Poor TV reception due to transmitterand engineers

[devonwoody]

Down here in the WCountry we are getting dispruption from engineers and Beacon Hill transmitter.

Would I getter better reception if I used I/Player and other services if I used my PC and router to obtain programs rather than direct from my aerial connection at the present time. I am informed by local tv engineer disruption is likely to continue for some time.?

 

[Trainee neophyte]

Yes, as long as your internet is not as agricultural as your TV. You also get to watch what you want, rather than whatever junk is pushed at you. Go mad and install Kodi, and a new world of free entertainment is at your door.

 

[Eric The Viking]

https://www.bbc.co.uk/reception/news/item234
https://ukfree.tv/transmitters/tv/Beaco ... 0/#pagebar

To answer your question exactly: there was an acknowleged fault on Beacon Hill's Freeview output, some three weeks ago, which is receiving attention. The BBC reference says it affected the HD channels, and doesn't mention the SD ones, implying they are fine. The Freeview site comments also suggest it only affects the HD channels. (aside: Engineers don't intentionally "cause" poor TV reception, they fix it!).

Here is the coverage area:
http://tx.mb21.co.uk/mapsys/map.php?mapid=119
Note the "holes" because of the very hilly terrain. If you are in one of those holes, or close to the edge of one, you might get reception from Beacon Hill on a good day, but it might fail when the weather is unsuitable. It isn't a main transmitter--those would be Stockland Hill (E. Devon) or Caradon Hill (W. Devon & Cornwall), both of which are more powerful. It all depends on which transmitter can be "seen" best from your house.

It's also possible that your own aerial system is marginal. Are you sure you have the correct aerial for the transmitter (group K (grey) or T (white))? Also the condition of the downlead , plugs, etc. can have a big effect on the signal quality. If your aerial goes back to before digital, it almost certainly won't be the best one as the current transmitted frequencies don't match the old analogue ones.

I'd start by finding a good TV aerial specialist (one who actually knows what they are doing and who isn't a cowboy!), and check you're trying to tune-in to the most appropriate transmitter, and that your own aerial kit is in good condition (and the right type). In my experience it is hard to get good aerials. All the DIY sheds only sell wideband ones ("group W"), which, by definition are compromised in performance. A specialist should have the correct ones (either group K or T for Beacon Hill).

You do have another option (as well as using the internet), which is "Freesat" - using a satellite dish to get the Freeview channels. Your aerial chap should be able to advise. There is some cost associated with the kit, and you probably won't be able to use the TV handset to switch channels (you'll get a second one with the Freesat receiver), but the quality can be very good.

By the way, for technical reasons, the BBC regional news programmes (Spotlight and Points West) are not broadcast on the HD channels. ITV uses a different system, so their regional shows ARE on HD. This is the same for both Freesat and Freeview. As far as I know there are no BBC plans to change this. So if you get a caption when Spotlight should be on, this isn't a fault, just the way things are.

There is one drawback to using the internet: "contention ratio". Down the road from your house, either in a green box on the pavement or at the exchange, lots of other people will also be connected to the same pipe. TV and other similar streaming services such as Netflix all need fast internet connection to work well. On a busy evening when there are several popular shows or sports events happening at the same time, you may find your internet connection struggles, and your "reception" is actually a lot worse than off-air. Of course, it may be fine, but you do live in a fairly rural area, so it's probably a fairly narrow pipe to start with!

Hope that's useful,

E.

 

[flying haggis]

cant beat bbc staff for knowing their stuff. well done EtV.

is it possible that pointing the correct group aerial at a relay might be better
this map shows where the Tx is so now we need to know where you are

https://www.aerialsandtv.com/R.JPG

this might help

http://www.macfh.co.uk/JavaJive/AudioVi ... ator.shtml

 

[devonwoody]

Yes thanks Eric, btw our daughter telephoned last night an said “dad get on your you tube and watch Spurs v Liverpool” mind you I did switch off at 3 minutes, that penalty was unfair , the ball was kicked at the player at close range imo to cause the offence, seen using my router and a 40” screen

 

[devonwoody]

cant beat bbc staff for knowing their stuff. well done EtV.

is it possible that pointing the correct group aerial at a relay might be better
this map shows where the Tx is so now we need to know where you are

https://www.aerialsandtv.com/R.JPG

this might help

http://www.macfh.co.uk/JavaJive/AudioVi ... ator.shtml

Post code is tq3 1ex, will that do the job?

