All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Timothy Davis:
To get more technical, problematic connections etc. can result in what's called standing waves in the cable which are often frequency specific and so affecting one particular frequency more than others.
Major cable breaks will of course have an effect on all signals.
This is why it's a good idea to make a note of the signal strengths and quality of signals for all the multiplexes when your system has no faults, then when there's a problem it can help to identify to possible causes.
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Chris Hargrave:
So BT blaming Freeview, hmm, did they bother to check your predicted reception and/or make any suggestions, sounds not, hardly inspiring for anyone thinking of have BT TV!
OK, lots of possibilities, so eliminating the easier things would be a good start.
Waltham isn't currently listed for Planned Engineering or have any faults that I can find currently listed.
To quickly mention a comment about your query on aerial alignment, yes possible, but as you haven't said where your aerial is, we'll come back to that. Rain can in any event have an effect on the received signals.
With your set-up as is, have a look in the TV and Youview box tuning sections and see what signal strength and quality figures are being given for each multiplex UHF channel, make a note of them.
In the order PSBs1-3, COMs4-7 the UHF channels for Waltham are C32, C34, C35, C29, C37, C31, C55. There's also a Local mux at Waltham on C41, check those are the ones you are tuned to.
Your predicted reception from Waltham is good for the PSBs - BBCA, D3&4, BBCB HD (the same for those 3) but not as good for the COM muxes - SDN, ArqA, ArqB & COM7 and poor/very variable for the Local mux if you can get it.
You might also get very variable PSB signals from Sutton Coldfield which could be within the beamwidth of your aerial or even from Belmont or Sandy Heath on side-lobes of your aerial (all different UHF channels of course).
Also see Channel listings for Industry Professionals | Freeview for which programmes are on which multiplex.
Any significant differences between signal strength and quality for the PSB muxes certainly indicates a problem, I would be expecting D3&4/PSB2 to be lower from what you are reporting, and maybe your TV tuner is more sensitive than the Youview box which is why you don't have a problem on the TV direct.
HDMI leads have been known to cause interference, more commonly with C55 (COM7) but also others, so make sure your HDMI lead is well away from your aerial and any flyleads especially if the aerial and flyleads aren't high quality double screened types.
Plug the aerial lead direct into the TV and check if there's any significant differences with the signal & quality figures with what you get in the normal set-up.
If D3&4/PSB3 is still lower and the relative figures for the others are still the same, then we're looking at an aerial/reception or downlead problem as these checks should have eliminated a local connection or equipment interference problems.
If your aerial is in the loft then alignment can have a noticable effect (as indeed it could externally) due to things like a metal chimney, lead flashing, solar panels, party walls, water tanks and etc. You certainly don't want any of that lot in the signal path or in front of the aerial if at all possible.
Damaged downleads, poor connections, water ingress can also affect particular multiplexes as they can sometimes cause standing waves in the cables and attenuation of some frequencies but not necessarily all frequencies.
Externally, trees near the line of sight can sometimes cause multipath signals, especially when wet, but obviously an external aerial will give problems if there is water ingress into the connections. Aerial alignment could affect an individual multiplex more than others in some circumstances.
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GLEN AYLETT:
As you'll appreciate, there's quite a large area surrounding Canterbury which may be served by a number of transmitters. I can't currently find any reports from the BBC regarding the majority of transmitters in the area, but if its problems with a commercial multiplex, that'll be much more difficult/impossible to track down especially without more specific details of what areas are having the issues. It may have been a brief temporary problem that's now been resolved?
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djlewis:
Retuning when you have no signal is never a good idea, it usually just clears the correct tuning, and you have to repeat a retune when signals are normal.
Whilst it's usually possible to track any reports of recent interruptions to any BBC channels, that's not so for the commercial multiplexes.
There is currently no Planned Engineering at Wenvoe and there are no current Live issues being reported by Freeview.
So try a manual retune on UHF C45 which carries the ArqA/COM multiplex at Wenvoe and hopefully the channels will be restored.
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John McCallum :
It's worth noting that quite a few modern TVs have a built-in satellite tuner, so all you need is a dish and LNB (even an old Sky one, as long as it isn't SkyQ which is not compatible).
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Anthony:
They do try and avoid interruptions at peak times, but it's not always possible.
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Frank Leggett:
As has been mentioned many times around ukfree.tv and for this transmitter on the previous page p92, the site owner has not been able to find time to do all the updates from the 700MHz clearance program as well as correct some errors.
The correct current UHF channels for Whitehawk Hill are in the post Immediately before yours!
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Glen Wood:
Hi Glen. Glad things seem ok at present, let's hope that continues to be the case.
Aerials will primarily receive signals from the direction in which they point but they have what are called side-lobes, generally towards the rear sides where the signals it gets will be weaker.
Hence if the primary transmitter is on reduced power or off-air so you have no signal, a retune might get tuned to another transmitter if the TV receiver has a sensitive enough tuner. Several transmitters are theoretically receivable at your location, so auto-tuning may not be the best of ideas.
The listings at the top of the page whilst mostly correct are not the clearest as the site owner has not found the time to do all the updates for many transmitters from the 700MHz Clearance program and tidy up some errors.
As it's some time and several pages back, I'll repost the list of current UHF channels.
The UHF channels for Belmont in the order BBCA/PSB1, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6, COM7; Local; are as follows -
C22, C25, C28; C30, C23, C26; C55; C32.
The Local multiplex on C32 increased power from 5kW to 10kW on the final clearance. It broadcasts That's Humber (primarily covering Hull and Grimsby areas IIRC).
(Note - Notts TV is broadcast from the Local Multiplex on C27 from the Waltham transmitter NOT Belmont.)
Also note that the auction of the 700MHz frequencies is in progress. Apparently EE are purchasing the "centre frequencies allocated for SDL usage" which is where COM7 transmits. When the auctioning is complete when EE wish to start using the frequencies (they need to develop and install equipment first) then they may give 3 months notice for the closure of COM7 which in any event will close at the end of June 2022 under the current licence.
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Jonathan :
Please see this earlier post and some of the responses All of the free TV channels on PGSTART1450 in the UK | free and easy
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Saturday 13 March 2021 2:45PM
HuwD:
As already mentioned, it's an error. The site owner hasn't been able to find time to do many updates from the 700MHz Clearance program or correct errors like this.
For further information see my post on post Monday, 28 December 2020 on p310.