Attic aerial in Athlone

an_other

Hi

I'm looking for an attic ariel to install in my attic that will pick up RTE 1,2 and TV3 and Tg4.

Any suggestions?

What direction do I point it?

Do I need amplifiers or any other equipment?

coylemj

Your local transmitter is Cairn Hill in Co. Longford, you need a Group B UHF aerial with horizontal polarity pointing at 21 degrees true, that's NNE.

Whether it will work from the attic or the rooftop depends on the altitude of your attic and whether the aerial will be pointing towards a line of seperating walls in a terrace of houses or straight at the transmitter through just your roof tiles.

an_other

How many elements on the ariel do I need?
What cost are these ariels where do i buy them?

Sorry for the dumb questions, I have been putting off doing this job for ages.

TheDriver

depends where you buy them i.e. maplin might charge you a fortune. FInd out where trade goes up there, I usually get aerials for 10-20 euro depending on brand. Amp should be 10-15, powersupply 10 etc.

an_other

So I need more than an ariel?
What kind of amp and power supply do i need.
do i need power in my attic?

TheDriver

again it depends on how good your reception is, but generally unless you are very close to the transmitter, you will need some form of amp. Power can be sent up your coax from your living room, its easy enough. If you search on the net, theres a few nice diagrams showing the setup but generally its aerial-amp-coax down your house-power supply-tv/vcr

an_other

How many elements would i need on the arriel
I am in athlone about 30 mile from the cairn hill transmitter.

Cheers The Driver

lucernarian

Amps are overrated for the price. It makes a small but crucial difference on rather snowy reception or on cable lengths >25 feet. €30 better spent on a better aerial.

Element numbers are also a pain. They're not really comparable, as the aerial makers with the "X" elements seem to count bits of the element as discrete elements themselves.

The gain value is what matters most in an aerial. Nearly every aerial will have values between 10dBi and 17dBi. The more, the merrier but aerials more than 14 dBi can be fairly pricey. If you're looking to get a plain basic aerial with no fancy X elements, then go for the 18 element as it'll work slightly better.

The roof will make the biggest difference. I've experiemented with Cairn Hill and cheap Group A, Group C/D contract aerials and a wideband grid aerial. All of them performed admirably outside, even at ground level. In the attic, I could never get it better than a bit snowy with some interference lines on 2 or 3 of the channels. To be fair, I live about 70 miles from Cairn Hill.

For an attic aerial I'd get the biggest one I would want to pay for.

an_other

cheers guys

mayto

A friend in Athlone got a high gain aerial in B&Q and working fine in the attic. I think its this one here http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_secondid=9686694&fh_view_size=10&fh_start_index=10&fh_location=%2f%2fcatalog01%2fen_GB&fh_search=aerial&fh_eds=%C3%9F&fh_refview=search&ts=1249597881329&isSearch=true#ancBVReviewsContainer .The picture quality is fine for him.

lucernarian

Thanks for that info.

Athlone is fairly flat so that report should be relevant throughout the town.

The gold plated gimmickery can be skipped. You can get a cheaper X-element aerial off someone local, and the quality isn't an issue anyway when it's in the shelter of a roof.

Here's an estimate, a group B 18 element (plain elements) would have about as much gain as the B&Q type above. And it would usually be a good bit cheaper. The advice only makes a difference if you have a choice in where you can get it! So call into a local place and see what they have.

HTH

an_other

Great help guys thanks.
Mayto did your friend need amps or anything like that?

an_other

Ok here's the update.
I went out and bought an 18 plain element type B ariel installed it in my attic pointed it at 21 degree NE (compas wasn't the best).
I now have picture but it's pretty crappy and TV3 is unwatchable.
Do I need an amp or a better ariel?

lucernarian

Yikes. Are the elements of the aerial lying parallel to the ground when it's being used?? What's reception like if you point the aerial out a North-facing window? How long is the cable?

Also, did you try it in different parts of the attic?? It made a huge difference for me when I was trying that in my own attic.

mayto

no amp used an_other. he is out near hodson bay so may have better signal from cairns hill. Raising the height of the aerial made a big difference, we raised the aerial up with a piece of wood.

an_other

It's as high as I can get it almost touching the roof in the attic.