 

[flying haggis]

from the postcode it appears that you are 1.93 miles from beacon hill so should get a very good signal as the calculator above gives a line of sight without interuptions.

to use the calculator put your post code in where it asks "where is the receiving aerial" and use the postcode from the drop down box. then use "nearest transmitter" in the next box down, click google map box and it will show where you are with green line to the tx

 

[Eric The Viking]

If you really are less than two miles, the fabled bit of damp string (cut to the correct length!) would do it fine, dangling from the back of the telly. Try not to soak the electrics when you water it...

... seriously, you are very close and, as Flying Haggis says, reception ought to be splendid.

There HAS been work going on at the transmitter, as you said. It's to "make room" for 5G telephony, apparently. That seems to have caused some of the problems, but it also seems that, as of yesterday, they were fixed.

If you are STILL having problems, and the aerial and cable are in good order, there is one final thing to consider: if someone has put up a "normal" sized TV aerial on the roof, the signal strength at that distance might actually be too strong for the telly to cope with.

Surprising but possible: I have a too-strong signal here. I'm not entirely sure how overload of the telly's input stage will manifest itself in what you see (it's not harmful to the telly, just stops it working well), but the fix is cheap. If the web sites say the transmitter is working fine (yet you still get picture problems), try what's known as a "12dB* pad": https://www.ebay.co.uk/itm/151584799108 (AKA "12dB TV aerial attenuator")
It just plugs in the back of the TV and the aerial lead goes into it. There are two types of connector on tellys - the one I linked to is push-fit, and the other sort are threaded. So if you search for "12dB TV aerial attenuator" it will return both types (the difference is pretty obvious!).

You may not need an attenuator (pad), but if the signal is too strong, it's a lot quicker than having to get up to the chimney to swap out the aerial for a smaller one.

Hope this helps and isn't too techy.

E.

*12dB reduces the signal to 1/16th of what it was. Seems like a lot but TVs can usually cope with a good range, and for digits, too-small is slightly preferable to overload. There are smaller values available (each 3dB-worth is a halving of the signal, so 6dB = 1/4 and 9dB = 1/8).

 

[flying haggis]

my thoughts as well with the distance involved (might even get a signal with the aerial unplugged,joke)

 

[devonwoody]

Thanks, we did not have any transmission problems Sunday evening and your news that work had been completed was good news. We did have two electric power cuts at around 5am Sat and Sunday mornings for upto 2 hours so I now suspect tv masts were involved.

So I shall do a channel reinstall and see what the signal strength is now. BTW we are running 3 tellies off one aerial, is that why strength only shews 60% but quality 100%?

(Eric I have only used three of those Phillips head bits over the ten years of that little arrangement we made )

 

[Phil Pascoe]

Going off tack a little, this reminded me of my grandmother many moons ago when TVs were 405 lines. Her neighbour (in an area with appalling reception) with whom she had a love hate relationship had had a massive "H" shaped aerial put up when one afternoon my gran's signal dropped off completely.
It's that ***** next door, she said, she's stolen all my signal.

 

[Eric The Viking]

Thanks, we did not have any transmission problems Sunday evening and your news that work had been completed was good news. We did have two electric power cuts at around 5am Sat and Sunday mornings for upto 2 hours so I now suspect tv masts were involved.

So I shall do a channel reinstall and see what the signal strength is now. BTW we are running 3 tellies off one aerial, is that why strength only shews 60% but quality 100%?

Impossible to say at this distance. Given the signal strength* passive "Y" splitters _ought_ to work, but a far better solution is what's called a distribution amplifier (a "DA", one-in, several-out). Those use a small power supply, usually sited next to one of the TVs, and are powered up that aerial cable. The actual DA can be put anywhere convenient (they usually have waterproof enclosures so can go outside). They're not very expensive either.

The trouble with passive splitters is that the circuit requires all the TVs to be connected all the time: unplugging the aerial lead of one of them will upset the signal for the other two. In a digital world, this can cause a nuisance, or stop reception altogether, depending on the splitter's circuit. A DA isolates each TV aerial from the others, so plugged-in or unplugged makes no difference. Without knowing exactly how your system is arranged one can't tell, really.

