All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Matthew Delaforce:
The Planned Engineering is mentioned on this site. Although you have posted on the DAB page, there is a note at the top of the page about the Engineering and the possible effect on Freeview. On the Freeview transmitter page, apart from the note at the top of that page, there are several posts about the Engineering work which has been going on and off for several weeks, similarly to a lot of other main transmitters.
As you haven't given a full postcode, it's not possible to comment on your predicted reception and make any constructive comment on how yours may be impacted by the engineering., and additionally whether you may be subject to any interference.
Arqiva never give details of the engineering work, or how long it may last as quite a lot of it can be weather dependant and you cannot work at height on masts in very windy conditions nor close to the antenna at full power. Some tasks cannot be carried out in the rain.
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Guy de Jonquieres:
It's also worth pointing out that you are surrounded by a lot of mobile phone masts. If you are missing other channels, you may be missing a complete multiplex, which may be due to mobile mast interference.
See Channel listings for Industry Professionals | Freeview for which TV channels are carried on which multiplex.
You should have received a postcard from Restore TV, you can put your postcode in at
https://restoretv.uk/post…ure/ to check.
If you find that your are missing complete multiplexes or have reduced signal but especially reduced Quality which should always be 100% (check in your TV tuning section), then you may be advised to contact Restore TV for a Free Filter.
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Paul Dursley:
Hi Paul. I'm surprised none of your neighbours watch the Freeview HD channels (if they have aerials pointing at Backwell, and you can't be that much of a luddite if you have an HD TV :)
You could certainly contemplate two aerials BUT you cannot just "splice" the two cables together, they need to be combined properly - these days usually by using a splitter in reverse AND it would need to be a low insertion loss splitter (I'll comment more later). Whilst I don't think I'd be concerned about the Wenvoe signal, you Backwell one may not be quite strong enough, so either a bit of experimentation is needed or some professional checking with a proper professional signal strength meter.
You might not need an aerial pointing at Wenvoe if the signal received of the side of the Backwell aerial is strong enough, as you no doubt have done, you can manually tune the Wenvoe channels you want.
Something else I've not asked, is the TV the only thing connected to the wallplate or does the signal route via a PVR/VHS recorder or similar?
If yes, and the latter, does it have an RF output and what channel is it set to (even if you don't use the RF)?
If you have any HDMI cables, keep them as far away as possible from aerial cables as they have been known to cause interference.
If the signal does route via other equipment, check the signal strength and quality of the multiplexes and then plug the aerial direct to the TV and repeat the measurements.
How many elements (rods & dipole and grid(?) does your aerial have?
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Jan Knights:
Is your small TV connected to the communal aerial as well?
Roughly how many TV channels do you get on your main TV, is it below 50 or over a 100? (This gives us an idea which transmitter the communal aerial is pointing at) - unless you know which way it points!
If it points to the High Wycombe Relay transmitter (Downley - the closest) roughly compass direction WNW it's UHF channels 37, 31 and 32.
If it points roughly SSE at the Chepping Wycombe Relay transmitter, it's UHF channels 40,43, and 46.
If your small TV doesn't have HD capability for the HD TV channels, ignore UHF C32 or C46.
If the communal aerial points at the main Crystal Palace transmitter roughly ESE and you get over 100 channels on your main TV then it's UHF channels 23, 26, 30, 25, 22, 28, and 35. If the set isn't HD capable ignore C30.
The UHF channels numbers are in the multiplex order BBCA/PSB!, D3&4/PSB2, BBCB HD/PSB3, SDN/COM4, ArqA/COM5, ArqB/COM6 and the Local multiplex. Relays only have the PSB multiplexes.
See Channel listings for Industry Professionals | Freeview for which TV channels are carried on which multiplex.
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Jackie Hone:
A lot of main transmitters have been having extensive Planned Engineering in recent times. It's over 10 years since DSO and no doubt to ensure that the transmitters and masts continue to give reliable service for another decade such work is needed. In addition to which the Mendip mast is a similar construction to the Bilsdale mast that was destroyed by fire in August 2021, so I'd expect some of the work would be to try and ensure that fate didn't happen at Mendip.
