coaxial cabling

munklefish · 4 Weeks Ago

Hi,

I live in a block of flats and the cable supplying sky signal to our flat is dead. There is no way to feed a new cable through, but their is a stadard tv coax cable that no longer being used.

Is it possible to disconnect this coax from the terrestrial distributer and feed the sky signal via this?

Obviously there will be issues with the size of the cable being bigger than a normal satellite cble, but is it theoretically feasible?

Any help or suggestions would be appreciated.

Thanks.

**satelliteman** · 4 Weeks Ago

Welcome to the forum,

It's feasible to use standard uhf coaxial but not recommended as this cable is normally only rated upto 1Ghz.

You say it's bigger, also you mention the cable supplying sky signal to your flat is dead. Can you elaborate on this

**nanochickin** · 4 Weeks Ago

Have you considered speaking to the landlord

Most are fairly forthcoming if the system needs attention. This applies if it is owned and you pay a service charge, or if it is rented whether it be a private rent, housing association or council

Nano

munklefish · 4 Weeks Ago

Originally Posted by satelliteman

Welcome to the forum,

It's feasible to use standard uhf coaxial but not recommended as this cable is normally only rated upto 1Ghz.

You say it's bigger, also you mention the cable supplying sky signal to your flat is dead. Can you elaborate on this

The signal can be traced to the cupboard in the communal area, but not from there to my flat. The engineer is suggesting that the only option is to run a new cable from the cupboard to the flat. But, this would involve running the cable through communal areas, out through the wall, along the external wall and into my flat.

This is costly and isnt going down well with the management company since it would have an unwelcomed impact on the communal areas.

So, i was wondering if the signal could be sent down the terrestrial tv ariel, since i dont need the terrestrial signal if i can get sky working again.

**satelliteman** · 4 Weeks Ago

Factors depend on exact cable type, length and general condition.

Earth bonding issues to consider also as this cable probably won't comply.

munklefish · 4 Weeks Ago

Originally Posted by nanochickin

Have you considered speaking to the landlord

Most are fairly forthcoming if the system needs attention. This applies if it is owned and you pay a service charge, or if it is rented whether it be a private rent, housing association or council

Nano

Yes, the problem is due to the construction of the development the cables are trapped in and cant new ones cant be fed through.

munklefish · 4 Weeks Ago

Originally Posted by satelliteman

Factors depend on exact cable type, length and general condition.

Earth bonding issues to consider also as this cable probably won't comply.

So that basically a NO then?? ;-)

**Channel Hopper** · 4 Weeks Ago

The 'larger' cable may be an issue.

Flats in the 70's sometimes had foam based dielectric cable fitted, and the foam has been known to deteriorate over time, leading to a loss at almost all frequencies.

Additionally the distribution system may not be designed so that only your room is fed by that cable, somebody else may lose their TV signals if you poach it for satellite.

munklefish · 4 Weeks Ago

Originally Posted by Channel Hopper

The 'larger' cable may be an issue.

Flats in the 70's sometimes had foam based dielectric cable fitted, and the foam has been known to deteriorate over time, leading to a loss at almost all frequencies.

Additionally the distribution system may not be designed so that only your room is fed by that cable, somebody else may lose their TV signals if you poach it for satellite.

The flats were only built 5 years ago. By larger cable i meant standard terrestrail coaxial is a larger diameter than the Sky cable, isnt it?

The cable is unique to my flat since it comes from a distribution box / splitter in the cupboard at the end of the hall.

**Channel Hopper** · 4 Weeks Ago

Originally Posted by munklefish

The flats were only built 5 years ago. By larger cable i meant standard terrestrail coaxial is a larger diameter than the Sky cable, isnt it?

Might be worth taking a couple of pictures, the cable should be almost exactly the same diameter, unless the installers have installed the shotgun cable for Freesat/Sky.

munklefish · 4 Weeks Ago

Originally Posted by Channel Hopper

Might be worth taking a couple of pictures, the cable should be almost exactly the same diameter, unless the installers have installed the shotgun cable for Freesat/Sky.

Shotgun cable?

Should a typically satellite coax cable be similar in diameter to a typical/standard terrestrial tv coaxial cable?

The existing cabling is only 5yrs old. What are the chances that the terrestrial cable can be disconnected from the terrestrial splitter and used to carry the Satellite cable?

Are there any special considerations to be considered?

Thanks.

**satelliteman** · 4 Weeks Ago

Standard 1mm type coaxial should have an outside diameter of around 6.8mm (TV or sat).
Normally larger type cables are trunk cables feeding taps and splitters, although you say it clearly goes directly to the distribution board.

Why not take a picture and post it up as mentioned and you can have your answer.

Take note regarding using cable that doesn't comply with earth bonding regulations.

munklefish · 4 Weeks Ago

Thanks for the update.

I cant really get a picture since the main cabling is locked away in a service cupbaord, and the bit in my flat is behind a flush mounted wall socket.

What are the earth issues, and what do i need to be aware of?

Thanks again.

**satelliteman** · 4 Weeks Ago

Originally Posted by munklefish

T
What are the earth issues, and what do i need to be aware of?

Thanks again.

Earthing issues would be too complex to discuss here.