My guess though is that, if it was working fine last year, it will be again. As mentioned though, "5G" mobile phones will use parts of the spectrum previously used for TV broadcast**. If you are close to a cellphone mast of some sort, this might be a nuisance in due course, but it remans to be seen what effect it will have. I added a "Tetra" filter to our system here last year. Tetra is the emergency services digital radio system, and it _does_ cause interference. Most DAs are available with built-in filtering but ours are old. We had scaffolding up anyway -- time to replace the aerial... But unless you know there is a Tetra mast near you (and your aerial is looking at it), it's probably not an issue.

E.

*the Effective Radiated Power (ERP) of Beacon Hill is 20kW, which is pretty big, albeit over what is mostly a circle.

Eric I have only used three of those Phillips head bits over the ten years of that little arrangement we made

I have quite a few now, but they do last and last. It's my son's birthday today, and my DiL has bought him a cordless drill/screwdriver. Our contribution will be a set of diamond bits, delivered when my wife goes over to help with the arrival of granddaughter (grandchild #2) in early August.

 

[devonwoody]

Thanks again Eric, I shall wait and see how things go this week, we do have a telephone mast closer than that Beacon Hill tv tower. I believe that causes some problems in the area.

 

[nev]

If I may

Is it possible for the Beebs satellite uplink(?) to be weak or dodgy?

We had a 'weak or no signal' a few days ago on the freesat box but only on a few channels, mainly BBC. My initial suspicions were the tree across the road as it looks like now that it has its full cover of leaves on it may just about be encroaching on the satellite path to our dish (its a tall tree).
Confident enough that was the issue I started investigating freeview boxes to replace my trusty freesat. Luckily I didn't buy one because now the signal strength and quality are back up to what they were previously.

 

[Eric The Viking]

I think it's fed by fibre (because of the satellite lag, amongst other things), but judging by the Google imagery, the site does have a dish, unimpeded by foliage (probably used as the earth station for outside broadcasts, though.

Usually secondary transmitters take their signal off-air from the main station, decode it and send it out again on their own frequencies. They use a high quality RX aerial to get the feed, and usually have line-of-sight to do so. However it's fed, the incoming feed is automatically monitored and the issue seems to have been caused by the work in altering the transmitter channels to accommodate 5G (bottom end of the analogue UHF broadcast band).

DW probably needs to re-scan for the digital services at some stage (I have to do it here, too, sometime this week), as the channels have been (or will shortly be) moved up the band, and, as discussed, the old group A aerials suitable for Beacon Hill in the analogue days will probably no longer serve adequately. Given he's so close, a wideband ("group W") aerial will probably do it though.

Aside: I have a Yagi on the roof, which works well for Mendip here, but digital is much more susceptible to multipath interference than analogue used to be - the smart installers have log-periodic aerials available instead, as those are much better at rejection of unwanted reflections. My next door (party wall) neighbour was having problems with a loft aerial, and I think it was multipath from nearby houses.
- - -
The issue with regional opt-outs (local news, mostly) is that the HD mux (multiplex) is constructed by Arquiva, in London IIRC, and in order to add-in the regions, the signal would have (in this case) to go from Plymouth to London and then back to the Dorset, Devon and Cornwall transmitters. You'd need (very expensive) multiplexing kit actually in Plymouth (and every other regional centre), to assemble the transmitter feed. The BBC has always used London (well, the SE) as a "sustaining feed", from which a region will opt-out. Now, in the digital era, it can actually save money this way, too. ITV just uses time switches automatically (AFAIK there is no national sustaining ITV network, because adverts are local). I think it has the (expensive) kit in place to construct a separate HD feed for each region.

IIRC, BBC Plymouth's studio is actually HD-equipped, but they can only transmit Spotlight live in SD. I think Bristol's Studio A is still only SD though, but I haven't been in the gallery for several years now. In both cases they're only doing regional output nowadays, so the issue is moot unless/until the distribution architecture is changed.

 

[devonwoody]

BTW I have not started a scan yet and I have for 38 years always used a loft aerial in our road.

 

[flying haggis]

DW when you do a rescan, do two, the first with the aerial unplugged, which should show no received channels, then plug the aerial back in and scan again. the first scan effectively clears all the previously stored channels then the second one rebuilds the channel list without duplications. if not done it sometimes causes channels to be added to the list high up in the list ie channel 800 etc as the tv thinks that the new scanned channels are extras

 

[devonwoody]

Thanks for your advice re scan. Going well at moment so not messing. Thanks to all for sorting another one for me, good place to be.