All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
David George:
The BBC are normally very good at listing any faults for multiplexes carrying their stations, but I can't find any faults listed for Mendip or Exeter (to the north of you, no doubt within the beamwidth of your aerial pointing at Mendip). Exeter also transmits all the main National multiplexes as does Mendip. It might get signals from Mendip, I'm not sure, but the Mendip TV transmitter is currently listed for Planned Engineering so there's a possibility that DAB signals might have been interrupted.
I don't know how directional your aerial is (possibly not highly) as BBC Somerset is transmitted on Block 10B: 211.648 MHz from the Taunton transmitter as well as Mendip.
I would have expected you to also get Block 11C: 220.352 MHz from the Exeter transmitter carrying BBC Radio Devon as well as some commercial stations.
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Andy Banks:
Well I can't find any reports of faults affecting PSB2 at Heathfield, which doesn't come as much of a surprise, as normally it's only multiplexes with BBC channels where reports are reliable. The transmitter isn't currently listed for Planned Engineering either, although it was last week! Maybe the work wasn't completed. It won't be the first time that the lists haven't been 100% accurate!
Are the problems still continuing?
Are any other channels not on PSB2 affected?
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steve phillips:
Now it depends on exactly where you are north of York (you haven't provided a full postcode) but a number of locales in that general area can receive signals from Bilsdale, and reception predictions from the new temporary Bilsdale Tower are good.
Bilsdale does indeed use C27 for PSB1! Multiplexes PSB1 & 3 swapped UHF channels back in February 2020 IIRC, the listings at the top of the transmitter page didn't get updated (the site owner hasn't found time to do all the updates after the 700MHz Clearance programme!).
But from one of my posts on the Bilsdale pages -
Bilsdale's UHF channels are C27, C24, C21, C43, C46, C40, C55 that's in the multiplex order
BBC A/PSB1, D3&4/PSB2, BBC B HD/PSB3, SDN/COM4, ARQ A/COM5, ARQ B/COM6, COM 7
You may be aware that aerials do have some ability to pick up signals from the rear of the aerial as well as some side lobes, so it's possible that you are easily getting signals froim Bilsdale Tower at this time.
Now just to complicate matters, I can't find any faults listed by the BBC for their multiplexes at Emley, and the transmitter isn't listed for Planned Engineering BUT there is some upcoming predicted Temperture Inversion/Tropospheric Ducting which will enable signals from more distant transmitters to be more easil;y received - and that will in a few instances result in interference to normal reception (you'll see the sort of thing you have with Signal Strength varying considerably and Quality dropping, often to zero)..
The predictions I've looked at (and just checked again) hadn't shown this affecting your area until tomorrow, and its likely to get quite severe over the early part of the weekend - but predictions are predictions!
My best suggestion would be to manual tune, if you can't get a stable enough signal from Emley then try Bilsdale's channels but I'm afreaid it's a case of things will likely be disrupted and not remain stable for a while.
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Just a reminder, as my last post with the information was a while back, that -
Bilsdale's UHF channels are C27, C24, C21, C43, C46, C40, C55 that's in the multiplex order
BBC A/PSB1, D3&4/PSB2, BBC B HD/PSB3, SDN/COM4, ARQ A/COM5, ARQ B/COM6, COM 7
The Local multiplex L-MDB is on C30 and generally beamed northwards towards Middlesbrough.
(These are the same channels that have always been used at Bilsdale since 2020 and currently used by the new temporary Bilsdale Tower transmitter).
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Andy Banks:
To add to my previous, there is some upcoming predicted Temperture Inversion/Tropospheric Ducting which will enable signals from more distant transmitters to be more easil;y received - and that will in a few instances result in interference to normal reception.
It is looking as though it's possible that this is already affecting some areas earlier than the original predictions, and could get quite severe over the early part of the weekend.
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Andrew Ayre:
Trying to get information about any transmitter faults or maintenance affecting commercial multiplexes (unless they carry a BBC station) is like trying to get blood out of a stone I'm afraid.
It's strange though that you say this has been going on for a couple of months, so I think it unlikely, and there's no indication on OFCOM's website that anything affecting the SDL multiplex has changed.
Have you moved your radio to a different position? Anything very local different - eg. a new building, scaffolding etc on the "line-of-sight" to Winter Hill?
