Tv coaxial

[lurker]

Do you think we have reached the point where a house no longer needs a tv aerial and thus tv sockets and the related wiring.
My thoughts are one being needed, incase the phone line and thus the internet become disconnected.

Further, I assume running a power cable and coax together is asking for trouble?

 

[Racers]

I would run a coax i have several in my house all terminated at a amplifier in the loft.

Don't run a coax and mains cable in the same trunking keep them some distance apart 100mm should do, more on a long run.

Pete

 

[Eric The Viking]

Wot 'ee said above.

I'm just preparing to run in extra cabling, including more co-ax.

Like Pete I have a distribution amplifier in the loft, which has the ability to combine a number of signals* into one cable. That makes the other end(s) neater.

E.

*Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB ("digital radio") can all go down the same cable, with a bit of planning. Right now ours only does UHF & VHF, but has the capability to do all four.

 

[sunnybob]

I had this house built "off plan" in 2006. I altered the plans to have phone cable sockets in every room, and each side of the downstairs rooms (shows how good I am at predicting :roll: )
They have never been used due to mobile phone developments and internet TV.

If I was starting again (god forbid) I would have co axial and ethernet cables everywhere. wi fi routers can be very unreliable, but if the internet goes down.....

and believe me, you wouldnt wish greek TV on the person you hate most in the world (hammer) (hammer) (hammer)

 

[Robbo3]

Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB ("digital radio") can all go down the same cable, with a bit of planning. Right now ours only does UHF & VHF, but has the capability to do all four.

What happens at the bottom of the single cable? When you split it don't you get signal loss or is the loss acceptable as a trade off for convenience?

 

[Eric The Viking]

Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB ("digital radio") can all go down the same cable, with a bit of planning. Right now ours only does UHF & VHF, but has the capability to do all four.

What happens at the bottom of the single cable? When you split it don't you get signal loss or is the loss acceptable as a trade off for convenience?

No losses because of the multiplexing (signals sharing one cable) - each has its own frequency band and they don't really interact. You will get signal loss from distance (especially with the higher frequency ones such as satellite), and incorrect termination...

... What does cause issues (potentially lots) is splitting the cable to multiple outlets. If this isn't done properly, you get reflections from the open ("unterminated") ends of the unused cables, which interfere with the wanted signal. In the days of analogue TV, this would typically show up as "ghosting" - a second ghostly image shifted slightly to left or right of the picture. In digital systems it doesn't cause as much of a problem, unless it's severe, in which case the thing just won't work, even though it checks out with a multimeter.

The cure for this is almost always correct termination (75 Ohms in the case of CoAx), and using distribution amplifiers (DAs), and/or proper signal splitters. What you cannot do is just splice cables together when you want multiple outlets. Splitters, and even decent DAs aren't expensive though, because they are used a lot and the components inside them are cheap - splitters are just three resistors in a box with sockets on (obviously they need to be the right value resistors! though).

You used to be able to get pretty decent splitters and DAs from Toolstation - it's where mine came from. Labgear is a pretty reasonable brand.

The only slightly annoying issue nowadays is that the connectors on them are "F" connectors (ubiquitous in the USA), but the back of British TVs and usually the wallplates too are "Belling Lee". F conns are easy to use and fit to cable, Belling Lee less so (if you want them reliable!), but both are cheap - you probably can't get away with just one type. The image below is actually of a pair of converters, but of the bits you can see into, Belling Lee is on the left, "F" on the right.

In use, the solid copper core of the co-ax forms the pin you see on the right, but that has to be soldered into the fatter pin of a Belling Lee plug (if you are doing it properly!). Wall plates usually have screw terminals for cheapness - not nice and need a bit of care when you connect cables to them. Earthing is important and has to be done with care.

Yes it's an easy DIY job, but a bit of understanding is necessary for more complex setups (e.g. lots of outlets or lots of aerials being combined).

