All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
keith batt:
It is never advised to retune when you have no/very weak signals or/pixellated pictures if you were correctly tuned in the first place as this very often just clears your correct tuning.
There has been some quite strong tropospheric ducting/temperature inversion periodically affecting large parts of the UK in recent days. Retuning means you can end up tuned to some distant transmitter whose signals disappear as conditions change. You then have to retune again, which you may have to try several times as you won't know when the signals are normal! Not all multiplexes will be affected, it depends on where the interference is coming from as it can be very frequency dependant.
As you haven't given a full postcode, we can't advise if there are other specific issues that may affect reception in your area. Have you checked that your aerial still looks intact and is pointing correctly?
Have you checked all your coax plugs and connections behind your TV?
Make sure that you don't have any HDMI cables running close to your aerial cables.
Have you ever received a postcard from restoretv.uk ?
Your best bet may be to find which multiplexes you are currently missing, see
Channel listings for Industry Professionals | Freeview for which TV channels are carried on which multiplex and then manually retune the relevant UHF channel for the Oxford transmitter.
Note, if you normally receive the Local multiplex (depends on location) Oxford uses 2 UHF channels C22 & C46 which are beamed in different directions and which you get (if either) will depend on location.
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Marc:
If you use bad language your post will be filtered by the automatic software on this site.
As you haven't given a full postcode, we can't advise if reception of some other multiuplexes from another transmitter may be possible. There are parts of your area that can receive other transmitters.
If you have a Smart TV and a reasonable internet connection, it's possible to stream quite a few of the other channels for free.
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nick:
Hi Nick, sorry, I had seen it and meant to find a couple of articles for you to read, got side-tracked and forgot :(
In essence, all the elements are active but "tuned" to different frequencies.
The Wiki article gives a good basic understanding as does the article from Don Valley Aerials.
Log-periodic antenna - Wikipedia
The log periodic | Don Valley Aerials
There's a BBC R&D article which I haven't has time to read but will no doubt be interesting -
A UHF log-periodic receiving aerial - BBC R&D
As you'll see, and has previously been mentioned, you can produce a log-periodic for whatever frequency range you want.
So still available from some suppliers is the original UHF Band IV/V wideband or Group T which are now getting more difficult to find as they aren't needed any more for UK transmissions, and there's few continental transmitters yet to clear 700MHz
More readily available now is a Group K (21-48) and a Group A (21-37). I don't recall seeing a specific Group B one, little point really as Group K will do the job.
Hope that helps. If I find anything else of specific interest, I'll post it.
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Andrew Smith:
Steve Donaldson has given you a very comprehensive reply which suggests that since DSO you should be able to get reception from the Wells next the Sea (Norfolk, England) Freeview Light transmitter | free and easy transmitter, however we'd need your full postcode to see a bit of a more accurate prediction. As mentioned trees etc can be a nuisance if on the line of sight! You may even be able to get reception from Tacolneston but it could be variable
The Freeview predictor suggests that generally you may get good reception of the BBCA multiplex from the Wells transmitter but the BBCB HD and D3&4 multiplexes may be a bit more variable.
Have a look at your nearest neighbours' TV aerials to see which way they are pointing and if pointing easterly with the rods (or squashed Xs) vertical, ask them about their reception.
You may be able to get away with an aerial combiner with an aerial pointing at Belmont and the other at the Wells transmitter but you should consult a local (experienced) aerial installer that knows your area (ideally one recommended).
If, as your post maybe suggests, your existing aerial is that old, it and it's coax downlead may well have significantly degraded which will affect reliability of reception, but also you should note two things at present
1) There has been quite variable weather related Tropospheric Ducting in recent days which can affect reception because of interference being received from more distant transmitters in Europe or the UK - not all multiplexes are necessarily affected
2) As noted in the post before your first, the Belmont transmitter is subject toe Planned Engineering at the moment with Possible effect on TV reception as Pixelation or flickering on some or all channels (that could include loss of signal).
