TV aerial cut close to wall

[strumpusplunket]

Okay. We moved into our new house about a week ago, and soon found that the previous occupants had most helpfully cut the TV aerial cable extremely close to the wall. Thanks guys!

You can see how close it's been cut, and how little cable there is to play with in the attached picture:

There's not enough space to add a standard male coaxial connector. All I've been able to do so far is strip back a bit of cable and attach the inner part of the coax connector and connect it to our freeview box via a female-female connector and a short coax extension cable.

Obviously, this is far from ideal and it's a very delicate connection. Look at it funny and it comes loose. Unsurprisingly. My wife is less than happy with this piece of my handiwork...

Is there anything I can do other than go through the faff of having to drill through the (extremely thick) external wall and thread the cable through where there'll be more to play with? As you can see it comes in at a corner, so I couldn't fit a wall plate either, I don't think. Are any of the various type of cable repair kits able to do anything with such a tiny bit of cable?

Any advice would be most gratefully received.

Cheers.

 

[Prubs]

Try this http://www.maplin.co.uk/balun-300-75andohm-5145

 

[strumpusplunket]

Hmm. So, just so I get this straight: the screw fittings at the bottom of that device screw directly onto the bare copper in the coax? Bit puzzled why there seem to be two inputs though (if that's what they are), and also flummoxed by this talk of using a "short piece of 300ohm feeder". I'm a bit of a novice when it comes to AV issues like this, I'm afraid...

 

[Prubs]

Yep that's right. as you said you do not have a lot of cable to play with, so this is probably going to be your best bet

 

[Orionaut]

What a mess!

How hard would it be to rewire it back to the aerial?

If they cocked it up at this end, the other end might not be too good either!

(A TV cable is essentially a pipe for HF radio waves (Borderline between conductor and wave-guide)! Unfortunately it is also a pretty good pipe for water! If the other end has been done badly you will end up with a TV full of water! Ask me how I know! )

 

[strumpusplunket]

Yep that's right. as you said you do not have a lot of cable to play with, so this is probably going to be your best bet

Yeah, it looks like it would fit at least. I'd only be using one of the two screw-thread inputs though, is that an issue? (I've only just started Googling baluns since I've never heard of one before)

What a mess!

How hard would it be to rewire it back to the aerial?

If they cocked it up at this end, the other end might not be too good either!

(A TV cable is essentially a pipe for HF radio waves (Borderline between conductor and wave-guide)! Unfortunately it is also a pretty good pipe for water! If the other end has been done badly you will end up with a TV full of water! Ask me how I know! )

Actually, the aerial end is all very nicely done. The aerial sits in the loft rafters, and there's a booster box with a few outputs coming out the back wall and pinned to the wall for reception in different rooms.

The kitchen and bedrooms still have good cables, but the place we want it most, the living room, has been cut to the wall (there are box Sky and Virgin inputs so I guess the previous occupants just saw the aerial as useless and cut it back). The previous occupants were tenants, and my guess is the previous owners fitted the loft booster box and then when they let the house the tenants cut the aerial back (just guessing, though).

Edit: but as for the question of how hard it would be to rewire back to the aerial - a huge hassle! It would actually be easier I think just to drill another hole, but I do want to avoid that if possible.

 

[PistolPete]

How is adding a 300ohm balun to a 75ohm feeder going to help??

 

[Prubs]

or you could do as Orionaut has said. Probably would be best to start afresh

 

[strumpusplunket]

How is adding a 300ohm balun to a 75ohm feeder going to help??

Yeah, I have to admit, I'm puzzled here. I've still no real idea what a balun is for or why I'd want one other than it looks like it might fit and make a connection?

or you could do as Orionaut has said. Probably would be best to start afresh

Agh, no! That would involve high ladders (higher ones than we own, certainly), pulling up the loft insulation to find the cable route, pulling one of four cables from the batch and refitting... just way too much hassle!

Drilling through the wall would be preferable, and the cable itself is fine as far as my inspections can ascertain. Would still like to avoid that, though, if possible...

 

[Participant]

First thing I'd try, which I presume you already have but I'll say it anyway, is get some pliers and give it a mighty big yank. There's bound to be some slack upstream.