Most of the service area is receiving normal signals, you may be in a weaker reception area BUT as you haven't given a full postcode, we can't check that or check if you might be vulnerable to mobile mast interference.
It is worth emphasising, as already mentioned by StevensOnln1, assuming you were correctly tuned, anyone should NOT retune if you have no signal or bad pixellation, whether it's due to a fault, weather conditions or engineering. You cannot tune to signals that are not there or can't be decoded.
I assume that you have checked that your aerial still looks intact and is still pointing correctly after recent severe weather, and that the downlead isn't flapping in the wind,
If you've lost your correct tuning, your best option is to clear memory of any incorrect tuning - by unplugging the aerial and doing a full automatic retune which should clear memory as no signals should be found.
Then plug the aerial back in and do a MANUAL retune for UHF channels 30, 32, 33, 34, 35, 36 and 48.
You may not receive C30, the Local multiplex, as it's beamed towards Bristol and you may not be in that reception area.
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Paul Dursley:
This is the sort of splitter you need, not the cheap ones with a plastic body -
https://www.screwfix.com/…4534
if you have a Screwfix within easy reach, Or for example -
eBay item number:37223707416 OR eBay item number:276418817108
BUT unless you've got another device to connect to the 2nd port you may have a mismatch which could introduce misleading figures.
You'd be better experimenting with an attenuator. And having had a look around I see there are some real rip-off prices being charged for say a 3dB coax attenuator, so unless your local TV/aerial shop has one real cheap, I'd suggest you get one of these, plenty of scope for experimenting -
Close
OR eBay item number:330646460117
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Paul Dursley:
Apologies that Screwfix item may be the wrong connectors but worth a look as I know they got descriptions wrong before. It looks correct with coax, I missed the description.
https://www.screwfix.com/…4534
BUT the description mentions F-connectors. There are others, if it is the wrong type.
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Paul Dursley:
Sorry, I'm not doing very well today! I think I'll go back to bed!!
The first eBay attenuator number has a digit missing, it should be item number 372237074168
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Sunday 14 April 2024 3:39PM
Paul Dursley:
What I'm not certain of, is how effectively the BBC monitor Relay transmitters such as Backwell. Whilst it looks as though it's an off-air feed from Mendip, that could be just a backup now and it could be line fed or microwave link fed, many Relay transmitters have had links updated in recent times, but that doesn't seem to fit with what has been experienced.
The usual source of such information is sites like mb21 where the question has been asked by someone in the past and the information added to the site.
Out of curiosity, have you asked any neighbours if they found a similar/same problem?
Did you manage to have a look at the condition of your coax?
It's worth remembering that there's always the possibility of degradation of your aerial installation - detail not yet discovered, especially as you mentioned variations with weather (which of course could still be a transmitter issue).
If you aerial is a standard Yagi type, such as similar in appearance to -
https://www.blake-uk.com/aerials-tv-yagi/10-element-contract-pcb-balun-group-k-channels-2148.html maybe with a bigger grid and/or longer OR
https://www.blake-uk.com/aerials-tv-yagi/13-ele9-dir-dig-contract-grp-t-f-type-std-s-caiab162-channels-2160.html
then the gain of these aerials drops with the lower channel numbers, so you'd get less signal, and if it was marginal for some reason (a fault on the installation - eg. ingress of rain, later drying out) this might explain the issue.
If at some future date, you find an issue or decide to replace your aerial installation, then I'd consider something like a Group K Log periodic which will have a flat response across the channels Such as -
https://www.blake-uk.com/aerials-tv-log/28-element-log-periodic-group-k-aerial.html
or if higher gain is needed -
https://www.blake-uk.com/aerials-tv-log/56-element-log-periodic-group-k-aerial-new-double-element-design.html
There are some other manufacturers of Group K Log periodic.
What you certainly don't want is a replacement that is a wideband aerial of any type as this leaves you more vulnerable to possible mobile cell interference, should there be more new/upgraded masts in the future (quite possible). Group K is UHF C21-C48. No TV transmitter in the UK uses any channels above C48 which is now for mobile use.
A decent aerial installer should be able to provided such an aerial and install with quality double screened coax.