How much gain is worth trying for DVB-T?

[Dave2002]

If a TV set doesn't pick up any worthwhile signal from terrrestrial digital channels in a poor signal area, how much effort can be spent in the hope of getting an acceptable signal? I have been trying to install a TV but it steadfastly shows 0 when doing a scan. This is with a very simple portable aerial with no amplification. If there was anything over 0, I'd try a high gain aerial and perhaps an RF amp as well, but with 0? Is it time to give up?

[Stunsworth]

Buy an amp from Amazon and return it if it doesn’t help?

Portable aerials can be iffy. Do nearby houses have aerials on their roofs? If so that - or a Freesat dish - may be the way to go.

[Bryn]

If a TV set doesn't pick up any worthwhile signal from terrrestrial digital channels in a poor signal area, how much effort can be spent in the hope of getting an acceptable signal? I have been trying to install a TV but it steadfastly shows 0 when doing a scan. This is with a very simple portable aerial with no amplification. If there was anything over 0, I'd try a high gain aerial and perhaps an RF amp as well, but with 0? Is it time to give up?

What does the television reception postcode tool offer?

[Dave2002]

What does the television reception postcode tool offer?

Been there before, but checked again. Suggests good results, but the terrain is a bit random. I climbed into the loft and looked out of a window, and noticed one TV aerial high up on a house maybe 400 yards away. I think the signal levels are way down - definitely not "good" - and it may not be worth investing in new aerials and amps. The neighbours have an aerial in their loft. Just not sure if it's worth the bother - now getting most TV from the internet.

I have got Freesat working after a lot of effort, but the cable runs are long, and I want to get TVs working in another room even further away from the dish. If I could get Freeview working that might be useful.

[Bryn]

Been there before, but checked again. Suggests good results, but the terrain is a bit random. I climbed into the loft and looked out of a window, and noticed one TV aerial high up on a house maybe 400 yards away. I think the signal levels are way down - definitely not "good" - and it may not be worth investing in new aerials and amps. The neighbours have an aerial in their loft. Just not sure if it's worth the bother - now getting most TV from the internet.

I have got Freesat working after a lot of effort, but the cable runs are long, and I want to get TVs working in another room even further away from the dish.

Yes, the postcode tool is only a rough guide. I also get a 'good' result from it but cannot get BBC FOUR HD from either of the recommended transmitters, despite high gain chimney-mounted aerials and amplifier about 3 metres lower, in the loft. The iPlayer is my route to BBC FOUR HD now.

[johnb]

Sorry for stating the obvious but -

Ask your neighbour (who has a TV aerial in the loft) what their reception is like. If it is reasonable then you know that putting a good, directional, properly aligned aerial in the loft or on the roof is a feasible proposition.

There is an online supplier that has a very useful website that is very informative about the products they sell and has very extensive information about aerials, amplifiers, splitters, etc, etc in general: http://www.aerialsandtv.com/index.html

[Dave2002]

johnb

Thanks - though I would still have expected to see a flickr of a signal on the TV I tried. I think my neighbours' reception is OKish - though variable. The TV man I had round said he thought it might be a challenge in this area. I was going to call it a day and put all efforts into satellite and/or internet though it was confirmation from my neighbour that it's possible which put me back on this potential project.

This particular page from the link you gave is definitely of interest - http://www.aerialsandtv.com/awkward-...tallation.html

Presumably if I had some sort of meter I could check a few things out with a bit more certainty. Would something like this one - https://www.amazon.co.uk/d/TV-Antenn...ack/B001GXQUNQ - be likely to show the existence of signals which TVs themselves can't process? In that case it should be possible to calculate the gain required if there is anything of use at all, and such a meter isn't really too expensive. I assume these work with an aerial plugged in to them - never used one myself.

[Dave2002]

What does the television reception postcode tool offer?

The BBC Transmitter checker tool is also of interest - http://www.bbc.co.uk/receptionsearch

It seems to give much more information than the simple postcode checker from digitaluk.

However, it still doesn't help the immediate problem.

[Beresford]

Where I live my car radio in FM scan mode fails to pick up anything.
But if I set the frequency to one I know is being broadcast, from a transmitter that I can actually see from the house, I do get a (sometimes) acceptable signal.

