All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Francis Byrne:
The Bit Errors for C46 may suggest interference of some sort. You haven't got anything with an RF output running have you, old VCR, games consoles etc. If so change the channels to something above 60 if possible.
Yes, it's a big disappointment that UHF Channel usage for each of the channels haven't been updated for all the post 700MHz changes.
C46 is used by a lot of quite/very low power relay transmitters but none very near you, and in most cases they also use C40 & C43. This is also true of the high power transmitters that use the same channels so why C46 should be affected is rather strange.
Just for reference some of the NI relays are Newcastle (800W), Kilkeel (400W), Cushendall (5W), Carnmoney Hill (16W), Camlough (500W), Plumbridge (5W), Edemy (11.2W), Lisbellaw (4W), Castlederg (2.2W).
Some of the high power (>10kW) ones are Preseli, Llanddonna, Bilsdale, Rosemarkie, Keelylang Hill, Black Hill, Heathfield, Hannington, Bluebell Hill, Sutton Coldfield, Tacolneston,
All are far enough away not to be an issue in normal circumstances.
Are the figures still the same now or have they changed? There has been some Tropospheric Ducting around which might have resulted in interference.
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Alan_C:
Almost forgot, do you have anything connected with HDMI? Keep the leads well away from aerial and flyleads, as they can cause interference especially to C55.
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Alan_C:
Hi Alan. I'm afraid most of the DAB/FM pages that I've been on in recent times (IIRC) are like that. I don't know if it's a bug in the software or if it's been disabled because of issues with the coverage maps, and transmitter locations on the map aren't always correct. Whichever, the site owner doesn't seem to have the time to fix it all!
The best places to check DAB coverage are putting in your postcode at
ukdigitalradio: Home or DAB Digital Radio - Pure, Roberts, Stations, DAB, Evoke, In Car, Online, Portable, Digital Radios, Highway, One, Station, Sony or for BBC DAB reception issues Issues with DAB | Help receiving TV and radio
(The BBC also have Problems with analogue radio | Help receiving TV and radio for FM/MW/LW)
There are some interesting pages at Digital Radio (DAB)
For loads of more technical info see DAB Ensembles WorldWide | UK National & Regional (even worldwide on the site).
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Alan_C:
It's probably fair to say that none of the coverage maps or predictors are 100% accurate, the less variable the local terrain, the more likely they are to give some believable figures, that said the Freeview Detailed Coverage Checker doesn't show any variation across the 6 main muxes, only COM7 very marginally less reliable for your postcode.
It does also show very good reception from Stockland Hill (bearing 223 degrees) and as it happens some good and variable reception from Wenvoe (bearing 320degrees)! Stcckland Hill is 38km from you, Mendip 22km, Wenvoe 59km.
The aerial is likely to have some moderate side lobes to the rear sides, I'd try just out of curiosity to see what you could pick up without moving the aerial (with the amp connected). Stockland Hill's UHF channels are C26+, C23+, C29+, C25-, C22-, C28- for PSBs1-3, COMs4-6, no COM7 or Local. Don't worry about the +/- offsets, TVs tune quite happily.
Now, well done for trying the long cable, all that you did were useful checks. One query in relation to the amp, when you had the aerial connected directly (first set of figures), was the amp still switched on/powered up? IF so, try the aerial connected direct again with the amp powered off and see if there's any differences (this should make sure that the amp isn't causing any interference).
The set of figures with the amp in circuit are now suggesting too much signal, hence the drop in the quality figures, that's why you found some improvement when you introduced that splitter giving some attenuation as mentioned in your original post. Although this C48 problem is still another issue (eg. it could be aerial position in relation to maybe your solar PVs or other things, if it wasn't a problem with the amp itself which the check I've just mentioned should confirm).
Its also worth considering other possible sources of interference that may be affecting C48 if the amp is eliminated. Try switching off anything that might be running constantly when you've been looking at figures or having problems with reception (not fridges/freezers/central heating as these go on and off) but any lighting running off transformers, fluorescent fittings, compact fluorescents, LEDs, or any other discharge lighting eg.outside. Anything else that has any electronic control that's powered all the time.
As you have a 4-way amp/splitter, I assume you may have at least one other TV elsewhere in the house. Does it show similar relative figures for each UHF channel?
If there doesn't appear to be any problems with the amp, then it would probably a good idea to get one of these eBay item: 310039226920, Coax TV Aerial Attenuator Adjustable Variable Between 0-20 dB Reduces signal | eBay
IF the amp does turn out to be an issue then any replacement might usefully have a variable gain control.
If we've got to the point that everything else that could be causing interference or poor reception has been eliminated, then we are most likely down to aerial position. Whilst absence of a meter might making things somewhat tricky with a bit of trial and error, initially we're only interested in whether reception is being adversely affected by position. Without the amp in circuit, I would initially take it off the pole and remove the pole and just move the aerial sideways and say back away from the solar PVs and just have it sitting on the beams/loft floor doesn't matter if it say overhangs your loft access or whatever, to start with we're just looking for what significant (if any) changes there are in signals.
If you've got a 2nd set and it was showing similar relative figures to your main set, maybe you could position it somewhere nearer the loft which would make any to-ing and fro-ing a bit easier.
If you can post back with the info about whether the amp was on when you did the first figures and any differences if so, and any comparison with a second set, checks on other potential sources of interference etc. I can see if any of that modifies my thoughts.