The other option you might be able to consider is Freesat. A lot of modern TVs have a built-in satellite tuner so all you'd need is the Dish and LNB.
Finally, as far as Flood Risk and Warnings, you should get signed up to Floodline, see -
Sign up for flood warnings - GOV.UK
HTH.
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ALAN ASTON:
As you haven't given any indication of how long this has been happening, it's difficult to say!
As per the post before yours, the transmitter is subject to Planned Engineering which may be the reason.
There has been quite variable weather related Tropospheric Ducting in recent days which can affect reception because of interference being received from more distant transmitters in Europe or the UK - not all multiplexes are necessarily affected.
You may normally have problems with co-channel interference on C25 but as you haven't given a full postcode, it's impossible to comment on that.
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ALAN ASTON:
Just to add, if your aerial is pointing in a southerly direction, the Preseli transmitter may be receivable within its beamwidth, so you could try a manual tune of C42 for the SDN multiplex, but reception may be variable.
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Jim:
Hi Jim. We haven't moved anything as this is an independent technical helpsite.
The history here is unclear. Angel Vintage as it is now known may have been on the original Trial Woking multiplex which was a single transmitter. It seems that changed a while ago to "Trial Aldershot" when there was a 2nd transmitter added at BFBS Aldershot.
I'm not sure whether Angel Vintage was ever on the "Trial Aldershot" multiplex, but it seems it should be on the "Surrey & North Sussex" multiplex Block 10C: 213.360 MHz which should cover your area, check you are tuned to that multiplex.
http://www.muxco.com/wp-c….jpg
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Jim:
Ah, I think we have discovered what's happened - Angel used to transmit in Mono which would have been receivable on any DAB Radio. But they have recently changed transmission mode to DAB+ which means it will only be receivable on radios that have DAB+ ability, your two Roberts may be older than DAB+ but worth checking with the manufacturer as some radios have the ability to have a software/firmware update.
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Gino:
Even though Winter Hill is still listed for Planned Engineering and you are some 63km from it, you are predicted to get a good signal on all 6 main multiplexes.
Now, there has been some quite variable weather related Tropospheric Ducting in recent days which can affect reception because of interference being received from more distant transmitters in Europe or the UK - not all multiplexes are necessarily affected, but this isn't normally sustained for any lengthy periods, nor is there normally any lengthy interruptions to transmission during engineering and even if they are on reduced power for a while, you should still be receiving signals.
Did you perchance Retune at any point when you may have had no signal for a short while either due to Interference or Engineering? If so this very often clears your correct tuning. It's not advised to retune when you have no signal or badly pixellated pictures if you were initially correctly tuned.
If you did, and you don't know if your tuning has been cleared, your best best will be to do a Manual tune for Winter Hill's UHF channels.
They are C32, C34, C35, C29, C31, & C37 that's in multiplex order -
BBCA/PSB1, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6
You may also get the G-MAN Local mux on C27 and a choice of L-MAN on C24 (Manchester local news) or L-LIV on C21 (Liverpool local news)
See Channel listings for Industry Professionals | Freeview for which TV Channels (LCNs) are carried on which multiplex.
If you are finding your problem persisting, check your aerial looks intact and is pointing correctly, that the downlead looks undamaged and isn't flapping in the wind, that you haven't lost power to any amps/splitters etc. and all you coax plugs are inserted correctly. Check if a near neighbour has the same problem. Then post back with more detail of your aerial installation and things you've checked/tried.
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Tuesday 13 June 2023 1:26PM
Mel Broom: & bruce:
And do NOT retune when you have no signal or pixellated pictures as this usually just clears your correct tuning. If you have retuned, you'll have to repeat it, maybe several times as you won't know when your signals will be normal.
In addition to which, there is also some variable weather related Tropospheric Ducting causing interference to wanted signals from distant transmitters.