Q for the Freeview aerial know alls

[Mungo "Two Sheds" Toadfoot]

We have an aerial in the loft running through a booster. Freeview works ok but the sound occasionally drops out for a second, which is annoying.

Firstly, is this likely to be caused by a weak signal or is it just a 'feature' of Freeview?

Secondly, we live in Ramsgate, at an altitude of 50m above sea level, and our transmitter is in Dover. If I blu-tak an aerial to the outside of the house does it really need to be on the chimney or would ten foot up the wall work just as well? There's nothing massive in the way and I'm thinking if the signal makes it all the way into the loft it can't mind a tree or two...

Si

[tony sayer]

In article , Mungo "Two Sheds" Toadfoot scribeth thus

Its not a feature. It might be a signal problem, tested by either swapping the box and/or the TV.

What happens if you remove the booster amplifier?..

As long as there're not that many trees and the aerial is the correct group.. the best way is to fix it up temp fashion and see.

Tho I wouldn't use blu-tak myself;!..

[The Natural Philosopher]

TV feature. If the signal goes, you get massive pixellation and pops and squeaks. Not just a loss of audio.

What counts really is getting rid of obstacles in the near field, particularly obstacles that MOVE. Digital tuners are quite good at fixed multipath, but thy cant cope with e.g. waving trees. Or windmills.

You dont need as MUCH signal for perfect reception as analogue, but you do need more for marginal reception. With digital, its either working, or its effin unwatchable. With analogue is varying degrees of bad.

[Adrian C]

Which freeview box. Wharfedale?

[Andy Burns]

If the video doesn't pause or break-up at the same time then more likely some sort of faulty STB/TV I'd say.

[John Rumm]

Its not a feature of freeview. It suggests the boxes response to an unrecoverable error in data stream. It could be due to low signal, or (more likely in this case) due to interference combined with a low signal.

Different decoders handle errors in different ways. Some get pops, clicks, and squeaks on the audio, better ones will just mute the audio in the absence of having something sensible to produce.

In general, an outside aerial will outperform a loft one. However height can also be significant. So its possible that a reduction in height combined with a move outside could end up with no nett gain. However chances are it will be better.

Using decent screened co-ax and connectors makes a big difference. Also go for a group C/D aerial for Dover, rather than a wideband.

Some more info here:

[Andy Wade]

Some advice here, still valid but ignore reference to the red dot (only relevant to the old OnDigital boxes.

DSO comes to your area the problem will probably disappear because of the increase in transmitter power and the change to 8K modulation.

[Rick Hughes]

if a reception problem, usually get pixilation long before sound is affected.

[Mungo "Two Sheds" Toadfoot]

Good point. We used to watch Sky downstairs but we got rid of that and I threw a tiny s**te old Freeview box that we've had kicking around the spare room for ages into the vacant hole. Having just examined its credentials it says its name is Techwood. Sounds like a decent replacement is on the cards before I go falling off the roof.

Si

[Mungo "Two Sheds" Toadfoot]

Very rarely does the picture show any interference at all, so I believe you're correct. The sound never played up at all when we used Sky so the Freeview box, a tiny silver thing from who-knows-where will be upgraded. Just to see, like.

Si

[Mungo "Two Sheds" Toadfoot]

idea of what goes wrong, what causes it, and how to rectumfry it.

What a spiffing bunch of chaps :o)

Si

[RobertL]

I'm surprised nobody has commented that the aerial is in the loft, not outside on a pole. Surely this is not ideal.

Robert

[Tinkerer]

Just for interess sake, make sure it does not coincide with anything else. I say this because we have two IDTVs (built in Freeview box). The one in the dining room a Toshiba, gets the same brief sound drop as you when the boiler, which is the other side of the wall, kicks in and the one in the front room, a Panasonic, does it when the room thermostat clicks which is nearby. Our previous set did it as well and the thermostat and boiler have both, coincidentally, been replaced in the last few years but it still happens.

[Andy Burns]

Not ideal, but if the video barely ever breaks up it probably good enough and likely to get better after 2012, presumably the O/P is currently on Dover B, being NNE of Dover?

[Mungo "Two Sheds" Toadfoot]

That is interesting actually and I'll bear it in mind. I don't watch a lot of telly but it does seem to drop out a lot all in one go, as it were, then not do it for the rest of the evening.

Si

[The Natural Philosopher]

its a couple of dB at most if it's reasonably sited.

[stuart noble]

My experience of loft aerials is that freeview reception varies between perfect and bloody awful, and doesn't seem to follow any particular pattern. Difficult to test without monitoring if for a full 24 hours I would have thought.

[The Natural Philosopher]

Its less the loft, than what's in it, and what's outside it.

If there isn't TOO much metal around, the losses through the tiles or slates is not too great.

But metal in the near field can do awkward and unpredictable (at least by mere mortals) things to the bandwidth and polar distribution.

[Man at B&Q]

When we first moved into our current house the bedroom TV point was fed from an aerial strung up (literally) in the loft which gave perfect freeview reception.

After replacing the outdoor aerial, mast, cabling and adding a distribution amp to feed 3 sockets, Freeview reception is *worse*.

Unfortunately I dumped the old loft aerial.

MBQ

[tony sayer]

And how many "lofts" you might be "looking through" as well..

Beg to differ. A lot of tiles have Iron Oxide in them and that does clobber the signals. Especially the higher frequencies.

Well thats what BBC research once said, but I can't find the paper at the moment..

Indeed..