Digital Spy

Search Digital Spy
 

DS Forums

 
 
 

Installing TV Aerial - Existing Wiring Help Needed


Reply
Thread Tools Search this Thread
Old 13-01-2008, 20:35
BCtom
Forum Member
 
Join Date: Dec 2001
Location: Earth
Posts: 1,418

Hi, I have decided to buy an outdoor tv aerial tomorrow. But I need some advice.

I moved into my house in August last year, it was a new build and some tv sockets were already installed in three rooms.
1) living room
2) master bedroom
3) second bedroom

However these cables only ran to the loft where they were just loose and rolled up connected to nothing.

We got sky installed in the living room shortly after moving in and I connected the second sky output to the socket in the living room, put the wires together in the loft and then ran a wire from the master bedroom and second bedroom to tv's in those rooms. This worked perfectly, well almost perfectly, the signal isnt the best.

I have created a quick diagram of the current layout here - click here.

Where can I install the tv aerial so it would work in all the rooms? I was thinking I could possibly run it to the loft but can the coax cable which runs from the living room carrys the signal in the opposite direction.
BCtom is offline   Reply With Quote
Please sign in or register to remove this advertisement.
Old 13-01-2008, 22:26
CWatters
Forum Member
 
Join Date: Jul 2006
Location: 18 miles from Sandy Heath
Posts: 382
1) First off don't just go buy any old TV aerial. There are several different types designed for different situations. Type your full postcode into this site and it will tell you which transmitters you should consider pointing your aerial at and what type of aerial it should be.

http://www.wolfbane.com/cgi-bin/tvd.exe?

Note that local obstructions and other issues may mean the best transmitter/aerial for you is different to that of a neighbour.

If you want learn more about digital TV aerials read this..

http://www.wrightsaerials.tv/digitalterrtvrecep.htm

2) You shouldn't just connect multiple aerial lead together as you did. It frequently works but the signal quality may not be great/the best. The correct approach is to use a distribution amplifier in the loft. Something like one of these...

https://www.blake-uk.com/page/dist_a...tion_proampret

They will take the aerial input and distribute it to all TV outlets.

If you have TWO aerial leads from the loft to the living room then one can be used to send the TV Aerial signal down to the TV and the other can be used to send the output from the sky box back up to the distribution amps where it will also be distributed to the other TVs.

Whichever make you buy get one that supports the Skylink infra-red receiver 'eye'.
CWatters is offline   Reply With Quote
Old 13-01-2008, 22:33
CWatters
Forum Member
 
Join Date: Jul 2006
Location: 18 miles from Sandy Heath
Posts: 382
If you only have one lead from loft to living room...

Does the one from the sat dish go via the loft? If so then there is a solution using one of these distribution amps...

PROception Solo starBOX..

https://www.blake-uk.com/page/amplif...ception_prostr

This particular type can send the signal from the dish AND the TV aerial down ONE wire leaving the other wire free for the output of the skybox to go back upto the loft.

EDIT: Personally if you can I would leave the sky/dish installation alone and run a second wire down from the loft to the living room. Less likely to mess up the sky set up!
CWatters is offline   Reply With Quote
Old 14-01-2008, 07:44
BCtom
Forum Member
 
Join Date: Dec 2001
Location: Earth
Posts: 1,418
Hi, the sky dish doesnt go via the loft. Sky have just ran a cable down the side of my house and through the wall behind the tv.

I have had a look on that UK digital TV reception predictor and the nearest transmitter it recomends a Hi-gain aerial, so I will buy this one from Argos.

I think I will have to just run a cable from the aerial down the the living room as you suggested.

Which of the Multi-way Distribution Amplifiers should I get? 2 way or more?
BCtom is offline   Reply With Quote
Old 14-01-2008, 07:56
Lorien
Forum Member
 
Join Date: Oct 2002
Posts: 1
Personally I'd buy a LoftBox, and some new faceplates. You may need to run one additional cable down to the living room, but it'll be worth it...
Lorien is offline   Reply With Quote
Old 14-01-2008, 12:07
CWatters
Forum Member
 
Join Date: Jul 2006
Location: 18 miles from Sandy Heath
Posts: 382
Yes loftbox is also good. Does same job as the PROception. There are lots of makes. Loftbox has become popular enough that some people refer to all distribution amps as "loft boxes". Bit like all vacuum cleaners being called hovers.

I would go for a model with one or two more outputs than you have TV points for. eg Two bedrooms plus living room plus 1 spare = 4. If you think you might want more go for an 8 way.

I couldn't tell if that Argos aerial was a wide band or grouped? Generally if you can get away with a grouped aerial you get slightly better results than with a wide band but it depends what you need to get both analog and digital recieption. Don't forget to mount it H or V according to the transmitter info.

