Bad reception on freeview

[Paul_Sengupta]

The other thing, what are the connections like at the back of the telly? My parents had a problem with reception on their kitchen telly which came and went. There was an aerial lead which came in through the window frame and terminated on a small box inside. From there a patch lead took it to the telly. Anyway, when you moved the telly or the lead, the signal would come and go. I had a look, and something inside the box was loose. My dad had suspected the box and had bought another one. However when I tried to fit it, the screw holes were slightly different and it didn't cover the paint in the same way, so I had a look to see what was wrong with the old one. It had a loose connection where the terminal met the board inside. I soldered it back and all was well.

[cotterpot]

(I don't have an iphone, would you believe )

There are compass widgets on android

[Sharpie]

Connections ont' telly were the first thing I checked! In the past the scart lead had worked itself slightly loose ..
Best approach now I think is to have a good session with the tuner. If there were a connections issue I don't think that I would get what I have now - a pretty good signal (70%) but the tuner is grabbing only BBC channels.

If that doesn't bear fruit then it has to be a intermittent connection fault, an unusual occurrence but weather in the mast connections could cause that.. must get hold of an ammeter, thought I had one but can't find it...

[Sharpie]

Telly has been working fine last couple of days (dentist syndrome?) but I needed to check it all out so today I got up on to the roof with the help of a handy friend, all connections were OK but redid them anyway, re-orientated ariel to 271. Cables all good.
Signal strength is about 75% although quality is down at 35%.
So I tried retuning but for the life of me I couldn't get it to register any stations from Oxford at all. Tried all the mux, 53, 60, 62, 59, 55. It scans and then says no stations registered. But I am getting them from the Sandy transmitter, despite the ariel orientation. Tried it on two tellys, same thing on each. I would rather have Oxford as it's more my area. Any ideas?

[Ian Melville]

Hi Sharpie,
I had poor signals problems a few months back and found that it was the splitter/Amp that was the issue. Despite all the signs that it was working OK the signal was pixelating with changes in the weather. Bypass the amp so the feed only goes to one TV and see what happens.

The trouble with a digital signal is that there is no gradual deterioration. It only takes a small signal change to go from perfect image to bad, or none at all.

[Keef]

You should be getting multiplexes from Oxford on channels 53+, 55, 57, 59-, 60-, and 62. If you're not, maybe you are "over the horizon" from the Oxford transmitter. What does the map say? The Oxford aerial is 295m above datum. Sandy is 291m so there's not a lot in it.
The coverage map for Oxford shows that you are close to the edge, and there are some blank spots from Oxford around Halton Wood and Hengrave Wood. Sandy shows coverage well beyond you, so it may be down to terrain.

If it won't find the stations on the Oxford transmitter, then point the pesky thing at Sandy and see what you get. If that autotunes correctly and gives you the full set with a good signal, then I'd blame hills. Sandy muxes are on channels 21+, 24, 27, 48, 51 and 52.

Otherwise it comes back to aerials. Oxford's muxes are all at the high end of the spectrum (above 700 MHz) whereas Sandy has some down in the 500 MHz band. If you have an older "lowband" aerial, that could be part of the problem - it would manage the BBC and ITV main channels from Sandy, but would struggle with ITV3 and beyond and others such as Dave, and all the Oxford channels.

When we had our roof done, I fitted a DY14WB from this source - it was well worth it, because we have a rock-solid picture on all the muxes and SWMBO is very happy. It's a wideband aerial, so will cover everything from 500 to 800 MHz. I was tempted to put a rotator on it so that I could point it at different stations - I did, for a brief experiment with it fixed to the scaffolding before the tilers put it up on the chimney for me. That proved that there was only one transmitter that I could receive anyway, so it points at that, +/- a degree or so. The rotator is waiting to go on my VHF and UHF amateur aerials come the spring.

[Keef]

PS: agree with Ian. If you have a booster amplifier and it's not boosting, then the splitter on the output of it will degrade the signal seriously.
Bypassing it may give an indication.

[Sharpie]

Thanks chaps, useful thoughts.
Tied up with seasonal events now, will get on it after hols.
Cheers!

[Paul_Sengupta]

When I first bought myself a freeview HD PVR box I eagerly looked forward to watching some HD. I plugged it all in and set the tuner scanning. After it had finished, I looked for the HD channels. There were none. So on the internet I go, look up the Guildford transmitter (relay) and find that it wasn't broadcasting HD! Argh! So I bought a new higher gain wideband aerial and pointed it at Crystal Palace. That's still where I get my picture from. My aerial is (are, I have two up there now!) in the attic so it's not so much hassle to change.

But yes, I'd bypass the amplifier first to see what happens.

[Keef]

Two aerials is a good wheeze: I ended up with two at the Essex pad. They were messing around with digital changeover and turning down the power on analogue from Bluebell Hill. We were, technically, out of range of Crystal Palace but I installed a high-gain wideband aerial and 24dB booster, and pointed it at CP. The PVR box had two aerial inputs and did the clever stuff combining them - it worked very well.

[chevvron]

In recent weeks, we've had a momentary interruption of signal when a Heathrow departure goes over; we get our signal from CP and we're on the MID departure route. Takes me back to the 60s when this happened with any aircraft on analogue TV.

[chevvron]

We have 2 digital TVs (19" in the kitchen and 22" in the dining room) plus a 26" analogue fed from a Thomson TopUp Tv box in the lounge. I've done re-scans on all three and the 2 digitals come up with 147 channels whilst the Thomson box comes up with 152. More significantly, the 'box says it detects 11 multiplexes when I think there should only be 6. We're almost directly on a straight line joining CP and Hannington so I can only assume we're picking up some 'southern' channels - they appear to be mostly BBC duplicates both TV and radio. It could of course, be Paul's Guildford relay, but I doubt it as my aerial is horizontal polarisation.

[Keef]

Some sets will update with "new" muxes found, but don't dump the old ones that have disappeared. The result is a mess - I get very cross with one or two devices here when they end up with two of every station after a "retune". I've now got the instructions written down for "wipe the lot and start again".

The PVR is clever enough to pick the strongest mux for each station, use that, and then sort them into the same order that's in the Programme Guide.

You may be picking up stuff off the back of the aerial - it happens.

[chevvron]

You may be picking up stuff off the back of the aerial - it happens.

Yes from Hannington, that's what I suspected.

[Paul_Sengupta]

http://www.diynot.com/forums/audio-visual/unexpected-way-to-solve-tv-freeview-reception-problem.299354/

In a last effort to trace the problem, before I considered getting the TV itself checked out, I switched off the amplifier and the splitter, and reset the TV. Surprisingly, it found a few digital channels. I then entirely removed the amplifier and the splitter from the aerial cable run to ground floor level, and reset the TV. It found ALL the digital channels, with perfect reception!! Problem solved.