All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
R Green:
There is much chatter on the net, some of which you can ignore as it is either pure speculation or comment made without any technical backup or knowledge.
1st, there were no changes to the Sutton Coldfield transmitter around November last year.
2nd, the UHF channels used by the 6 main multiplexes at Sutton Coldfiled have remained the same since the start of DTV.
3rd, Transmission changes over the years have been the addition of the two temporary HD multiplexes COMs 7&8 and a Local multiplex, in Dec.2013, Feb.2014, & Apr.2015 respectively.
4th, The 700MHz clearance changes in Mar.2018 moved COMs 7&8 to UHF C55 & C56 and the Local mux to C36.
5th, Additional transmission of the Local Multiplex was added on C48 in Oct.2019.
6th, Arqiva changed the FEC on COM8 in Feb.2020 to improve resilience of this mux.
7th, COM8 closed at the end of June 2020 for commercial reasons. COM7 will continue for the foreseable future but will close in June 2022 at the latest according to the current OFCOM licence.
8th, Over the years, Commercial Broadcasters have changed the channels they broadcast on Freeview and/or the multiplexes they are on, the most recent of which was July 29th and retunes are usually needed for these. There will be at least one in September.
9th, The 700MHz Clearance Programme in the rest of the UK has now been completed. Sale of the 700MHz frequencies to MNOs for (5G) mobile use is expected to be later this year, but it will be sometime after before any transmissions start from any UK local cells as equipment needs to be installed and handsets available.
10th, Depending on location, to receive all multiplexes from Sutton Coldfield a Group T/Wideband aerial would normally be needed. If reception of COM7 is not predicted/needed, a Group B aerial would normally suffice.
As retunes are periodically needed when Broadcasters make changes, some sets don't always allocate the channels correctly in the the correct LCNs. So if you haven't retuned recently then I'd suggest you do so as follows -
Unplug the aerial and carry out an automatic retune. This should clear memory of previous tuning as nothing will be found. Plug the aerial back in and ideally carry out a manual tune of Sutton Coldfields UHF channels, if you can't manual tune, do an automatic one.
The UHF channels are C43, C46, C40+, C42, C45, C39+, C55 and C48/C36 in the order PSBs1-3, COMs 4-7, Local.
(The + means a 166kHz offsets which TVs do automatically). As you are S of the transmitter, C48 is the one for the Loacl mux. C36 beams N.
The above retune technique doesn't work on some devices such as Youview boxes. For such devices not correctly allocating channels (eg. finding blocks of them in the 790s/800s) a full reset may be needed, but if it's a PVR you may need to reset scheduled recordings.
Did you make any changes to your system/installation around 21st November?
What are the signal strength AND quality figures (or BER if no quality figure) for each of the multiplexes on your TV receiver?
The fact that your DVB recorder is also Guide Plus and is not having problems is not relevant to your set which will have different firmware and the tuner could have a different sensitivity. The fact that the recorder is not having problems is indicative of the fact that there are no problems with transmission!
It's worth considering whether the TV set has too much signal, the figures I've asked for may be indication, don't be confused just because a strength reading might be less than 100%!
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Andy Donaldson:
Hmm. Whilst you are actually predicted to get good reception from Winter Hill for all multiplexes except COM7 which could be quite variable, sometimes poor, you are nevertheless 42km from the transmitter. Are you getting a Local Station (Manchester) at LCN7 in your EPG?
Those latest figures for the HD multiplex are poor. What sort of figures are you getting for the SDN/COM4 multiplex on UHF C29, ArqB/COM6 on C37, and the Local mux on C24?
For which channels are on which multiplex see Channel listings | Freeview
Whilst TV set strength figures aren't definitive, they are a (good) guide and my suspicion is that the aerial I'm afraid sounds very much like a Class 3 and IMHO is not high enough gain considering your distance from the transmitter. The coax I wouldn't have not considered to be low enough loss for a 25m run.
I'm thinking that as it's all only 5 months old, getting the installer back mightbe a consideration, but lets see what the other figures are.
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Andy Donaldson:
Sorry for the typo double negatives about the coax, to be clear IMHO it's not low enough loss, in other words it's not good enough quality for a 25m run (but it's not the worst quality) that coupled with the fact that it's not a high enough gain aerial results in poor signal at the receiver. (Best quality cable would be CT100/WD100 specification).
I should have asked if you were getting a signal for COM7 on C55 and if so what the figures are, I suppose that because the initial concerns with most people on Winter Hill is whether they have old group C/D aerials (doesn't appear you have) but also your prediction for COM7 isn't brilliant. Nevertheless it'd be good to see the figures.