The only thing I can come up with is, that since December 1st, a Local "Morecambe Bay" multiplex started on Block 11B: 218.640 MHz, the nearest transmitter called Morecambe Bay which also has the other National multiplexes apart from SDL is near Barrow in Furness. It's also transmitted from Kendal, Lancaster, & Windermere.
So I'm wondering if for some reason your radio is not coping as this new multiplex is on the adjacent block to the SDL multiplex Block 11A: 216.928 MHz, especially as the SDL mux I'm guessing will be much weaker coming from Winter Hill.
You could try clearing the radio memory and manual tuning only the SDL multiplex and see if it's moire stable. Then add each of the other muxes and see how it's affected.
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Terry Thomas:
There are no currently listed faults at Emley Moor. The reception problem you have is most likely related to the current weather conditions as mentioned in my previous reply to steve phillips -
".....there is some upcoming predicted Temperture Inversion/Tropospheric Ducting which will enable signals from more distant transmitters to be more easil;y received - and that will in a few instances result in interference to normal reception (you'll see the sort of thing you have with Signal Strength varying considerably and Quality dropping, often to zero)......"
FYI, such transmitters can be in the UK or Europe.
Both Freeview and the BBC have now issued warnings on their Update & Alerts/Works and Warning pages about possible disruption to reception.
Read my next reply to steve phillips.
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steve phillips:
The reason you may be confused is because this type of interference can be frequency dependent and/or depending on where the interfering signals are coming from, the identical channels to your normal ones may be different, so even if a broader spectrum of frequencies is affected, not all you reception will be disrupted. Sometimes they all could be.
The interference can last for seconds, minutes, hours even longer and can come and go seemingly at random.
The general advise is to NOT retune, as this invariably may cause you to lose your correct tuning and/or become incorrectly tuned to another transmitter whose signals can disappear when conditions change.
If you have become incorrectly tuned (check the UHF channels in your TV Tuning section) then it's best to try manually retuning each of your normal transmitter's UHF channels. You may have to try several times if interference is present.
Emley's Multiplexes & UHF channels are as follows, in the order -
PSBs1/BBCA, PSB2/D3&4, PSB3/BBCB HD, COM4/SDN, COM5/ArqA, COM6/ArqB, COM7 HD, & Local
C47, C44, C41, C33, C36, C48, C55, & C39/C42 Whether you get satisfactory reception of COM7 & Local muxes will depend on your aerial installation (and location).
steve, whilst you are predicted to get good reception from Emley, you are actually closer to Bilsdale and predicted to get very good reception, so it's unsurprising you can get its signals from an aerial sidelobe.
Emley is bearing 220 degrees (almost SW) from you, whereas Bilsdale Tower is 345 degrees - a few degrees N of NNW. You may get poor reception of the Local mux from Emley L-LDS (Leeds) on C39 or possibly variable reception from a Relay at Bilbrough on C42 L-YRK (York) as it's closer, bearing 214 degrees well within the beamwidth of your aerial.
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p griifin:
It's current weather conditions - there is some Temperture Inversion/Tropospheric Ducting which will enable signals from more distant transmitters to be more easil;y received - and that will in a few instances result in interference to normal reception (you'll see the sort of thing you have with Signal Strength varying considerably and Quality dropping, often to zero)......"
FYI, such transmitters can be in the UK or Europe.
Both Freeview and the BBC have got warnings on their Update & Alerts/Works and Warning pages about possible disruption to reception.
This type of interference can be frequency dependent and/or depending on where the interfering signals are coming from, the identical channels to your normal ones may be different, so even if a broader spectrum of frequencies is affected, not all you reception will be disrupted. Sometimes they all could be.
The interference can last for seconds, minutes, hours even longer and can come and go seemingly at random.
The general advise is to NOT retune, as this invariably may cause you to lose your correct tuning and/or become incorrectly tuned to another transmitter whose signals can disappear when conditions change.
If you have become incorrectly tuned (check the UHF channels in your TV Tuning section) then it's best to try manually retuning each of your normal transmitter's UHF channels. You may have to try several times if interference is present.
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Wednesday 16 March 2022 2:48PM
Zena:
The Mendip transmitter is listed for Planned Engineering this week with "Possible Pixelation or flickering on some or all channels", so this is most likely what you've been experiencing.
You didn't say which news channel, but the other news channels aren't carried on the same multiplexes (groups of channels) so may not be affected at the same time.