 

[Just4Fun]

I will buck the trend. I wouldn't bother with coaxial cables. A few years ago I put in a load of network cabling in my house. I also bought some coaxial cable intending to run that at the same time. I never got around to doing that and the cable is still kicking around in my workshop. I have not once thought "I wish I had installed that coax".

 

[Eric The Viking]

I will buck the trend. I wouldn't bother with coaxial cables. A few years ago I put in a load of network cabling in my house. I also bought some coaxial cable intending to run that at the same time. I never got around to doing that and the cable is still kicking around in my workshop. I have not once thought "I wish I had installed that coax".

I have a lot of analogue kit, some of which is rather unusual, and for me it's very useful.

If you only have digital stuff, there's little reason to use CoAx, I can see. But anything coming off an aerial will need it, so it depends.

The other thing I will readily concede is that stuff using CAT5 gets moved around much more than TVs and HiFi radio kit does, so it makes sense to have proper structured wiring available. I just got an upgrade done to our WiFi before lockdown, and although the bandwidth of the new access points is huge (compared to client use), cabled CAT5 systems still seem oodles faster than the handheld devices we have.

 

[Sheffield Tony]

I used to solder the centre pin of TV antenna connections, but noticed nobody else seemed to bother. Just poking it in seems to work fine - I guess even in absence of a solid comnection there's enough capacitive coupling. But I guess soldered is better.

When dealing with EMC issues, it is always amazing how easily rf signals can couple unintentionally.

 

[DBT85]

I personally would not bother with coax today. I don't use it in the home in any way so I wouldn't spend the time and a effort to run it everywhere.

Putting ethernet in is a much better use as it can carry so many things. Power for some devices, network, hdmi if needed etc.

 

[AJB Temple]

My two pence worth is that coaxial is redundant in the vast majority of cases nowadays, as are multiple phone sockets.

I think ethernet cable is very close to being redundant in most domestic settings as well.

Wireless has improved immeasurably and I would invest in good routers and boosters. 5G may well be a game changer. We have Sky Q dotted around the house, numerous laptops etc. In a previous house several years ago this would have been hopeless but wireless systems now do what they claim.

For back up we do have two incoming phone lines.

 

[Doug71]

Quick question on this topic.

I have just had a move around of furniture in living room and the Tv is no longer near the aerial and cat 5 sockets so I just run it wirelessly, fine for me as I only watch Netflix, iplayer, Youtube etc.

Problem is when my mother comes round to babysit the kids she wants to watch normal Tv and be able to flick through the channels, I don't see a way of doing this without running a coax/aerial cable to the Tv or am I missing something?

 

[Eric The Viking]

@Doug71: Yup, the simplest thing is just a run of coax. Otherwise one of those dongles that includes the Freeview channels, but I'd guess they need subscriptions.
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On WiFi speed:

I've just put in Ubiquiti 802.11ac Wave 2 Nano HD APs with a cloud controller to manage them. The firewall is pretty quick, too.

The Ubiquiti units are very good (WiFi is rock solid with two and I probably don't need the third that was planned-for), and they do have gigabit connections, but WiFi is still not anything like as fast as cabled gigabit ethernet. I suspect it's slower than the few remaining 10-baseT items on the network, although that's a subjective perception - haven't really tested it. But Netflix, for example, is fine on the telly (10-baseT), but still stuttery and awkward on the two tablets in the house. I haven't seen any maxing-out of the APs in the logs.

 

[DBT85]

WiFi will always be slower, but it's very rare people need ethernet speeds on mobile devices or even tvs and stuff. The size of files accessed just isn't big enough to need it.

All digital streaming services should be fine on WiFi. If not it could be the device itself that's the issue if its older and has lower quality WiFi gear.

That said, everything in my house is wired save for things that can't be and my laptop. My pc, server, tvs, Shield etc are all on string.

I too use a couple of Ubiquiti ceiling warts for all my wifi, though I want to add a couple more (maybe the in wall ones) as our place is a bungalow but sprawls.

