Digital TV aerial installation etc etc

[SparkyNinja]

Hello all,

I have put an estimate in for a rewire. On the specs sheet from the client it had

'Loft aerial installation to receive digital FM & TV signal'

He requests a TV/FM point to be installed in 4 rooms.
I had originally omitted this from my estimate as it wasn't really something I've done commercially. I'm only used to stuff at home with existing analogue expectations..

Anyway, my client is very keen for me to take the whole job on and his asked me to reconsider if I will be able to do the arial installation etc.

So I'd like to know if anyone has had experience with this work and particularly, how they were able to test the installation.

I believe a wideband aerial is whats needed and have eyed this one up:

http://www.screwfix.com/prods/30515...gs/Labgear-27884LAB-48-Element-Digital-Aerial

As for going to 4 rooms, do I just take 4 cables from the aerial, or daisy chain a couple of runs, or would a booster be needed?

The property will be unoccupied and so would be an ideal occasion for me to gain the experience of this, I just wanna make sure I have the right materials for costing.

All new cable is needed so planned to use PF100.

The client lives a few doors down and has this installed already, and I have checked online and the area is covered for freeview.. apparently.

Any advice would be great.


Many thanks for any feedback.


w

 

[ericmark]

Labgear do a whole range of products and best method will depend on house layout.

With the multi-output mast head amplifiers it can be easier to route all cables outside the house. But the Distribution Amps can combine VHF, UHF and microwave into a single cable. (i.e. Radio, DVB-T and DVB-S)

There are also systems which allow one to re-distribute the Sky (DVB-S) after it has been transverted into an analogue signal so Sky can be viewed in all rooms including reading the remote controller and re-transmitting into sky box.

The aerial may not need to be broad band see here for colour codes.

Much also depends on location and there are sites to tell you the frequency used by each transmitting station.

Not even the boys who fit aerials for a living have all the answers my local guy was telling me how some daft woman wanted to stack aerials and how that would never work. But as a radio ham I know that does work and is used but the length of cable joining aerials becomes critical so not an easy task. So sub-contracting may be no better than you can do.

It can get costly and I use just a simple 6 output amp in the loft as I did not think all these special amps were worth it remembering a free to air sky box is about £40.

Also setting up can be complex to ensure the internally generated analogue signals to not interfere with the received analogue and digital signals and the more complex the system the harder it becomes to set it all up.

 

[EddieM]

Um, you say the client wants a loft aerial. I would strongly suspect that the aerial will need to be outside. Loft aerials are seldom any good.

 

[electronicsuk]

Whatever you do, don't try the 'daisy chain' or 'stick four cables into the aerial and hope for the best' approach, otherwise expect a very disappointed client. As ericmark says, the easiest way to approach this for someone with little experience of TV distribution systems is a simple multi outlet distribution amp ('booster' if you wish) in the loft. If you get one with seperate VHF and UHF inputs then you won't need a diplexer to combine the FM and TV signals. Obviously you will need two antennas to receive these two bands.

As for the oulets, a dual TV/FM outlet at every point with built in diplexer should do the trick. The choice of cable seems fine. You could also do as mentioned and distribute Sky TV via RF around the house, but best not take on too much on your first time! A sensible option would, IMO, be three runs of coax + a phone line to the location of the living room TV, and two to every other outlet. You won't need all of these, but the customer will thank you when they decide that they war Sky+ boxes in every room and a multiswitch in the loft.

 

[ericmark]

I think twin cable is now on the market. To allow for skyHD you need two cables from LNB to box. And if you fit

these to each room with four cables from each to loft next to power outlet then in the future they can connect what they want when they want. Maybe with a

in main room and be honest and say fitting wires and boxes ready makes sense but that the booster splitter boxes come in some many versions that they need to select what electronic units they want rather than you select for them.
That way if a mistake is made with db gain required it is down to them not you all you have done is provide the cable and outlet boxes.