I replied to your DAB post, yes I was up, had been watching news on the US election then decided to watch a film (sad I know!). COM7 is not likely to close in 2020, it's anticipated that the earliest would be later in 2021 IF any MNOs buy the SDL frequencies when the auction is held scheduled in the new year, they could then give 3 months notice to be able to use the frequencies, but equipment would need to be installed as well as suitable handsets available and this won't happen overnight. That said, Arqiva closed COM8 for commercial reasons primarily due to loss of advertising revenue in the covid-19 situation and broadcasters being uncertain about the future wanting to cut costs, so that might have a future effect on COM7, personally I don't think it's a high probability.
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Benno:
Due to a strange quirk, it may have ended up in the 800s with a few other channels. I've come across a few others with similar problems. Try retuning as follows -
Unplug the aerial and do an automatic retune. This should clear all previous tuning as no channels should be found. (If perchance you find it hasn't cleared all previous tuning you may have to do a factory reset).
Plug the aerial back in and if you can do a manual tune, do so for the correct UHF channels for Pontop Pike.
In the multiplex order PSBs1-3, COMs4-7, Local - they are C39, C42, C45, C32, C34, C35, C55, C33
Whether you actually get COM7 or the Local Multiplex will depend on your precise location.
If your set doesn't have manual tune, just do an automatic one.
Hopefully all channels will be restored correctly.
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Ian Tompkins:
I'm not familiar with the 5000T but I seem to recall one of Humax's helpful suggestions for any problem is to do a factory reset! Hmm.
A few questions which may help with further responses -
Do you have the latest firmware? - UKTFAE 1.03.51
Does this problem occur with all HD channels or just certain ones, if so which ones?
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Ken Marchant:
Sony Movies Christmas (a seasonal rename of Sony Movies Classic) is transmitted on Local Multiplexes. Sony chose to move a number of their channels to Local multiplexes over a year ago. (See Channel listings for Industry Professionals | Freeview for which channels are on which multiplex).
Local multiplexes are only transmitted from a limited number of transmitters serving large urban centres of population and the signals are generally beamed to those areas at a lower power, but the transmission mode helps improve coverage (but it reduces bandwidth - space for the number of channels).
Transmitter powers (of all multiplexes) are set to try and give the best coverage of the areas they serve under normal conditions, without causing interference to other transmitters that have to use the frequencies.
Sutton Coldfield has 2 frequencies for the Local multiplex (most only have one!), C48 at 10kW which is beamed SW (towards Birmingham) and C36 at 1kW beamed N to cover Lichfield and surrounding districts.
Unfortunately you are slightly too far to the west as well as some distance away and if you are on the Stafford side of your locale, reception may not be as good. The Freeview Detailed Coverage Checker predicts some very variable reception of the Local multiplex for you as a consequence, whilst still giving very good reception of the main multiplexes. You may find reception of the Local multiplex varies maybe throughout the day or is quite weather dependent.
Whilst you have 6% Signal strength, it's the Quality figure that's a lot more important, if that is 0%, then you are probably wasting time and money trying to do anything about it (too much interference on the channel - but do check you haven't got any equipment with RF outputs such as older VCRs, game Consoles etc. that are set anywhere near C36. If you have, try resetting to C60 or above).
If you don't have 0% Quality, whilst you could try boosting the signal with an amplifier, as you have 100% signal on the other multiplexes, you are in danger of having too much signal for the other multiplexes which could cause front end overload and reduced sensitivity, as well as pixellation and/or sound breakup.
If you choose to try that option you should use one that has variable gain or use a variable attenuator between the amplifier and TV set to help ensure that you can reduce the signal to prevent overload - which of course might mean you still don't have a satisfactory signal for the local multiplex!
I'd suggest that you monitor your signal on C36 and if the Quality figure is reasonable (as well as maybe a slightly better Signal strength) for a reasonable amount of time, it may be worth a go, but I'm doubtful.
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Mr peachey:
StevensOnln1:
Quite a few people are encountering these nag screens which seem to be popping up on the channels on the ArqA & ArqB multiplexes (but not SDN) between LCNs 25-55.
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Charlie Folorunsho:
If you are in the UK, have a device with Freeview Play and an adequate broadband connection, you can select a number of programmes from various channels upto 7 days ago.
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Sunday 8 November 2020 4:06AM
Alan_C:
I assume those figures are without the amp. Can you put the amp in and see how the figures compare without changing anything else.
That quality and signal strength on C48 is of concern. The SDN/COM4 mux is the only one that hasn't moved UHF channel at sometime or other!
That XB10K is a good aerial and on paper the gain at C55, C48 & C35 should be pretty much identical.
The Freeview predictor say all the main muxes should be blowing your windows out, but being in a loft will attenuate things. Without an amp, and lower transmission power for C55, that may make a significant difference. The Local mux on C30 is the exception for which you may get nothing as it's beamed N towards Bristol.
Your aerial should be pointing at a bearing of 22 degrees (NNE) but may need tweaking because of its location in the loft.
To address this C48 performance. Lots of things to check.
Have you got anything with an RF modulator running which might be causing interference eg. RF output from a VCR or other devices, Games consoles and the like. If so change the channel to 60 or above if possible.
Check you have no breaks or kinks in your downlead or any flyleads you may be using. Pre-made flyleads are often a problem with breaks at the back of the connector. Check connections on any walls plates for corrosion etc. None of this will necessarily affect all multiplexes as it can cause standing waves to be set up in the cable and what frequencies are affected will depend on cable lengths etc.
Assuming you've not found issues with downlead, flyleads etc, consider position of the aerial in the loft - check its not got any metal objects nearby - flues etc. electric cabling, especially in the direction it's pointing. Similarly partition walls. Also roof flashing, solar panels and the like.
If nothing else has come to light, try altering the bearing slightly and see how it affects the figures.
If that doesn't make much difference try altering it position, move it backwards, forwards, sideways etc.
Post back the figures with the amp in circuit first, that may be quite revealing.