TV aerial cables

[MooseInAshbourne]

Hi Everyone.

I wondered if you could help. In August I moved into a new build house. Many rooms had AV sockets, typically one F-type (I guess for satellite ) and one traditional Co-ax for Terrestrial TV.
In the loft there were 8 or so cables in two bundles (probably one budle of four for sat, one budle for TV).

There was no aerial, so I installed one in the loft and pointed it at the Butlers Lane transmitter. When I connected the aerial directly into the back of the TV with a single co-ax cable (via the small amp that came with the aerial) I tuned the TV and got about 200 Terrestrial cahnnels. Sweet.

The problem came when I plugged the TV into the socket in the Lounge, and connected the cables in the loft to the aerial. I tried all the loft cables, but none of them seem to be connected to the socket in the lounge: i.e. there little or no signal picked up by the TV.

I'd appricate any advice as I am not an expert in this sort of thing.
Cheers,
Rob

 

[mikej]

How does the number of outlets in the house compare with the number of cables in the loft ? Do you have 4 rooms with a Freeview and satellite outlet in each room to match the 8 cables in the loft ? Check all appropriate rooms (lounge, dining room, kitchen, bedrooms etc) carefully and look out for any larger rooms that may have two sets of outlets on opposite sides of the room.

Carefully take the faceplate of the lounge outlet and check the coax is connected correctly behind it.

Can you pick up a signal in any of the other rooms ?

 

[mikej]

It would also be worth checking the signal strengths when the TV is connected directly to the aerial - there's normally an option for this in the tuning menu.

 

[Rodders53]

Barkers Lane more usually known as Sutton Coldfield transmitter.
Where, roughly, are you receiving from?

Photos of the sockets in the rooms front and back might help?
Ditto of the cables in the bundles. Any markings? Decent cable has makers idents/specs on the outer sheath. Some sparks will cut nicks in the insulation, or use marker pens, to number /identify the different ones (others couldn't care less).

Exactly what aerial and amplifier is being used (make and model / link to the device(s) please)?

Most likely is a termination issue... stray whisker of outer screen touching the inner somewhere. Unless really awful coax cable has been used.
Wiring up plugs, aerials and wall plates - A.T.V. Poles, Brackets, Clamps & Aerials may help with that, perhaps?

 

[MooseInAshbourne]

Hi Mike, thanks for your reply. There are four sockets in the lounge, two co-ax and two F type.
None of them seem to work.
The study has two, again, 1 co-ax and one F type.
Bedroom is the same, but I've not tried them, the TV is to big to carry around. Is there a way of testing the continuity of the cables in the wall?

I have checked one baase plate, it looks OK. I'll get some photos.

 

[Rodders53]

https://uk.rs-online.com/web/p/network-test-measurement-accessories/1466832 could save a lot of time for a pro installer and do the job properly?

Most will use a multimeter on ohms range to detect an imposed inner-outer short on an outlet socket and find which cable is shorted in the loft (and mark it with a 'flag' of masking tape or similar.

 

[MooseInAshbourne]

Thanks Rodders. I'm in Ashbourne, Derbyshire. I know I can recieve from the transmitter because it works really well when I connect an arial directly into the back of the TV.

I have a Labgear Log Aerial :

Labgear LOG Aerial

Order online at Screwfix.com. Wide band aerials with built-in amplifier in a single output. Compact design. Supplied with power supply and kit. FREE next day delivery available, free collection in 5 minutes.

www.screwfix.com

I'll take some photos and come back.

 

[mikej]

From what you've said so far, it sounds to me like the fault has to lie with the coax cable and associated plugs, the aerial outlet, the fly-lead used to connect the outlet to the TV or a combination of some or all those.

For starters, the coax run would obviously have to be continuous. A severed cable is certainly possible although less likely in a new-build I would have thought, especially when compared to an older house that's been subjected to many decades of DIY ! But if neither of the lounge sockets work, then the chances of a severed cable being the cause is pretty low, IMO.

I would take off and inspect the plug (termination) at the end of the cable in the loft to check it's been done properly and that there are no stray strands touching something they shouldn't (as mentioned above). If you can't easily identify the correct cable, then you might have to be prepared to inspect all of them. Do the same with the aerial outlet sockets and check they have been wired up correctly, as it's possible that a builder connected them rather than an electrician or aerial installer !

As for the fly lead, make sure it's of decent quality. Many of the cheap cables can be pretty poor quality so one option is to buy a more premium, ready-made cable or make your own out of a length of good quality coax and a couple of plugs. While this may not be the sole cause of your problem, this will help to ensure you get the best signal strength possible to the TV.

 

[MooseInAshbourne]

From what you've said so far, it sounds to me like the fault has to lie with the coax cable and associated plugs, the aerial outlet, the fly-lead used to connect the outlet to the TV or a combination of some or all those.

For starters, the coax run would obviously have to be continuous. A severed cable is certainly possible although less likely in a new-build I would have thought, especially when compared to an older house that's been subjected to many decades of DIY ! But if neither of the lounge sockets work, then the chances of a severed cable being the cause is pretty low, IMO.

