All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
michael:
It's not over-technical IF you explain it, best way by a link to explanations already provided by others (as Ive always done). That picture should be simple enough for everyone to understand.Just referring to high pressure makes people believe something is being hidden from them as they know there are many occasions when there's been high pressure but no problem with TV reception.
I'd suggest you look back at all the twitter comments to FreeviewAdvice around the New Year when "high pressure" was what people were told by Freeview. It lead to all sorts of conspiracy theories. At least the BBC mentioned Tropospheric Ducting at the time on their Reception Advice pages.
I believe in trying to explain the facts in as simple a way as possible, people learn things that way.
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Tony Hillman:
As StevensOnln1 didn't mention it, More 4 is on Freeview 18, I assume that was a typo you made. If not, the listing you looked at was wrong. See Channel listings | Freeview
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Jeanne Kelly :
According to the Freeview Detailed Coverage Checker you should have absolutely no trouble receiving any of the multiplexes (groups of channels) from Winter Hill, you are only 5km from it! You should even be able to get all the Local multiplexes except possibly the one for Preston. ITV and Channel 4 are on the D3&4 multiplex (see Channel listings | Freeview ).
If this picture freezing and sound loss is a regular event at exactly those times, it sounds like some sort of major interference problem. That sort of time typically would indicate maybe a boiler starting for heating hot water or central heating unless you or a near neighbour is using some other electrical equipment regularly at that time.
This could be either due to a fault on said boiler or other equipment, or a fault on your aerial installation and/or cabling. Or maybe you've changed something in your installation recently - if so, please provide some more details and we see if we can explain any possible causes.
Other than that, you would be wise to check that your aerial seems intact and pointing in the correct direction and that your downlead looks undamaged (especially if it is old). At your location the aerial should be pointing at a bearing of 265 degrees (almost due W) with the rods horizontal (compare with neighbours) - you should be able to see the transmitter clearly in any case.
Also check all your coax plugs, connections, flyleads etc, unplug connectors check for corrosion or other problems and reconnect them. Flyleads are a common problem, try swapping/changing them. See what signal strengths and quality you are getting for the multiplexes (groups of channels) shown in your TV's tuning section.
Problematic connections, water ingress etc. can seem to affect reception of just an individual or several multiplexes.
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Jeni Price:
Hmm, looking at coverage maps, that's not a very good area. Which way is your aerial pointing - North, SouthEast or NorthNorthEast and are the aerial rods vertical or horizontal?
Is there an aerial amplifier/splitter serving more than one TV? If so is it turned on? Is there possibly a mast-head amplifier (that's an amplifier close to the aerial on the mast) and if so does it have a power unit near the TV and is it switched on?
To be able to look at the predicted reception at your location and which transmitter(s) you might be able to receive, we need a full postcode.
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Jeni Price:
The aerial may even be pointing ~SW with the rods horizontal or vertical, there may be two transmitters in that direction. Check which way near neighbours' aerials are pointing.That postcode will be important.
It would also be useful for you to post which UHF channels each multiplex is tuned to, by looking in your TV tuning section, maybe in Manual Tuning or maybe Signal Test or something similar.
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Barry Hardwick:
Yes C48 is as you say very close to 700MHz however this is of no consequence at present. The 700MHz band hasn't even been fully cleared yet, it hasn't been auctioned yet and there are no mobile transmission any where near C48. It will be some considerable time before the frequencies are used, even then you'd need a mobile mast using such frequencies to be very close to you.
David Warner has given a more likely explanation of the reasons you may be having this problem as the Freeview Detailed Coverage Checker suggests that you should have no problems receiving COM6/ArqB from Sandy Heath at your location.
It would be wise to check that your aerial seems intact and pointing in the correct direction and that your downlead looks undamaged (especially if it is old). Also check all your coax plugs, connections, flyleads etc, unplug connectors check for corrosion or other problems and reconnect them. Flyleads are a common problem, try swapping/changing them. See what signal strengths and quality you are getting for the other multiplexes (groups of channels) shown in your TV's tuning section.
Problematic connections, water ingress etc. can seem to affect reception of just an individual or several multiplexes.
Also, just in case, make sure you don't have any HDMI leads near unscreened/poorly screened flyleads/aerial leads as they can cause interference but not normally to channels as low as C48.
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Philip Davies:
There's been no bandwidth "taken away" from Freeview in the way you've put it. All that's happened is that UHF channels used by some transmitters have moved to lower UHF channels. BlaenPlwyf was not affected in this way.
There've been no 700MHz clearance changes to this transmitter, no changes since 2013.
I'd suggest that we don't "give up" at this point. If someone 4 miles away has similar issues, we need to find the "common" reason for this.
Is this friend closer or further away from the transmitter?
It seems to me that there's 3 possibilities to consider. 1) A transmitter fault 2) Some widespread source of interference (yes it is possible) 3) Some problem with your installation that's similar to your friend.
(As far as transmitter problems go, there is Planned Engineering to two of the local relay transmitters listed for this week - Dolybont & Bow Street - both are relays off BlaenPlwyf both within a couple of km of you. Unfortunately the relays do not transmit the COM4/SDN multiplex, otherwise any issue would almost certainly be discovered. But if you happen to see any Arqiva vehicles around you could try asking the engineers if they could possibly check if there is an issue with COM4 at BlaenPlwyf.
To try and find out what's going on, we're going to need some more detail.
When you say your friend has "only Freeview", don't you have "only Freeview"?
You haven't mentioned whether you have any amplifier/splitter for signal to more than one set/box/device.
When you say the programmes are "permanently" pixellated, is this 24/7 or is it only occurring between certain hours? Is your friend finding exactly the same?
How old is your aerial and coax? What about your friend's aerial and coax?
Are you having any problems at all with programmes like Yesterday, Sony Movies, Talking Pictures TV or PBS America?
You said that putting in the new At800 filter caused your COM4 programmes to be worse. As there will be some "insertion loss" with the filter in circuit, this suggests the possibility that the COM4 signal may be weaker than others. Are the programmes Yesterday, Sony Movies etc affected in the same way at all?
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Stuart Swaine:
If you are on a communal aerial, you need to get on to the building management who are responsible.
From some of your more recent comments, it's unclear as to which aerial you are using. You've talked about "your own" as well as this "communal" aerial.
Which way are each of them pointing (compass bearing as accurate as you can be)?
Are the aerial rods vertical or horizontal?
Which way are other aerials in the neighbourhood pointing? Have there been any changes that you can see to other aerials since the 12th February?
In your TV's tuning section, exactly which UHF channels is it tuned to for each multiplex?
You say the HD channels are "up & down", are these numbers 101-105 in the EPG or are you talking about 106/107?
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Maggie:
Did you mean TV or Radio as this is the DAB radio page, but just the same, as StevensOnln1 says.
Do you have Economy 7? That time of night could be when it switches any heating/water heating on, could be a faulty thermostat. When does the signal return?
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Sunday 26 July 2020 10:35PM
michael:
To be a bit more technical, it's not just high pressure by itself, it's what sometimes can go with it - tropospheric ducting - https://www.bbc.co.uk/rec….jpg
I don't recall what the weather was doing mid-February ;)