Can my aerial and dish share 1 cable?

[damon33]

I apologise in advance if this is posted in the wrong section, but wasn't sure where to put it.
I currently have a satellite dish outside of my bedroom window on a flat roof and would like to add an outside aerial. Is it possible to use the current coax cable that the dish uses or do I need to run another one along my skirting board(I hope not)? I don't mind having to manually switch via some kind of splitter if this is available.
Many thanks
Damon

 

[rolfw]

You can use a diplexer outside and another inside, Global make the units you will need. _http://www.tvlink.co.uk/diplexer.htm

 

[satelliteman]

Yes it can as they operate at different frequencies. You need to use a diplexer & diplexed outlet plate.

 

[michaelcs]

I'm really interested in this thread as tomorrow we are running new cables from the aerial and dish which are situated close together on a roof. I need to get the aerial supply to four different floors of the building, and the dish supply (twin LN to two of those floors.

Was planning to run three completely separate cables, two for the dish (one to each floor that's to have its own receiver) and a third for the aerial cables.

Is this the experts' preferred solution, or would you recommend running

a) one cable, looping in and out at each floor (but how could that work for a twin LNB?)
b) two cables - one straight from dish to main receiving room, and the other with external diplexer on the roof and then down the house looping in/out, with an internal diplexer at each dual face plate (ie 1 external diplexer and 4 internal?) Forgive this absolutely basic ignorance.
c) three cables

I have enough cable for c) and it's a one-off chance to lay the cables I need for futureproofing - but if diplexers work well it's a better/cheaper solution at roughly £7 each....

 

[satelliteman]

@ michaelcs

For the above set up I would:

> Run 4 x cables from the roof to the floors OR rooms first.
> Fit mast head amplifier OR passive 4 way splitter unit depending on 'uhf' signal strength to aerial connection.
> Fit Diplexer units or DIP2's to the rooms where you want 'uhf' & 'IF'
> Connect dish signal to diplexers.

Alternately fit a switch

 

[rolfw]

Yes, don't limit yourself on this initial setup, allow for two satellite feeds in each of the rooms where you require a satellite receiver. I would prefer to keep the aerial feeds separate, but that is a personal choice and diplexing is a perfectly good option.

You can always have a single aerial feed running half way down the building and then use a four way splitter there to distribute to the four floors, obviously a masthead amplifier can be used if you require a higher launch signal.

 

[michaelcs]

This forum is brilliant - ask a complex question and get superfast, intelligent advice from two expert sources. Many thanks to satelliteman and rolfw. :-worship

As I mentioned, this was really urgent as we had an electrician/builder team coming in on the day of your advice. They couldn't get separate cables to each floor as satelliteman suggested, because we can't run that many cables down the front of this conservation area Victorian building - too high, inaccessible, ugly, likely neighbour objections. So they ran three (rather than four) separate cables , one for aerial and one for each of the twin LNB connections, all tucked inside the building, entering from the roof into the top floor at underfloor level. From there (by taking up carpet and two floorboards) to a piping duct that runs vertically beside the staircase. The IFs go only to the two locations where there will currently be sat receivers but it should be possible to link in other rooms later if nec. Not the easiest or cheapest solution but will enable us to rip off a thirty year old tangle of old cables from the stucco front (though we'll have to redecorate the holes etc this leaves behind when scaffolding is next up).

But the ripping-off and switch-over now awaits me doing all the internal fitting of the new cables (which so far are just bare and unconnected) to faceplates, also new diplexes or a booster as needed. This could take a while and depends on the three cables having been labeled correctly .

A few more queries, please, about the aerial and booster(s) for it):

which signal booster is better: masthead or internal (do they require mains feed which would be a problem for the roof?; what kind is best?).

To find out if I need one at all, is it just trial and error or is there a formula, eg do you need one for over so many metres of cable-run (say 30m) or no. of feeds off it (currently 4)?

The aerial, which is atop a very high pole, will have to come down to attach the new cable. We'll mark its alignment with felt tip but we think it's not optimal anyway. Is it best just to use a compass and set it to the bearing of the nearest and strongest transmitter (Crystal Palace, which Wolfbane site shows as being at 148 degrees)? Are there cheap aerial meters or is it just trial and error (roof is a bad location so it would be good to minimise that)? Alignment much less critical than setting up a satellite dish I hope?

Thanks again in advance, guys.

 

[satelliteman]

A few more queries, please, about the aerial and booster(s) for it):
which signal booster is better: masthead or internal (do they require mains feed which would be a problem for the roof?; what kind is best?)

Masthead amplifiers will normally give you a better signal to noise ratio than setback amplifiers as amplification is carried out near the aerial an not further down the line. You may not require amplification if you have adequate levels.

If you do and are using Dip2 diplexers, there is a Dip2-DC version where by the satellite receiver will power the masthead amplifier.

A meter will indicate the signal level received from the aerial.

There are of course other ways of achieving what you want. If you are requiring more satellites feeds then I would go for a multi switch. Lots of info here regarding this.

SM