I gather some digital transmitters are on temporary frequencies and/or lower power output until switch off and will move/improve after that. I expect that will might a few headaches for people who thought they had digital all sorted.
CWatters is offline   Reply With Quote
Old 19-01-2008, 16:25
BCtom
Forum Member
 
Join Date: Dec 2001
Location: Earth
Posts: 1,418
Hi, I have bought my aerial - the one I mentioned above. If I am running a cable from the aerial to the living room and into the sky box. Then the existing cable will run to the loft and then splits between the 2 upstairs rooms do I need the loft box? or will an amplifier do?
BCtom is offline   Reply With Quote
Old 19-01-2008, 16:51
niall campbell
Forum Member
 
Join Date: May 2006
Location: now a townie in glasgow! help
Posts: 6,917
yes you need a distribution amp that will allow sky 9 volt to travel through to allow magic eye to work

there are a few about and this is just an example

http://www.beststuff.co.uk/slx6b.htm
niall campbell is offline   Reply With Quote
Old 19-01-2008, 22:30
AlanO
Forum Member
 
Join Date: Mar 2004
Posts: 1,324
I couldn't tell if that Argos aerial was a wide band or grouped? Generally if you can get away with a grouped aerial you get slightly better results than with a wide band but it depends what you need to get both analog and digital recieption. Don't forget to mount it H or V according to the transmitter info.
All of the aerials Argos sell are Wideband.

It's much less common to see 'banded' aerials nowdays - even Maplin are selling predominantly wideband.

This is because with the introduction of digital, some transmitters are working well outside their original 'Band' e.g. Sandy Heath used to be Group A, but to get digital you need wideband.

Definately go wideband, also because at a point in the future there is likely to be some consolidation of the frequencies used, so there's a chance a transmitter may change from it's current group to a different one. Having a wideband aerial will avoid any future probs.
AlanO is offline   Reply With Quote
Old 19-01-2008, 23:33
CWatters
Forum Member
 
Join Date: Jul 2006
Location: 18 miles from Sandy Heath
Posts: 382
Stores like Argos and maplin only sell wideband because Joe Public hasn't got a clue about groups and in most cases a wideband will work fine.

However if you are trying to pick up a low power mux that's a long way off and at the bottom of the band (group A) then be aware of the disadvantage of a wide band...

Image:
http://www.wrightsaerials.tv/Articles/img/fig%201

Quote:
The forward gain of the wideband and grouped versions of a good quality high-gain aerial. The inferior performance of the wideband version is obvious, with the greatest deficiency being at the bottom of the band. The colours shown correspond to the channel group identification colour.

Performance of wideband aerials
When the DTT signals are outside the analogue channel group a wideband aerial will have to be fitted, but there are pitfalls for the unwary. In ‘attenuator country’ it’s likely to be a doddle – fit a wideband aerial and take the cash. But in districts less well endowed with field strength, the existing array is likely to be a good quality, high gain grouped one. The performance of a wideband array will not be as good as the grouped equivalent. Analogue reception might be visibly degraded, and digital reception could be disappointing.

UHF aerials derive most of their gain and directivity from the fact that they are resonant at the desired frequencies. The lengths of the individual elements are adjusted for resonance, as are the distances between them. The driven element is designed to transfer the collected energy to the feeder most efficiently at the desired frequencies. The wider the bandwidth, the more each factor must be a compromise. Fig 1 (above) shows the forward gain of the grouped and wideband versions of a good quality high gain aerial. It is clear from the graph that where signal strength from a grouped aerial is only just adequate, replacing it with a wideband one is not an option.

We have to accept that wideband reception is now unavoidable in many areas – after all, the multiplexes simply couldn’t be fitted in otherwise – but installers need to familiarise themselves with the performance deficit of the various wideband aerials available, compared to the familiar grouped ones.
CWatters is offline   Reply With Quote
Old 19-01-2008, 23:42
CWatters
Forum Member
 
Join Date: Jul 2006
Location: 18 miles from Sandy Heath
Posts: 382
Hi, I have bought my aerial - the one I mentioned above. If I am running a cable from the aerial to the living room and into the sky box. Then the existing cable will run to the loft and then splits between the 2 upstairs rooms do I need the loft box? or will an amplifier do?
A loft box IS a distribution amplifier.

Using a splitter might work but it's not the professional solution.

Wire from the aerial to the loft box.
Wire from loft box to living room and sky box
Wire from sky box back up to loft box *
Wires from loft box output so two other TVs. *

*=you already have these.
CWatters is offline   Reply With Quote
 
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search

 
Forum Jump


All times are GMT +1. The time now is 04:08.