All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Paul Dursley:
Hi Paul. Well there's still no fault reports that have appeared for Backwell !
That said, things do not seem right. Quality on all multiplexes shoudt be 10/10 (or 100%) depending how your set reports it.
As mentioned before, do check your coax connections for corrosion and/or water. Start with where your downlead terminates, be it wall plate or coax plug. Check any flyleads interconnecting the aerial to the set or other equipment. These can go intermittent etc.
How old is you aerial (roughly)? Is it accessible (without risking your safety)?
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Anonymous :
THe DAB Local multiplex that carries Three Counties Radio is Block 10D: 215.072 MHz and you are within the predicted reception area, the nearest transmitters being at Hemel Hempstead and Epping Green (according to the BBC).
I would have thought you'd get good reception on FM 92.1 from Hemel Hempstead. You might also get High Wycombe on 98.0
You can listen on-line with various Radio Players and BBC Sounds, also Freeview 720.
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Mike Startup:
I presume you mean "Retune". The general answer to which is infrequently !
As a general rule, the only things that change these days is when some of the smaller commercial operators change/remove/add channels on one of the three COM multiplexes - SDN, ArqA & ArqB.
If you receive from a Relay transmitter (Freeview Light) which only has the PSB multiplexes, these are unlikely to change. Whitehawk Hill has all 6 multiplexes and a Local multiplex (which you may or may not get depending on postcode).
See Channel listings for Industry Professionals | Freeview for which TV channels are carried on which multiplex.
You should only need to retune when you see a pop-up message on one of these minor commercial channels telling you it's changed, or when there's been a new one added (see the aforementioned list).
Be careful about retuning if the transmitter is subject to Planned Engineering (which this one is at present - see top of page) and do NOT retune if channels you normally get say No Signal or are badly pixellated - this will often just clear your correct tuning - you cannot tune to signals that are not there or cannot be decoded.
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John:
As you haven't given a full postcode, we don't know what transmitters you might be able to receive. But like a lot of rural locations across parts of the UK, you have to rely on a relay transmitter which only broadcasts the main 3 PSB multiplexes BBCA, D3&4, BBCB HD. The commercial operators do not consider it cost effective to provide the transmitters and other equipment for the small head of population that the transmitter may cover, that's assuming that there are frequencies that could be allocated that wouldn't cause interference to other transmitters. There are over 1100 in the UK.
You could always consider Freesat.
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Paul Dursley:
I wouldn't necessarily say that C22 is the only one affected, you did previously have lower quality on C28. Interference doesn't always affect all multiplexes, and we've found cases where not all lower channels are affected. It appears to be a bit unpredictable.
Can you see the connector box on the aerial? Is the cover still in place and looking intact?
Good idea to make up another flylead with your coax, especially if it's the double screened type.
If you have any HDMI connections try and keep those cables away from aerial leads, HDMI has been know to cause interference, bit it's usually been the higher UHF channels in the past.
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MARTIN wylie:
As you can see from the post before yours, and some previous ones, the transmitter is currently having Planned Engineering. If you've had no issues previously, then it's likely that the engineering work is the cause but as you haven't given a full postcode is not possible to draw any conclusions about how your reception might be affected.
Just as a side note, you should normally expect to get 100% Quality on all multiplexes. There's the possibility that 100% signal could be a touch too much and under certain circumstances overload the front end of the receiver which could also cause quality variations, however if you've not had problems previously this risk could be lower.
There's also the possibility that you might now be getting interference from a new/upgraded mobile phone mast now operating in the 700MHz band, but again we need a full postcode to check on that.
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Steve Donaldson:
Whilst your theory about the increases in power is probably correct, the geography (the seven hills that surround Bristol) suggests that the signals from Kings Weston will not reach the coverage areas of Backwell or Ubley, close but not quite, in normal circumstances.
Whilst I haven't bothered to do a line of sight analysis, I would have expected the computer modelling used by the frequency planners to have addressed this ok.
Paul Dursley:
Another check that you might try, is look at as much of your coax downlead as you can, especially any parts that are exposed to direct 'heat of the day' sunshine. Look for cracks, brittleness or bits of sheath that may be missing.
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Steve Donaldson:
Whilst I'm not going to dispute your terrain analysis and hypothesis which is always very thorough and very likely to be the cause of the problems, there is one statement that I will disagree with -
Quote "Considering what I have found, which follows below, I'm not surprised the filter has had no effect"
It is ONLY because the filter has had NO effect that it PROVES the problem is not related to Mobile Cell Interference and therefore supports the hypothesis you've presented.
Paul Dursley:
In a previous post you mentioned C22 signal Quality varying in certain weather conditions but implied that at best is was only 7/10. Would that be correct? And what sort of figure do you get for C28 in such conditions, I've got the impression that it's 10/10 for the most part.
This could also be relevant information when making a report to the BBC.
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Roger Martin:
Has the situation changed since your post?
If not, how long has the problem existed?
Whilst the transmitter has been the subject of Planned Engineering, this could be/have been the cause of your reception problem BUT I can't give any further constructive comment on that, without a full postcode to check your predicted reception.
At the time of this post Mendip COM4 transmissions appears to be normal.and there are currently no listed fault reports.
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Monday 8 April 2024 10:48PM
Paul Dursley:
Well as the set isn't finding any stronger HD multiplex signals then that why it finds Wenvoe or should I say to be more precise, puts them in HD EPG slots.
The COM mux results from Wenvoe don't "tell us" anything special, after all your aerial is vertically polarised pointing at Backwell. Wenvoe signals which are horizontally polarised, are being received of aerial side lobes etc and will therefore be much weaker than if the aerial was horizontal and pointing at Wenvoe.