Extra TVs off the Roof Aerial

[john west]

A house that has two Freeview Channel televisions uses an extra high roof aerial and receives from the Crystal Palace Transmitter. Due to recent strong winds it now needs a replacement aerial.

Currently the roof aerial lead goes down to the ground floor, then into a small signal amplifier with one output to the nearest TV and the other amplifier output connected to a cable that goes to the other television in the next room. Both these televisions being on the ground floor.

The signal strength is not great due to the geographical terrain between the house and the transmitter.

There is a wish to have a 'third' television. This time in an upstairs room. Would it be acceptable practice to connect another second cable to the roof aerial and run this second cable down outside and then through the wall on to the first' floor' for the third television?

Or would this arrangement present an extra load to the already fairly weak reception and so perhaps reduce the signal strength to the two already installed televisions ? They wouldn't want the extra expense of having to install two aerials. Or is there another way to simply add an extra television? Thanks.

[NY]

I imagine Bill Wright will be along soon to give a definitive answer, but I'd suggest a mast-head amplifier with multiple outputs, with a separate cable to each of the rooms.

In a very strong signal area, I got away with a mast-head splitter with one leg to the TV downstairs and the other leg driving three DVB-T tuners using two cascaded 2-way splitters. And no amplifier.

But that was with line-of-sight to Bilsdale which was about 20 miles away. Couldn't do that where I live now.

[John Rumm]

Out of interest, how long was it in use prior to being damaged?

There is also another possible issue, in that historically crystal palace always used to use channel frequencies toward the bottom of the UHF band, and so many aerials installed were "Group A" ones that covered the lower channels only.

Some of the more recent channel reshuffles have moved or added muxes well out of the original group A range. So installations with older aerials may now give poor or no reception on the muxes on the higher frequencies.

A decent quality group K aerial will cover the main muxes.

(I think COM7 has gone as they are clearing all the the 700MHz frequencies for broadcast TV so they can reallocated them to mobile broadband/5G)

The current mux channel allocations:

You normally get better results placing an amplifier at the mast head[1], and having that feed a good quality inductive splitter there, to drive multiple down leads. That tends to maintain a better signal to noise ratio.

[1] The PSU is connected to one of the downleads inside the house, and feeds power back up the co-ax to the aerial.

[Brian]

Install a decent amplifier in the loft with multiple outputs and run good quality coax to where you want TVs.

I think ours has 8 or 9 outputs. Not all are used !

Use satellite quality coax - it is cheap enough- and keep the runs as short as possible.

Replace the coax on the antenna, if not the antenna. Coax exposed to the weather gets lossy due to the jacket failing and water ingress.

[williamwright]

Fit a Group T aerial plus one of these at the bottom of the mast or near the bottom of the mast but in the loft.

You can take the extra feed from the amp and either take one feed from the amp down to the existing ground floor arrangement, or take four feeds (max) direct from the amp to each point.

The amp needs a power unit. Fit this somewhere where it won't get accidentally turned off.

Use copper foil copper braid satellite cable.

Bill

[Brian Gaff (Sofa]

Well if it were me, I'd get the best aerial you can put up as high as possible, pointing in the direction of the signal you want. I'm assuming you do not have a closer main station than that one, as the relays do not have all the channels. Take a very good cable into your loft and find a nice distribution amplifier, of which there are many and no doubt most ill get a mention in this thread, and then run your three cables to the rooms from there. I personally feel that if you do need a mast head amp, you are likely to get problems from interfering signals, or indeed mobile phones, However in much of the channels the channel is quite low in the band. Its really going to revolve a lot around finding a good installer who knows what hey are doing and won't sell you a pig in a poke where every time we get high pressure your picture pixilates. Another way around it of course is to go Freesat instead, one more box, but perhaps not as much of an issue if its installed right. Brian

[RJH]

FWIW, I've got a loft mounted aerial with a run of good quality cable to a

2-way splitter downstairs feeding 2 freeview TVs - works fine. Might be worth trying without an amplifier?

[The Natural Philosopher]

I have a loft mounted antenna feeding a lab gear 8 way distribution amp which has a two way splitter to give 9 buffered channels.

House is cabled with satellite grade coax, and has 9 belling lee sockets, all of which work.

You only need the £25 one

[Mark Carver]

Not yet, though it is due on or before  June 30th this year to cease.

Please don't quote that bloody awful site, it's full of out of date information, and speculation.

It's wrong regarding the local London mux, that's now on Ch 35, and not Ch 29.

In short, once COM 7 ceases all of CP's muxes will be situated between Ch 22 and 35.

From June nothing above Ch 48 will be used anywhere in the UK for TV broadcasting, so Group K's should be making more of an appearance (21-48)

[John Rumm]

Which site would you suggest as an alternative?

Perhaps - but not particularly relevant to this discussion.

It seems that many suppliers just herd customers toward wideband these days... probably because if it works, then it saves hassle each time they fiddle with the channel allocations.

[Mark Carver]

This site:-

Stick in your postcode etc, to the input boxes towards the bottom of the page

Yes, though a Wideband does risk causing indigestion for the tuner, if there's a mobile base station in the same direction operating between

700 and 850 MHz

[John Rumm]

Actually I did try that first, but found the poor navigation design made it hard to actually jump straight to Tx info when you are not starting with a postcode.

Which there more that likely will end up being once the top end of the TV spectrum is sold off.

[Andy Burns]

Auctions completed last April, and EE started using 700MHz from October in certain areas

[Mark Carver]

Yes, and I've seen stuff at 800ish MHz (Ch 61/62 in old money) in my area for a couple of years now. (800 MHz was cleared in 2012)

[Mark Carver]

 Everything is dumbed down to postcodes these days sadly.

There is an Excel sheet buried on Ofcom's website somewhere, but last time I found it, it wasn't up to date either.

I miss the 70s and 80s, and the BBC and IBA info services. I'm sure they miss my SAEs too !

[williamwright]

No but it's a good example of how unreliable the info on that site is.

Bill

[Andrew]

It might help if you told us your postcode.