All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
RMS:
For someone who's been in IT for 40 years, I'm surprised you don't realise that as there's no analogue TV transmitters left in this country, so you've been watching "digital content" since DSO!
If you need a new TV you'll be very lucky to find one that isn't "smart", however there's nothing forcing you to use it in that manner, you do not need to connect it to the internet!
It'll be a good few years yet before the BBC stop "Broadcasting", if indeed they ever do, and if they ever do, then it is more than likely that the other current broadcasters will be doing the same, but then content my be arriving via 5G/6G or whatever exists around that time, as well as over a land based broadband connection. The 3 years that was mentioned was only in relation specifically to some of those "smaller" channels.
Current digital TV broadcasting is licenced until 2034, I doubt very much that it will just stop then!.
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Robert :
I've managed to watch some weather forecasts in between the coverage, and plenty of "other" channels to choose from.
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Robert :
Not before 2034 at the earliest, even then it's not the IBC's decision.
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Daka66:
As you probably know, your main transmitter is Sandy Heath at compass bearing 31 degrees, aerial rods horizontal.
As StevensOnln1 has said there is no Local multiplex there serving your area. Where the small number of main transmitters have Local multiplexes, they are normally beamed to urban centres as mentioned in my post before yours.
Cambridge is served by a Local multiplex transmitted from the Madingley transmitter on UHF channel C35, although its location is likely to be within the beamwidth of your aerial, the signal is not beamed your way.
You stand very little chance of getting any signal from it but it may be worth trying a MANUAL scan on C35, autoscans are very likely to miss a very weak signal.
Whilst StevensOnln1 has said you may get a weak signal for the Oxford Local multiplex, it is virtually in the opposite direction to where your aerial currently points. Some people do receive signals on rear sidelobes of their aerials, so even though it's a very slim chance, try a MANUAL tune on C46.
Other than that, the Oxford transmitter is at compass bearing 255 degrees (again rods horizontal).
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Graham:
The previous posters above do not have the same problem as you. One is so close to the transmitter, even IF it were operating on reduced power (which it isn't) reception would still be fine. That problem sounds like a problem with a distribution system for the flats. The other would not be caused by the transmitter otherwise there would be thousands of complaints and the BBC would certainly have logged a fault as also it would if your issue was related to transmission.
You on the other hand are some distance from the transmitter and if using horizontal polarisation then your predicted reception from Rowridge is not the best for all multiplexes and you could possibly be more likely to be affected by Current Weather conditions - Tropospheric Ducting - causing interference from more distant transmitters in Europe or the UK. This can be very variable and is usually short term at any instant but conditions have been persisting for over a week, different parts of the UK are being affected at different time. Not all multiplexes will be affected at the same time or at all.
Both Freeview and the BBC have issued warnings about short term interference to reception.
Do NOT retune if you have badly pixellated pictures or no signal.
You are correct in that the 20% quality figure seems to be the issue. There are generally two likely causes of this.
One is interference, as just mentioned due to weather conditions. As the interference increases the quality drops until the point the receiver struggles to decode the wanted signal, you get pixellation and eventually the signal will quickly drop to zero as the set sees nothing but noise, or the interfering signal is so strong you start to decode that instead. As the elevation of your locale is quite good, also implied by some predicted reception from the Mendip and Stockland Hill main transmitters, this could make interference more likely in the sort of weather conditions mentioned.
The other, is too much signal which can cause overload of the receiver tuner. As you have mentioned 100% signal (using an amplifier) then this could well be a cause. You may be fine most of the time, but then a marginal increase in signal which can also be caused by the weather conditions mentioned means the quality then starts to drop.
A quick test you can do here, if the amplifier has a gain control, turn it down a bit, say to 95% strength across the multiplexes, you do not need 100% signal. See if the quality returns to 100%.
Or otherwise, unplug the aerial from the amplifier (and switch it off) and connect it directly to your main TV. If the quality returns to 100% but drops again when you reconnect via the amplifier then too much signal is most likely OR the amplifier has gone faulty (less likely if it's giving gain).