 

[ColJack]

best to conduit from the boxes too to allow for changes to future requirements..

 

[electronicsuk]

I think twin cable is now on the market. To allow for skyHD you need two cables from LNB to box. And if you fit

these to each room with four cables from each to loft next to power outlet then in the future they can connect what they want when they want.

There shouldn't be any need for four cables to one of those plates. Besides the fact it would be a nightmare to fit into anything but the deepest backbox, they usually require two feeds - one carries satellite signals, the other carries triplexed sat, FM and TV.

 

[ban-all-sheds]

It'd be a BGI to flood wire the place with Cat6 (or Cat7 if it's not too pricey - never looked) cable.

You never know..

 

[SparkyNinja]

Well I will be wiring data points to 7 places in the house anyways, so there will be plenty of cat6 to boot.


I think the client doesn't know that a second aerial will needed for the FM, so will have to advise them of that.

So I will price for a wideband aerial which screwfix say is good for loft use, send it to a 2 in/4 out booster. Then send 4 seperate runs straight to the points with diplexers. Then the additional aerial can be installed later if they wish.

I like the idea of the conduit for future alterations, what with sky+HD and all the latest hoo ha. Gonna include that too..

 

[bernardgreen]

So I will price for a wideband aerial which screwfix say is good for loft use, send it to a 2 in/4 out booster. Then send 4 seperate runs straight to the points with diplexers. Then the additional aerial can be installed later if they wish.

Use a distribution amplifier with more outputs than needed at present. They will almost certainly "discover" the need for another outlet some time.

 

[stargazer]

I think the client doesn't know that a second aerial will needed for the FM, so will have to advise them of that.

I have one of these mounted on my chimney and it gives very good coverage throughout the FM band.

 

[EddieM]

Well I will be wiring data points to 7 places in the house anyways, so there will be plenty of cat6 to boot.


I think the client doesn't know that a second aerial will needed for the FM, so will have to advise them of that.

So I will price for a wideband aerial which screwfix say is good for loft use, send it to a 2 in/4 out booster. Then send 4 seperate runs straight to the points with diplexers. Then the additional aerial can be installed later if they wish.

I like the idea of the conduit for future alterations, what with sky+HD and all the latest hoo ha. Gonna include that too..

I still think you should be prepared to install the aerial externally, aerials in the loft in my limited experience do not work very well.

 

[ericmark]

There shouldn't be any need for four cables to one of those plates. Besides the fact it would be a nightmare to fit into anything but the deepest backbox, they usually require two feeds - one carries satellite signals, the other carries triplexed sat, FM and TV.

I was looking to see if three or four cables were required. I did have one of the Labgear distribution boxes which combines the UHF and microwave in loft and splits it again at the face plate. But that was before HD came along and with HD you need two feeds from the LNB to the sky box.

So the main problem is once a room is decorated to add extra cables. I have four cables two microwave from LNB, One feed from aerial and one return to splitter in loft which then feeds all bed rooms with Sky, Free to Sky, DVD, and standard TV signals.

Mine is very simple but I don't have Sky HD so only single feed to Sky box. I will agree you need deep back box. And also maybe you can by using expensive loft box

as shown. But you need the matching plate to split the signals again and at £49 not cheap. A simple active splitter is half the price. And although they will work with Sky+ it says nothing about SkyHD so from our point of view as guy fitting the system we are far safer just fitting cables ready and let the customer select any amps.

 

[aptsys]

I think the client doesn't know that a second aerial will needed for the FM, so will have to advise them of that.

I have one of these mounted on my chimney and it gives very good coverage throughout the FM band.

I wouldn't fit one of those out of choice unless you're right next to the transmitter as they are such a poor design giving a negative gain. At least stick in a half wave dipole.

 

[bernardgreen]

I still think you should be prepared to install the aerial externally, aerials in the loft in my limited experience do not work very well.

If they insist on the aerial being in the loft then wait for a rainy day to install and test. A wet roof reduces the signal compared to a dry roof.