[Anastasius]

Why not get an aerial installer in and see what he says ? He'll have all the measuring kit.

[Dave2002]

Why not get an aerial installer in and see what he (surely s/he) says ? (S/He'll have all the measuring kit.

Probably because of £££s - and finding a good installer. I did call in a TV guy, and paid him £20 for his advice, but he admitted he wasn't an aerial installer, and referred me onwards to others. If I can get a handle on the size of the problem for (say) £30 using cheap measuring kit, then I could decide whether I need to call in another installer. Last time I had a quote from an installer for decent aerials - which was more than 15 years ago (different house), the quote was over £500, whcih was probably reasonable for his work, but with the developments in technology and services we used other methods and did not have that work done. Remember - in those days digital radio was a novelty, DVB-T was only just starting, and digital satellite TV was only just starting to come into use for Freesat, while internet audio and TV streaming was not happening. Digital PVRs for TVs were new around 2005. Having good aerials for radio and TV was always lower priority than any other work which needed to be done in the house.

Nowadays people might have more than one TV and some of them may be large, HD or even UHD. Things have moved on over a decade or two, systems are different, and possibly have more components - multi room operation may be considered desirable. Have we seen the Negroponte switch yet? Perhaps not, but we are in an interim phase. There is (perhaps) still merit in accessing broadcast TV and radio programmes, rather than having all our watching/listening via the internet.

If money is no object then it might be possible to get people in to do this work - but ....

[Anastasius]

£500 ?

Where I live it cost me the princely sum of £130 to have a first-class job done (including aerial and cable etc).

[Dave2002]

£500 ?

Where I live it cost me the princely sum of £130 to have a first-class job done (including aerial and cable etc).

My quote (around 2002/4 - can't remember exactly) was for an FM aerial, a DAB aerial, and IIRC a new TV aerial. I was advised that to get good results we'd have to have a significant mast up on the roof.

I think the installation of a loft aerial for TV and FM radio, with diplexer in a previous house in a different area was well under £100 around 1986, but times have changed. In some areas - such as fringe London areas or neighbouring areas - finding any people to do any (not just radio/TV) work is hard, finding good ones is even harder, and finding good and affordable ones is almost impossible!

[Dave2002]

Now I've got a very faint indication of a signal on a meter - with a portable antenna and no RF amplification, or alternatively with another portable aerial with gain, I can push the reading up to an almost usable level.

I reckon I need at least 20 dB of gain, so perhaps a high gain aerial plus an RF amplifier might pull in enough signal to drive the TV. Oddly what I thought would be a reasonable position in a loft turned out not to be - perhaps because of the house next door - though it's not actually that close, but it might block the line of sight to the transmitter. OTOH I'm not sure that DVB-T is working strictly according to line of sight "rules", because of the way the signals combine from different transmitters, and also because of reflections from the surrounding terrain.

One other thing I'm not sure about. If I can get this working, then the Toshiba "smart" TV should be able to access both Freeview and Freesat. In that case, will it be able to record a channel on either while we watch a programme on the other? Indeed, given that Freeview tuners may very well be software driven (effectively) now, would it be possible to record/watch several programmes on Freeview alone - at least for stations on the same multiplex?

[Anastasius]

Now I've got a very faint indication of a signal on a meter - with a portable antenna and no RF amplification, or alternatively with another portable aerial with gain, I can push the reading up to an almost usable level.

I reckon I need at least 20 dB of gain, so perhaps a high gain aerial plus an RF amplifier might pull in enough signal to drive the TV. Oddly what I thought would be a reasonable position in a loft turned out not to be - perhaps because of the house next door - though it's not actually that close, but it might block the line of sight to the transmitter. OTOH I'm not sure that DVB-T is working strictly according to line of sight "rules", because of the way the signals combine from different transmitters, and also because of reflections from the surrounding terrain.

One other thing I'm not sure about. If I can get this working, then the Toshiba "smart" TV should be able to access both Freeview and Freesat. In that case, will it be able to record a channel on either while we watch a programme on the other? Indeed, given that Freeview tuners may very well be software driven (effectively) now, would it be possible to record/watch several programmes on Freeview alone - at least for stations on the same multiplex?

How on earth do you expect us to answer that ? Unless I missed it elsewhere in the thread, there are a zillion different models of Toshiba TV sets !