Cabling for satellite

bluebris

I am sick of the crappy service from Chorus so was thinking of putting up a dish and going for FTV/FTA.
There are two standard coax cables running into the current cable access box on the side of the house. One goes up to the TV point upstairs and the other to the main point downstairs.
My question is, can I run two cables from a dish with a double LNB and just connect to the existing cabling or do I have to run new satellite standard coax throught he house (which would be a pain).

Thanks for any help

watty

Run new satellite coax. The Cable company & TV coax is too poor a quality.

I'd go for Quad LNB. Much better value. A Sat PVR uses two coax.

Tony

i'd try the existing first and see do you get away with it, use F double females to join the cables in the service box

bluebris

Thanks Tony.

I'll see how it goes with the existing cable. Too much of a pain to run another set of cabling.

DundalkDuffman

I was just going to ask a very similar question tonight as well, its kinda partly answered now.
I am moving back to Dundalk from the North and cancelling my sky here and getting a new installation in the south. I have ordered up my new freesat from sky cards and 2 ebay'd sky boxes and my quad LNB. I read somewhere that the existing tv points(terrestrial) could be used rather than the installation guy having to run cables all round the house?
It is solely to accommodate watching fta channels in bedroom and computer room, I can do my recording at the main box in the sitting room. Am I missing something in this move that you techie experts would know? Thanks.

byte

Unless the existing cabling is CT100 or equivalent standard, then it is not suitable for satellite.

DundalkDuffman

I see, not getting my new keys for a fortnight so will just have to be in suspenders til then The house was built in 2000 so hopefully it will have this CT100 cabling. Thanks for the help, much appreciated.

stanley1

DundalkDuffman wrote:

I see, not getting my new keys for a fortnight so will just have to be in suspenders til then The house was built in 2000 so hopefully it will have this CT100 cabling. Thanks for the help, much appreciated.

doubt it, most contractors use bog-standard coax.

bluebris

Sorry for being thick. When you say it is not suitable, do you mean it will not work or the signal will be poor.

Thanks

Rippy

DundalkDuffman wrote:

I see, not getting my new keys for a fortnight so will just have to be in suspenders til then The house was built in 2000 so hopefully it will have this CT100 cabling. Thanks for the help, much appreciated.

I have only ever seen CT100 or equivalent cable in a new house when I have been consulted before 1st fix and supplied it to the sparkies.
CT100 cable is always preferred due to it's excellent interference screening and low signal loss characteristics. Wf100 (which is the same only filled with foam rather than air) is the only cable I use for all my installations, satellite and terrestrial.
Most new homes use RG6 cable. This will have a copper centre core, air spaced plastic insulator usually aluminium coated plastic film as a screen and either aluminium or copper braid. It is nowhere near as good as CT100 or WF100, but usually works OK for shortish runs (up to 25 mtrs). If it is preinstalled in a house I will use it, because I have too.
Any old coax cable will 'work' for satellite over a short distance, even old brown tv cable ('low- loss' it used to called , but it's not!). The problem is inadequate screening letting interference from various sources (electrical cabling, mobile phones, DECT phones, microwave ovens, lighting transformers , car and motorbike ignition, etc etc.) into the cable. With analogue tv this can result in line on the picture, with digital satellite (or DTT) it will corrupt the data stream making the pic either freeze or disappear.
So to conclude if you have CT100 or WF100 great, RG6 you are PROBABLY OK, anything less, NO GOOD!

Tony

I get at least one call a week from a householder who says " the electrician has already run the cable" . Usually its terrible Chinese cable labelled as "satellite" cable or worse sometimes. I don't know why people assume that electricians are well up on sat cable specs as they don't have to make it work and are usually long gone when the problem becomes apparent.

Rippy

Tony wrote:

I get at least one call a week from a householder who says " the electrician has already run the cable" . Usually its terrible Chinese cable labelled as "satellite" cable or worse sometimes. I don't know why people assume that electricians are well up on sat cable specs as they don't have to make it work and are usually long gone when the problem becomes apparent.

The next house I see pre-wired with RG59 throughout, I'm going to rip it out the walls , wrap it around a 600mm drill bit, find the f#ck-wit sparky..........:mad: :mad: :mad:

watty

You're lucky if RG6 is not copper plated steel core (OK for RF, but bad for DC LNB power) and plastic/aluminum shield that rots. It's amazing the range of stuff called RG6.

Lack of screening is serious as apart from interference in, the high level Sat IF leaking out can jam everything from 750MHz to 2200MHz. (Depending on 22kHz on/off). Even TV3/TG4 can be affected as the 10.6 LO means lower channels than 11.7GHz are below the 900MHz.

DundalkDuffman

Thanks very much Rippy, thats most informative. Well explained for someone (me!) that has no knowledge of these things at all. Cheers

Sam Radford

I rather like Bill Wright's report here:
http://www.your-book.co.uk/cable.htm

Tony

Great article Sam thanks for the link

byte

Yeah, Bill Wright's article is very good. It's also on his website, where the article looks better.
http://www.wrightsaerials.tv/coaxcablequalityhmdim.htm