 

[Robbo3]

No losses because of the multiplexing (signals sharing one cable) - each has its own frequency band and they don't really interact. You will get signal loss from distance (especially with the higher frequency ones such as satellite), and incorrect termination...
Snip

Apologies to the OP for forking the thread. I'm trying to learn & hopefully the answers will be useful to others as well.

Thank you Eric.

What I was trying to find out is if you have four devices, Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB, presumably you have to have a wall plate with one connection on the back & four on the front. Does this not require some form of diplexer?

 

[garethharvey]

Not had coax in my house for 14 years. Everything is internet based. We installed cat 6 cable around 5 years back, all feeding back to a 48 port switch. We have a fairly old house with thick walls. We ended up putting 5 wireless switches in different rooms all with the same SSID, so when you roam around the house it will pick up the strongest signal.

 

[Eric The Viking]

What I was trying to find out is if you have four devices, Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB, presumably you have to have a wall plate with one connection on the back & four on the front. Does this not require some form of diplexer?

I don't see why - the same signal can go to any/all the receivers without any issues (well, as long as they are properly designed). You will need to ensure correct termination though, which requires a passive splitter or a distribution amp. In the case of the splitter (and some designs of amp too), unused ports need a 75-ohm termination resistor across them (usually looks like a dummy plug), so the impedance calculations work out right (and there are no reflections to upset the connected receivers), but that's cheap and easy. Here's an F-connector version: https://cpc.farnell.com/vision/v17-007/ ... dp/CN19897

 

[Sideways]

I wouldn't bother with coax or ethernet as standard anymore.
Wifi and online video / audio are taking over. Landlines are a thing of the past for most of the population, and the backup for loss of wired internet is everyone's mobile phones.
Give it a few more years and optical connections right to the house will make phone sockets redundant too.
Broadcast services of all kinds will be accessed by fewer and fewer people.
Technology changes a lot in the space of a decade.

 

[flying haggis]

No losses because of the multiplexing (signals sharing one cable) - each has its own frequency band and they don't really interact. You will get signal loss from distance (especially with the higher frequency ones such as satellite), and incorrect termination...
Snip

Apologies to the OP for forking the thread. I'm trying to learn & hopefully the answers will be useful to others as well.

Thank you Eric.

What I was trying to find out is if you have four devices, Satellite, UHF TV ("Freeview"), VHF ("FM radio"), DAB, presumably you have to have a wall plate with one connection on the back & four on the front. Does this not require some form of diplexer?

short answer, yes, you have to combine all the signals via a multiplexer then you can send that signal down the coax to a diplexer that seperates them out again

 

[Eric The Viking]

You really don't/shouldn't need that (you do at the top end, because of the individual aerial impedances interfering with each other). At the bottom, the input stage of each receiver device should filter as necessary, using only what it needs and ignoring the other signals. A cheap resistive splitter at the bottom ought to be fine, assuming the signals are strong enough. I've got a 25dB-ish masthead amp for the telly, but the VHF side shouldn't need anything. Not using DAB or Sat at the moment, but I assume the LNB would produce a high enough output on its own.

I have to go to the attic in a sec, so I'll check, but I don't think there is any gain in the multiplexer (fairly certain it's passive) - the UHF amp is a separate unit upstream of it (and there is a TETRA filter beyond that actually on the pole).

[edit] Re-reading what I wrote above, I'd add this to be clear:

if you mean by 'diplexer' a two-way resistive splitter, then yes, if you want to feed two boxes from one downlead you will need one. And if satellite is involved it really needs to be decently screened too, like one of these (you can only have one satellite receiver per downlead however, apparently).

But you shouldn't need anything with filters in it at the bottom (although it should also work it will cost a bit more and may not give any benefit). I think the wall plates that have lots of different, labelled sockets on them are intended for separate cables, rather than one with all the aerial signals multiplexed down it. You can't just connect the single downlead to all the positions on the back of such a plate without causing issues.