I would take off and inspect the plug (termination) at the end of the cable in the loft to check it's been done properly and that there are no stray strands touching something they shouldn't (as mentioned above). If you can't easily identify the correct cable, then you might have to be prepared to inspect all of them. Do the same with the aerial outlet sockets and check they have been wired up correctly, as it's possible that a builder connected them rather than an electrician or aerial installer !

As for the fly lead, make sure it's of decent quality. Many of the cheap cables can be pretty poor quality so one option is to buy a more premium, ready-made cable or make your own out of a length of good quality coax and a couple of plugs. While this may not be the sole cause of your problem, this will help to ensure you get the best signal strength possible to the TV.

Brilliant thanks. The Fly lead is OK, I used it to connect directly from the aerial to the TV, I got about 100 channels.
I will check the continuity of the cables, see if any of them are connected to the sockets.
Then I will inspect the termination on each of the cables in the loft.
Thanks alot for your help!

 

[Rodders53]

DE6 1EU postcode (a pub in the Town): Wolfbane predicts 34 dBuV/m outside @10m, diffracted.
The Ashbourne relay of Waltham is predicted at 93 dBuV/m being so near.
DE6 1DD Redrow Homes is 52 dB line of sight and 106dB for the relay.
Other new developments seem to be on that South/Southeast side of the town centre?

TVs need 45-65 to work well.
That aerial - according to labgear has a gain of 6dB (ref a dipole = as expected) plus another 16dB for the amplifier. That needs DC continuity on the cable between the aerial and the Power supply unit output with no 'blocking capacitors' as sometimes appear on UHF wallplates.

I'd fully expect that relay to be received on a bit of wire hanging out the back of the TV... although foil backed insulation and plasterboard will kill radio signals quite effectively?

So most likely issue is the one of dodgy terminations as you've tried the sat F-sockets which are usually direct connected (or triplex filtered) and have DC continuity as a consequence {needed for LNB power}.

 

[MooseInAshbourne]

DE6 1EU postcode (a pub in the Town): Wolfbane predicts 34 dBuV/m outside @10m, diffracted.
The Ashbourne relay of Waltham is predicted at 93 dBuV/m being so near.
DE6 1DD Redrow Homes is 52 dB line of sight and 106dB for the relay.
Other new developments seem to be on that South/Southeast side of the town centre?

TVs need 45-65 to work well.
That aerial - according to labgear has a gain of 6dB (ref a dipole = as expected) plus another 16dB for the amplifier. That needs DC continuity on the cable between the aerial and the Power supply unit output with no 'blocking capacitors' as sometimes appear on UHF wallplates.

I'd fully expect that relay to be received on a bit of wire hanging out the back of the TV... although foil backed insulation and plasterboard will kill radio signals quite effectively?

So most likely issue is the one of dodgy terminations as you've tried the sat F-sockets which are usually direct connected (or triplex filtered) and have DC continuity as a consequence {needed for LNB power}.

Yes, I can pick up a few channels with just a cable out the back of the TV. The Ashbourne aerial only has 8 channels.
My house is on the Redrow develpment on the south side of Ashbourne on a hill. I'm pretty sure my aerial can see Butlers Lane (Sutton Coldfield) when it is mounted in the loft as I have had over 100 channels.

What do you think of this to check the continuity? Then I would be able to check which socket matches each cable in the loft:

Amazon product

 

[Rodders53]

That device does have some adapters to sort of do the job. But a simple multimeter is cheaper, used on the resistance range. e.g. LAP AC/DC Digital Multimeter 600V and could have other uses around the home in future.

EDIT
Ashbourne transmits 45 channels (less 16 radio, 5 duplicated in HD and 1 iPTV delivered) so 23. So only getting 8 on the TV is odd.
SC has a lot more of course.
Local news via Waltham/Ashbourne is E.Mids (Nottingham) from BBC vs SC Mids news from the Mailbox in Birmingham.

 

[MooseInAshbourne]

I have a multi-meter but I don't have a cable long enough to reach from the loft to the TV to check for continuity.

 

[Rodders53]

Check first that all present an open circuit between inner and outer cores...

Then introduce a short on one outlet at a time to 'find' that cable with the multimeter. Label it.
Repeat.

OR (having checked for shorts, get a battery and wire +ve to the centre core and -ve to the outer (maybe using a plug/socket?) and then use the meter to find the 12/9/1.5 V of the battery at the cable end / socket. That's basically all those testers do (with a resistor in series to prevent an issue if the cable is short circuit) by lighting an led.

EDIT: You have the aerial amplifier PSU that will (via adapter plugs if needed) supply the 12V signal up the cable to loft.... DOH

Breaks in cables installed are incredibly rare and even then RF will usually 'jump' the tiny gap in a centre core wire, so it works for RF but not for DC.

 

[MooseInAshbourne]

Thanks to you both. I bought a cable checker, labeled the 8 cables in the loft, labelled the 8 sockets and worked out which was connected to whcih.
There are still two Aerial sockets that do not seem to be connected, but I found the cables that the four F type sockets in the lounge are connected to.
Using the cable that came with the aerial I made up a cable from the socket to the TV, one end F type, the other Co-ax.
I might investigate the two sockets that don't work, but for now it's all good.
Splitter in the loft - two cables connected, 6 sockets working, 2 sockets connected to TVs, 100s of channels on both tvs.
Thanks for the chat, it spured me to take some action!
Cheers,
Rob