With those figures I can suggest full "informed" comments you can give to the installer - any difficulty with him, you could also talk to your local Trading Standards people.
You can get away with lower quality cable if you have a high enough gain aerial, but the net result of the two should be a signal of minimum strength 45 to 60dBuV at the receiver as measured with a professional signal strength meter - the actual value the installer should be able to physically show you - not just state you've got it.
Higher values can always be attenuated if the need arises.
The only other point I should make is check you coax connectors and cable at the back of the TV to be sure you don't have any broken connections.
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christine gardner:
I'm surprised by two things, the fact that the engineer knew and said it's been going on a "few weeks" - has he not reported it?? I'm also surprised in one way but not in others that "Freeview" said they can't help, they should be quite capable of passing on a report to Arqiva.
Now, to get a bit more certainty about the problem - are your neighbours also getting signals from Cwmafon and are they having the same problems?
If you provide a full postcode I can confirm predicted reception from Cwmafon.
If several of you have the same problem you could always ring Freeview again on 0808-100-0288 the last time I tried to report a transmitter problem I used option 3 (if it's still available), you may have to be a bit "persistent" and even ask for a manager if need be BUT get ALL your neighbours with the problem to phone, it's more difficult for them to ignore several reports.
If you are still bangng your head against a wall, phone ITV, Channel 4, Channel 5 and tell them you can't watch their programmes because your transmitters seems to be faulty and no-one is doing anything about it, can they pass on a complaint to Arqiva (they maintain the transmitters).
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Andy Donaldson:
OK, yes no signal was likely to be expected in the circumstances. That bit of cable is fine, apart from checking connections then, I should have mentioned make sure you don't have any HDMI leads close to your aerial leads as they've been known to cause interference some times especially to C55. So you've got all that you need to have a moan at the installer and tell him that the installation is not good enough and he should sort it out with a decent aerial that'll gives the signal strengths required - you never know you might even get COM7!
What's a particular pain is that there shouldn't have been any real degradation with the final Winter Hill changes, the lower frequencies generally propagate better!
Let us know how it goes, or if you have any further problems /queries.
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Sandra:
What were the circumstances when the problems started? Have you changed anything in your installation, any new equipment?
Have you checked all your coax plug connections, any faulty flyleads coonecting aerial socket to TV or between TV and a DVR etc.? Does your aerial and downlead look intact and is the aerial still pointing in the correct direction?
If you retuned when there was transmitter maintenance or at some point when you had no signal - never a good idea, as all it does is clear correct tuning, then you may be picking up a weaker transmitter.
You could try a retune as follows -
Unplug the aerial and carry out an automatic retune, this should clear memory of previous tuning. Then plug the aerial back in and repeat the retune which will hopefully restore all channels correctly.
Post with more detail of your installation if you are still having problems and a full postcode so we can look at the predicted reception at your location.
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Simon Cole:
BBC 4HD has continued to be transmitted since your posts in 2018, no HD channels were "removed" at the time. I note you did get one rather ignorant response from one poster saying this was due to the "government trying to screw as much as possible from the mobile phone companies for releasing bandwidth" when this is part of a European wide change subject to International agreements - the 700MHz clearance programme - What is 700MHz clearance? | Freeview
Did you speak to the Freeview advice line as advised in 2018?
If you provide a full postcode, we can advise if you are predicted to receive COM7 subject to having the correct aerial.
If you didn't speak to them and if you still have a Group A aerial, then that is why you can't received COM7.
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David Lee:
Really and Dave are on the COM5/ArqA multiplex, see Channel listings | Freeview
Have you also lost Pick LCN11, and other channels on the multiplex ie. Quest Red LCN38, Film 4+1 LCN45 etc.
Do NOT retune if it says No Signal when selecting these channels as it will just clear the correct tuning.
Tell us which transmitter you receive if you are certain which it is, otherwise please provide a full postcode so we can check. It's possible there may be a fault or the transmitter is listed for Planned Engineering.
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Thursday 27 August 2020 5:38AM
S bevan:
If you are receiving Freeview signals you should be able to get 20 channels in SD, and if your receiver has a T2/HD tuner, then 6 channels in HD and 2 more in SD. If you have only 9, something might not be tuned correctly.
BUT exactly how many you should get does depend on location and a full postcode is needed to look at the predicted reception at your location.
Which channels are you curently getting?
Does your TV have an in-built satellite tuner? If so then all you'd need is the Dish, LNB & the cable to get Freesat if you don't have an obstructed view to 28 degrees E.