All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
William Alexander:
I don't think you fully understand the "science" of Tropospheric Ducting etc.
It affects the whole UHF spectrum not just channels 21-48 and a whole lot of the rest of the spectrum including DAB and FM, though ducting is frequency dependant and doesn't necessarily affect them all at the same time nor over the same distances, nor necessarily all multiplexes on one transmitter at the same time, nor necessarily the whole country at any one time.
It depends on current conditions & where the interference at any instance is coming from. That could be from transmitters anywhere in Europe or the UK or even further afield on occasion.
You may not be old enough to know about/have experienced the Band I interference we used to get in the 405 line B&W days that was colloquially called "continental interference". This was due to "Sporadic E" atmospheric conditions (not tropo).
The "sell-off" of the top part of Band V UHF spectrum was part of international agreements across Europe and the rest of Region 1 about the usage of these frequencies, it wasn't a government "decision" as such.
The occurrence of "tropo" has appeared to be more frequent in recent years. It was always more common in summer though can occur at other times as we've experienced. We had a "severe bout" over post Xmas & New year periods in 2019/20.. I suggest that all this may well be associated with climate change.
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JACQUELINE c aDAMS:
Hi. It looks as though you are in the USA and this is a UK Independent Technical Help-site and we are unable to help with such services.
Try Streaming TV Experts & Connected TV Distribution - View TV and look for a contact us page, I can only get a UK one which wouldn't be much help, nor can I find any sensible information about their services at present!
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Luke :
Hi. If that location is very close to Mother Ivy's Bay, then you are about half-way between two transmitters, Caradon Hill to the east of you and Redruth to the SSW. However Caradon Hill is the more powerful transmitter and that location is predicted to get better reception of all 6 multiplexes.
The other disadvantage of Redruth is that is is co-channel for the PSB multiplexes with Wenvoe (across the water near Cardiff) and may give interference problems under adverse conditions, the COM multiplexes are also co-channel with some of Mendip's channels and reception could be variable.
However, you'd need to make sure that the aerial was high enough not to have an obstructed line-of-sight, ie no other caravans directly in the way, or large dense clumps of trees.
For Caradon Hill, your aerial should point at compass bearing 96 degrees (6 degrees S of due E), the rods (or squashed Xs) should be horizontal.
For Redruth, it's compass bearing 205 degrees, that's pretty much SSW, rods horizontal again.
Other than local obstructions, there should be line-of-sight to either transmitter.
Which way do your immediate neighbours point their aerial (which may not be the best of course")?
The UHF channels for Caradon Hill are C28, C25, C22, C21, C24, & C27
& Redruth C41, C44, C47, C48, C33, & C32
both in multiplex order BBCA/PSB1, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6.
You may have to try manual tuning if signals are weak.
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Luke :
As you didn't give a full postcode, I went by the location information that appeared at the bottom of your previous post (but couldn't find a "challaborough bay" which I assumed was a small unmarked bay on the map). At least Bigbury-on-sea now gives a location where I can find "Challaborough Bay".
It's a poor location I'm afraid, and you will probably be lucky to get any Freeview signals and it will depend on your exact location as to which transmitter you might get some weak signals from.
You will need a high gain Group K aerial and possibly a pre-amp (which should have variable gain).
The aerial would be suitable for any transmitter.
As it so happens the two main transmitters are the same - Caradon Hill and Redruth, the direction is obviously different. Predictions by Freeview are poor, the BBC simply say you are unlikely to get reliable reception.
It's 46km from Caradon Hill and is at compass bearing 304 degrees (between WNW and NW).
It's 96km from Redruth and is at compass bearing 266 degrees (almost due W).
Despite the larger distance you might get more reliable signals from Redruth, try it first (without any pre-amp). I don't think Caradon Hill will be any good, but reception from either transmitter is predicted to be poor and you are unlikely to get all the multiplexes (if any!).
Tuning information as as mentioned in my previous post. Good luck.
However - Predictions, especially in difficult locations aren't 100%. The poor reception of the main transmitters is no doubt due to local terrain - being is a slight valley etc.
So having had a quick look on street view, I see that there are some aerials with their rods vertical and appear to be pointing roughly in a westerly direction, so could be getting signals from a relay transmitter possibly on the east cornish coast. As I mentioned in the previous post -
Do the neighbouring caravans have any aerials? Which way do they point?
Often reception over the water can be quite reasonable but may not be stable.
I suggest point your aerial in the same direction as the neighbours (with the rods (or squashed Xs) vertical and as previously mentioned, try Manual tuning but do so working your way up through the UHF channels (starting at 21) and just see what you pick up. Make a note of the channels with the strongest signals.
Post back with how you get on and as much detail as possible, any signal strength and quality figures, as it might be possible to give further comment.
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Luke :
Hi. How far away roughly are we talking for this mast, can you put any name to that part of the coast?
It could be what's called a "self-help" relay which may not be listed anywhere, but I'll try and check some other listings. If it is, and it's an "active" transponder or a transposer, it could have been switched off because of the energy costs at present, it depends on who provides it. If it's there primarily because of the holiday caravans I can't imagine there'll be many there at this time of year, so they may have turned it off.
More detail on it's location may help.
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Luke:
If it's on the corner of the cliff next to the beach (by the coastal path) there's no record of it that I can find. I assume it's not a new mobile phone mast and that TV aerials happen to point in that direction!
In which case it could well be a self-help relay and more than likely the site will have something to do with it.
I think your best bet will be to go and ask Parkdean Resorts what they can tell you about it (I assume they'll have a site office). If not, try asking someone in the Nisa Local store to see if they can tell you anything.
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Luke :
Well done for finding that. mb21 was my next point of call for a search just in case it had anything!
Are you looking at the latest pictures with the new lattice mast from 2021, kit doesn't look quite so home-made!
If this information is correct then it's a transposer, but where does it get it's power?
Quote -
Closeup of receive antenna, from Redruth. Challaborough re-transmits all 6 multiplexes. It is a transposer using channels 49,50,54,55,56,59 VP. 700 MHz clearance has yet to be implemented here.
Interesting, if it still uses those channels? Perhaps you can go have a look for a power source (solar?). Ask around if nothing obvious. Please let us know what you find out.
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Raymond Mitchell:
As you haven't provided a full postcode I can't do any specific checks for your locale. However there is no Planned Engineering or reported Faults that I can find for the Beacon Hill transmitter.
If you still have a problem, do check that your aerial is still intact and p[pointing in the correct direction and that the downlead isn't flapping in the wind.
Check all your coax connections behind your TV. Bad connections, water in the coax etc can sometimes just affection individual multiplexes and not all of them.
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Thursday 2 March 2023 9:42PM
Lionel Campuzano:
There's a reply to your earlier post here Pick +1 | free and easy