how is it connected to the Internet - by Ethernet cable or Wireless?
Have you looked in the TV Tuning section to see what the Signal Strength and Quality (or Error/BER) figures are for each UHF channel at the Wenvoe transmitter.
(See the Wenvoe transmitter page for more information).

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