Cable for RF and Sat signal combined.

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Bannon

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My Satellite Setup
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I'm soon to be installing a dish - and need to run cable down to the decoder of course, but already have RF cable chased into the wall for the television. To make a neater job I'm wondering if it is possible to somehow join the cable which runs from my aerial to the new cable running from the dish. I would then have just the one cable running down - albeit hosting two signals.

At the socket end behind the television I could then splice the cable into two outputs, one for the RF input to the TV, and one into the satellite decoder. I appreciate the cables feed up to the satellite dish carries a low voltage to the LNB (cannot remember what this is.....9/12v?) but surely this should still work give that each signal is at a different frequency....... or am I getting out of my depth?

It does not seem common or 'accepted practice' in the UK but I'm sure I've seen this done in for example in France especially in new houses where the existing cable is behind say plasterboard - and as said, it would certainly make a neater job.

Cheers.
 
Lots of issues there.

Before you do go any further, you need to know what grade of cable has been installed - one would hope it is a decent quality double-screened type suitable for Satellite use, but if it is cheap and nasty "TV Coax" then it won't do anyway.

I'll leave it to others to deal with combining and decombining UHF and Satellite signals, but you are right in that their are four "flavours" of Satellite signal (High or Low Band; Vertical or Horizontal polarisation) which mean the LNB has to be able to respond to switching signal (change from 13v to 18v and 22 KHz tone) from the Satellite receiver.
 
You can certainly use the same cable for TV and satellite signals but you use the better quality digital satellite cable rather than much lower quality TV grade.

The best for general use is called PF100, WF100 or similar and can be identified by the copper core, foam insulation surrounded by a copper sheath and a copper braid. The cheaper version with aluminium foil (usually called satellite cable) can be used but the all copper version is better.

You need something called a diplexer at the top and bottom to combine the signals and it needs to have a DC path (because the satellite receiver controls the LNB) only for the satellite signals.

It is certainly not unknown in the UK but normal $ly installations are for satellite only.

BTW, this is what I found behind the plasterboard of a French TV cable installation at a friend's house!
 

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Thanks...

I've bought some 'shotgun' cable from a sat supplier. One pair is to be run (from a quad LNB) to a neighbours house for his new Freeview sat decoder, and the other pair I will run back into my loft keeping one as spare in case one of the LNB outputs decides not to work.... rare I've been told it does happen!

The cable seems thinner that the 'normal' cable I've seen - which did surprise me to be honest, but I took that as normal shotgun cable given that I had never seen it before so I'm hoping I'll have no trouble screwing on those F plugs.
 
Bannon said:
Thanks...

I've bought some 'shotgun' cable from a sat supplier. One pair is to be run (from a quad LNB) to a neighbours house for his new Freeview sat decoder, and the other pair I will run back into my loft keeping one as spare in case one of the LNB outputs decides not to work.... rare I've been told it does happen!

The cable seems thinner that the 'normal' cable I've seen - which did surprise me to be honest, but I took that as normal shotgun cable given that I had never seen it before so I'm hoping I'll have no trouble screwing on those F plugs.
Click to expand...

Hi Bannon

you will need smaller f-plugs for the shotgun cable the standard size connector will be no good for you. have a look here the link has been disabled as there is no live links allowed just replace the @ with a h and the start of the link.

@ttp://www.ebay.co.uk/itm/10-x-F-Plug-Connector-Sky-Plus-HD-Shotgun-Twin-Cable-/250699475632?pt=UK_ConEle_SatCableFreeview_RL&hash=item3a5eda6ab0#ht_500wt_1045
 
Is your neighbour's property on the same electrical supply phase as yours?
 
Tivù said:
Is your neighbour's property on the same electrical supply phase as yours?
Click to expand...


I would doubt that Tivu as the phase's are balanced in order to keep the phase rotation in order. this is why in a street with a phase out you will see every third house out in order.
 
It may be in your neck of the woods, but even here in my village, the phase-sharing is done on an entirely different basis.

But even if the method you're familiar with applies, the additional risk is small as all the appliances that will effectively become interconnected should be Class 2 so a single failure shouldn't cause a dangerous condition. Just something that needs to be tucked away in the dark recesses.


But having spent the latter part of my working life responsible for investigating deaths from electrical causes, I always like facts!


Edit: Sorry, the basis is one of grouping. Clutches of adjacent properties on the same phase then another clutch on another phase etc.
 
Ah right Chris thanks - never realised they came in smaller size!

Cheers.
 
You need to be aware that the thin shotgun cable (WF65) has higher loss than the normal size (WF100) and it's recommended that you shouldn't have a run of greater than 30 metres. Not usually a problem but you might live in a three storey Victorian house!
 
Hi Paul, some more advice please?

I've now run in my cable from the dish and now need to pair it with the RF cable from my aerial - what sort of connector do I need? Presumably I can change the RF plug to an F plug leaving me with with F inputs to a device giving two outputs.

At the business end behind the TV I have an RF/Fplug socket which I'll just link together. None of this is 'good practice' I know but hopefully it will work and save me having to chase out the wall or surface mount another cable.

Cheers mate.
 
PaulR said:
You need to be aware that the thin shotgun cable (WF65) has higher loss than the normal size (WF100) and it's recommended that you shouldn't have a run of greater than 30 metres. Not usually a problem but you might live in a three storey Victorian house!
Click to expand...

Agreed, was furious when the Sky engineer ripped out my good cable for his low quality shotgun cable. We called them because the box was faulty but he insisted on replacing the dish and cable too as well as moaning on at "what a bloody mess" my motorised dish was.
 
You could use a diplexer or triplexer of the type use in the living room but just connected the other way round. Something like this perhaps _http://www.toolstation.com/shop/Electrical/TV+Satellite/Screened+Triplexed/d190/sd3084/p14718 - just ignore the FM socket.

There are diplexers available which look similar to this _http://www.toolstation.com/shop/Electrical/TV+Satellite/Wideband+TV+Satellite+Splitter+2+Way/d190/sd3084/p66100 but the one shown is NOT suitable as it is a splitter, not a diplexer. If you get hold of one (I don't know where from BTW) it will specifically say diplexer on it and give the frequency band delivered to the ports.
 
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