Then I'd probably look into digging some of the plaster out on the right hand wall and fitting a wall plate thusly:



The higher position should allow the required slack. Is it plasterboard on that side? What happens to the cable behind the scenes?

 

[strumpusplunket]

First thing I'd try, which I presume you already have but I'll say it anyway, is get some pliers and give it a mighty big yank. There's bound to be some slack upstream.

Then I'd probably look into digging some of the plaster out on the right hand wall and fitting a wall plate thusly:



The higher position should allow the required slack. Is it plasterboard on that side? What happens to the cable behind the scenes?

Yeah, you're right. I did try that, but I couldn't get any slack from it. But now I think of it, there might be some slack further up the wall. There's definitely slack where it comes out of the loft, but it's pinned tightly to the wall all the way down so it doesn't give by pulling from inside. But I might be able to wheedle a bit more by pulling it through the exterior wall fixings from outside. Hmmm. I wonder. Never thought of that until now. Cheers. I'll try that over the next day or so.

The plate is not a bad idea either. Easier to drill on this side near the door frame, but no, it's not plaster, but brick. This room is on the corner of the front part of the house, with external walls behind the aerial and to the left of it. Could still be done, though, I guess?

Edit: the cable comes straight through from outside. It's pinned to the wall all the way straight down from the loft and then horizontally along the top of the french windows and down the wall again to the entry point.

 

[mattyy]

First thing I'd try, which I presume you already have but I'll say it anyway, is get some pliers and give it a mighty big yank. There's bound to be some slack upstream.

Then I'd probably look into digging some of the plaster out on the right hand wall and fitting a wall plate thusly:



The higher position should allow the required slack. Is it plasterboard on that side? What happens to the cable behind the scenes?

I would chase a bit of the wall out, wack a 25mm back box on and then use a plate as suggested. You might find if you have enough room for what you have done then the plate may fit on already.
Chasing it would probably be easier than drilling again and re running it.

 

[visibleman]

If this is your property then i'd do it properly - once the existing coax has been unpinned you should be able to tape a new length to the end of the existing cable and drag it through (and then finish it properly with a box in the wall).

If it's rented, then i'd see if you can replace the the current RF plug with an f-connector which will give you a far better connection (with it being a screw-fit connector). Then you just need to knock up a F-connector to RF cable and use a f-connector coupler.

 

[strumpusplunket]

I would chase a bit of the wall out, wack a 25mm back box on and then use a plate as suggested. You might find if you have enough room for what you have done then the plate may fit on already.
Chasing it would probably be easier than drilling again and re running it.

If this is your property then i'd do it properly - once the existing coax has been unpinned you should be able to tape a new length to the end of the existing cable and drag it through (and then finish it properly with a box in the wall).

If it's rented, then i'd see if you can replace the the current RF plug with an f-connector which will give you a far better connection (with it being a screw-fit connector). Then you just need to knock up a F-connector to RF cable and use a f-connector coupler.

Thanks. Both interesting ideas. It is our house yes. The previous owner rented it, but we bought it from her.

Chasing some wall out and leaving the cable in its current ingress is an interesting suggestion. I've been and checked again and I really can't decide if it would be enough or not. It probably would, tbf, but give how deep I'd need to chase out to to fit a back box and how much dust that would create, wouldn't that actually be quite a big job compared to rerouting the cable a little higher?

Visibleman, I'm not quite sure I get what you're saying, but that's likely just because I'm a bit of a noob at AV stuff. Are you suggesting adding new cable to the outside of the house and then dragging it through? I'm a bit nervous of water ingress if doing that.

If I do decide to drill through the wall to the left of the French windows (which is probably the best location) the wall is 25cm thick. Could I do that with a normal hammer drill if I buy a long enough bit, or do I need a special type of drill for that? If I can't quite manage Participant's suggestion of routing the cable in a little higher on the right hand side I may try that if it's doable.

EDIT: Oh, wait a minute, Visibleman... are you suggesting there might be enough cable as is to fit an F connector?! I've never fitted one before, but just assumed that since I couldn't get a normal RF plug on I wouldn't be able to fit an F connector either. If I could do that I might just take the lazy route, fit the F connector, screw in an extension cable and pin it up around the inside edge of the French windows. (I'm never one to make more work for myself that absolutely necessary...)