You need to be aware that the tampering and modification of any sort to a communal TV reception system should be avoided by un-qualified personnel, full stop

munklefish · 4 Weeks Ago

Originally Posted by satelliteman

Earthing issues would be too complex to discuss here.

You need to be aware that the tampering and modification of any sort to a communal TV reception system should be avoided by un-qualified personnel, full stop

Yes, i know thanks.

Im trying to find a solution since the engineer who diagnosed the problem has so far only come up with running a new cable along the communal corridor, out through the wall, then along the external wall and back into my flat.

This isnt really an option and so im trying to establish if the sky signal could simply be routed via my terrestrial cable, since i wont need this if i can get sky.

**Analoguesat** · 4 Weeks Ago

There is only one way to solve this one way or the other. Someone who knows about flat/hotel type distribution systems NOT a standard installer needs to have a good look at the system.

There is absolutely no way anyone here can give you a definitive answer - no-one apart from you has seen the system in question, and questions about hacking about in distribution systems are well outside the remit of this hobby forum.

You have already been advised several times that disconnecting the terrestrial cable is a really bad idea, for several possible reasons - the answers you will get are not going to change however many times you ask the question.

munklefish · 4 Weeks Ago

Originally Posted by Analoguesat

There is only one way to solve this one way or the other. Someone who knows about flat/hotel type distribution systems NOT a standard installer needs to have a good look at the system.

There is absolutely no way anyone here can give you a definitive answer - no-one apart from you has seen the system in question, and questions about hacking about in distribution systems are well outside the remit of this hobby forum.

You have already been advised several times that disconnecting the terrestrial cable is a really bad idea, for several possible reasons - the answers you will get are not going to change however many times you ask the question.

Blimey! Excuse me for asking.

I am trying to clarify what is being said, since i have very little understanding. Appologies if trying to clarify the situation to make it easier for people to understand, has caused you offence.

**Analoguesat** · 4 Weeks Ago

I was trying to put the replies into context for you as you didnt seem to understand and I thought my summary was quite concise.

As you probably have gathered flat type distribution systems are quite complex things, and not something you can can start disconnecting thingss from willy nilly.

munklefish · 4 Weeks Ago

I did try to make it clear several times that i have no intention of doing anything myself. I have had an engineer whom i dont beleive has offered the best solution since he wants to rtun cables all over the place at great expense.

Therefore i am trying to use a bit of logic to find an alternative solution, hence i am trying to establish if using the terrestrial cable is an option. Regardless of the other implications i am primarily trying to establish if the actual cable itself is theoretically and even technically sufficient to carry the satellite signal, and how feasible this is.

**Analoguesat** · 4 Weeks Ago

Its not possible to answer that without knowing at least:

what type of cable is used,
what its actually connected to,
what the earth bonding situation is...

It might work perfectly, then again it might wreck the terrestrial reception for the entire block, or it could potentially cause a major electrocution hazard for folk in other flats under certain fault conditions!.

munklefish · 4 Weeks Ago

The terrestrail cable is just connected into a multiway splitter/booster box, and can be easily removed. Hence my thinking that it might be possible to hook the cable up to the sky distributer?

**satelliteman** · 4 Weeks Ago

Short and brief.

For example and to expand on what was mentioned in post #20. If you go ahead and use the standard coaxial (assuming that is what it is) ......you could put yourself in danger and others connected to the system. If by any chance a fault developed on the system or drop cable the standard TV coax will not trip the RCD in time and could cause a FIRE !! assuming there is already an earth bond in place.

**Analoguesat** · 4 Weeks Ago

If it is just standard coax it wont work very well anyway - standard coax doesnt carry satellite downlink frequencies very well and results will be poor.

**rolfw** · 4 Weeks Ago

If the flats are only five years old, then there is a possibility that even the UHF feed is double screened, from the sounds of it the cable may be a 1.25mm core or bigger, which would certainly help.

At the end of the day, it is down to getting an engineer who knows his way around IRS installations, as he can test the cable run to see if it is a single point to point run and also whether it will successfully carry an IF signal. He will also be able to ensure that appropriate earth bonding is in place.

We really can't help any more, as this is all guess work, only an onsite inspection by a suitable skilled person can solve your problems

munklefish · 4 Weeks Ago

Originally Posted by rolfw

If the flats are only five years old, then there is a possibility that even the UHF feed is double screened, from the sounds of it the cable may be a 1.25mm core or bigger, which would certainly help.

At the end of the day, it is down to getting an engineer who knows his way around IRS installations, as he can test the cable run to see if it is a single point to point run and also whether it will successfully carry an IF signal. He will also be able to ensure that appropriate earth bonding is in place.

We really can't help any more, as this is all guess work, only an onsite inspection by a suitable skilled person can solve your problems

Thanks for the info. All i was trying to establish was the feasibility of using the terrestrail coax. Now i can suggest that a different -perhaps more competent- installer be called in to investigate further.

Many Thanks.

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coaxial cabling This section is for discussion on domestic multi-receiver systems for distribution of both terrestrial and satellite signals. Multiswitch, diplexer, triplexer, earct bonding, smart Priority switch, signal splitter, SCART doubler, video sender, remote extender, etc.

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