Earlier I mentioned your predicted reception using horizontal polarisation. Rowridge is one of very few transmitters that also uses vertical polarisation and your predicted reception for all multiplexes is very good if you have your aerial set with it's rods (or squashed Xs) vertical. BUT you will need to turn the gain down a bit (or add attenuators) if you change to vertical (assuming you aren't already using it).
By the way, your aerial should be pointing at compass bearing 108 degrees, that's 18 degrees south of due E.
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Peter Brown:
This type of error is usually due to the co-ordinates of the transmitter being incorrectly specified and then compounded by some automated geo-location script!
The site owner is the only one who can fix such issues, and as there are some errors in far more significant technical data which the owner has not had time to resolve, this is highly unlikely to get any attention in the foreseeable future.
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I'm getting exactly the same. Problem notified to the site owner, it does sound like some update bug, like a few other problems on the site!
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John H:
As per the top of the page, it means that the actual centre frequency is offset by 166kHz, in this case above. It makes absolutely no difference to tuning by channel as all sets/boxes cope automatically.
The only difference it may make is if you have a device that you tune by frequency eg. some PC cards do that.
If you hover over C22 (or any channel number on this site prefixed by C) it gives you the centre frequency (note NOT C22+ just C22).
BUT frequencies are shown at the top of the page HOWEVER they are rounded to one decimal place ie 0.2 !!
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John H:
Hi John. You always have struggled with COM5 and it is one of the most vulnerable to co-channel interference in your general locale using horizontal polarisation, additionally the COM muxes are lower power in HP than the PSBs, and there has been very variable "Tropo" coming and going across the UK in the last few weeks.
(As an aside, some sets do allow tuning by frequency when using Manual tuning, but in general this won't make any difference, it's those that only allow tuning by frequency where it seems important).
Using the Vertical Polarisation also transmitted from Rowridge, all muxes are at 200kW according to Freeview/DUK, and general predictions for the COM muxes are a lot better, (the data at the top of the page seems to be out of date) even though the COMs are still less reliable than the PSBs in your locale.
Your general locale isn't the best for reception from any of the potential transmitters (dependent on precise postcode & location), however VP from Rowridge is generally the best so unless you are able to get (and want) the Local Southampton mux from Rowridge, you might as well stick to VP now that COM7 has closed. VP should be generally far less vulnerable to CCI from across the Channel.
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Monday 12 September 2022 11:56PM
Ann Kelly:
BBC Local News programmes are available on iPlayer but usually only for 24 hours (much to many people's disgust).
I'm afraid that there's very little any broadcaster can do about weather conditions.
Current Weather conditions are causing Tropospheric Ducting - causing interference from more distant transmitters in Europe or the UK. This can be very variable and is usually short term at any instant but conditions have been persisting on and off for many days, different parts of the UK are being affected at different times. Not all multiplexes will be affected at the same time or at all.
Both Freeview and the BBC have issued warnings about short term interference to reception.
If your tuning was correct, do NOT retune if you have badly pixellated pictures or no signal.
As you have posted on the South Brent transmitter page, if you get your reception from it, your aerial should be pointing at compass bearing 296 degrees, that's 26 degrees North of due West, with its rods (or squashed Xs) vertical.
However you may also get good reception (usually) from Beacon Hill so your aerial would be pointing at compass bearing 82 degrees, that's 8 degrees North of due East, with its rods (or squashed Xs) horizontal.
Whichever way your aerial points, adverse conditions may mean you pickup interference and if you retune then you can get tuned to the wrong signals/transmitter, so it's worth looking in your TV Tuning section to check the UHF channels you are tuned to (C means channel) -
For South Brent (only 3 PSB multiplexes) it's UHF C43, C39, & C46.
For Beacon Hill (all 6 multiplexes) it's UHF C44, C41, C47, C42, C45, & C40
Those are In the multiplex order BBCA/PSB1, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6 (no COMs at South Brent).
See Channel listings for Industry Professionals | Freeview for which channels are carried on which multiplex.
Check your aerial is still pointing correctly, has no missing elements and the coax isn't flapping in the wind. It's also worth considering how old you aerial installation and coax is, older installations may have degraded due to moisture ingress etc. and this can make reception unreliable.