 

[visibleman]

Does this cable go outside and back in again at loft level (ie - seems a bit bodgy to me)?

As for pulling new cable through, do exactly that - tape a new length (usually end one of a reel) to the exist cable and pull the existing cable at the other end until the new cabling is pulled through.
I've done it a few times with coax that's buried in brickwork and whilst it's a bit of a PITA it does work (eventually). If it's plasterboard then it'll be a PoP. And similarly if the cable goes outside and back in, it should just be a case of ripping the old cable out and using the existing holes through the brickwork.

The f-connector idea, it's just a temporary solution (as it'll still look a mess) and you'd need to strip the cable (obviously use what you've already stripped) a bit more for a male type connector - it'll be tight but should be doable.
Tbh, f-connectors should be used where ever possible now as they provide a far better connection that RF connections (most aerial/distribution gear now is fitted with f-connectors).

Alternatively, get the duct/electrical tape out and tape up what you have, that'll stop it becoming loose. Again, a complete bodge job but it'll work.


You just need a half decent masonry drill bit if you're wanting to go through brickwork. Just make sure you're drilling at a slight angle (from outside in, you want to angle upwards a tad) to prevent water getting and then fill it up with exterior silicon once the cabling is pushed through.

 

[terminator2k2]

is it possible to screw a f connector onto the bit that's left? then use a f coupler and another f connector onto some new coax ?

 

[strumpusplunket]

Thanks for all the replies here.

In the end I had a bit of a brainwave. There is a Sky TV lead that we're not using coming out right behind the TV, and it's a shorter distance for the aerial cable to go.

So, a simple matter of pulling out the old cable clips, pulling the Sky leads out of the wall and and rerouting the aerial cable to the now empty hole. Easy.

And... ta-dah! Quite a bit more cable to play with:

(Yes, it's a mess there at the moment. We've only been moved in two weeks...)

Result!

Or it would be... but I seem to have a bigger problem now.

No TV reception at all. Not a single Freeview channel found by either the BT box or the TV's inbuilt Freeview tuner.

This seems odd because there was some reception before I rerouted the cable: 29 channels, BBC very flaky, but I'd put this down to the dodgy connection.

Now, a proper RF plug on the end and... zip!

Possible causes?

From visual inspection I can't see any cable damage other than this, which I noticed when pulling out a cable clip:

Would that be enough to explain this?

Also the cable now crosses over at right angles the Sky cables, but I can't imagine that would do anything, would it?

This is becoming a severe PITA...

 

[Participant]

Not sure what that is. Has someone put some sleeving over the cable to cover up a split or something?

Have you connected the plug to the cable properly? No contact between the braiding and the centre core?

 

[strumpusplunket]

No, it's just the coax. No sleeve. What's there in the second picture is just some damage to the cable itself. It looks superficial, but I guess it might have damaged the screening or the interior insulation and thus degrade the signal?

As for the plug connection - I have checked and double-checked and I'm as sure as I can be that the it's connected soundly. Definitely no braiding touching the inner wire. There's a good 1/2cm of dielectric plastic left between the end of the outer cut where the braiding wraps back around the outer sleeve and the inner wire.

Think I'm going to have to assume some cable damage somewhere. I guess moving the cable could have just been enough to break the connection, open a crack in the screening or whatever.

<Sigh> This has been so difficult, and I never even foresaw the TV connection as a job to get done in the new house. Oh well. I guess I'll see next if I can drag through/extend one of the working aerial cables...

 

[strumpusplunket]

Okay, final update.

Found that the kitchen aerial gave good reception, and came down the outside of the house the same way before going off on its long journey round the back. Snipped it about three metres down the line, rerouted it into the living room and... nothing.

Checked the RF plug. Changed the connector. Still nothing. On a last whim went to the kitchen, took the RF plug apart from there and noticed a slightly different inner plug (no screw like the other two had). Swapped this for the one in the lounge, and... 90-odd channels perfect picture.

So, was it damage to the original lounge aerial cable, or just two crap RF plug assemblies? Or both/combination of these? Guess I'll never know now.

At least it's working now, though.

Thanks to everyone who came in with advice.