It's pointing directly at the inside of the roof so it has no walls or anything in the way. Could it be too close to the roof?

The cable is probably 6 or 7 metres from ariel to tv
maybe i but on a plug arse ways or something.

I was going to buy an amp but maybe i should buy a better ariel the one I bought cost less than a tenner

mayto

Did you try the aerial outside at all or are you confined to the attic. The aerial my friend used is big enough, but really should be outdoors so he can show neighbours his gold aerial . Does anyone else in Athlone sell aerials as B&Q are probably well overpriced for aerials.

an_other

Im stuck with the attic unless I get someone in to install it

lucernarian

It's possibly too close. You need to vary the location of the aerial in the attic, not tie it to the first high point you can find. If you find a good spot while holding it, you can use some solid wire or even string to suspend it from the beams in that position.

Varying the location of the aerial made a much bigger difference to me than the type of aerial, whether I stuck a booster on it or what cable I used.

*Generally speaking* having it near metal objects or especially, pointing through metal pipes etc will make it worse.

Finally, can you get a wee portable TV into the attic to help with aligning the aerial?? It's the only sure-fire way to get the best position, unless you get someone to shout up to you when the reception is good.

an_other

Got a TV into the attic and got the picture spot on.
The picture on the main TV downstairs is brutal though. I have checked the plugs at both ends and no difference.
The run from the attic to the main TV is only about 4 metres of cable.
Amp or better ariel?

tellyman

It sounds like a bad connection to me.
Also make sure your TV is tuned to UHF channels 40 42 46 and 50. You may be picking up RTE on VHF, hence the bad signal.

an_other

when you say bad connection, do you mean one of the plugs or the plate on the wall?

tellyman

an_other wrote: »

when you say bad connection, do you mean one of the plugs or the plate on the wall?

Check all connections. I've come accross many wall plates where electricians have left the braid touching the inner core or even looping the cable to another room. If the socket is hidden you can dismantle the wall plate and use F connectors and a "bullet" connector. If possible use F connectors in the attic also if you have to join the cable.

an_other

Right guys here is my full status.

Location: Athlone
Ariel: Type B

The Ariel is located at the highest point in my attic pointing at 21 degrees North East (Cairn Hill)

The Coax from the wall plate in my Living room is connected directly to the Ariel (one single cable from wall plate to Ariel)
(I removed the wall plate and checked the connection)

Sound is perfect, picture is very snowy and rte 2 has loads of diagonal lines across the screen.
(I purchased moulded cables to connect from wall plate to TV)

I purchased a signal boaster (€25 from B&Q)
I plug in booster at the wall plate and plug from booster to TV
Makes feck all difference to the picture, I have turned the booster from it's highest to lowest setting no visible difference.

What do I do now?
would a mast head amp in my attic help me?

John mac

The Coax from the wall plate in my Living room is connected directly to the Ariel

have you tried direct connection from the tv to the aerial ?
leave out the wall plate and see what happens,

an_other

same story john

lucernarian

The signal is perfect when the aerial is connected to a portable TV in the attic with a short cable, right??

If it's poor when you connect to the TV downstairs with the other cable and the wall socket, then surely the problem must lie between the two?

Boosters only make a small difference in picture quality when the signal is not very strong and is weakened further by the cable length. Not to remedy a cable fault.

Also, the portable TV may have been tuned properly but the main TV downstairs may be tuned into the wrong transmitter. Do as tellyman said, but the correct frequencies are

RTÉ1 Ch 40
RTÉ2 Ch 43
TV3 Ch 46
TG4 Ch 50

an_other

what are those frequencys in mhz?

lucernarian

http://www.digitalspy.co.uk/terrestrial/tuning/

an_other

I was already tuned into the right channels so

lucernarian

To_be_confirmed wrote: »

The signal is perfect when the aerial is connected to a portable TV in the attic with a short cable, right??

If it's poor when you connect to the TV downstairs with the other cable and the wall socket, then surely the problem must lie between the two?

Boosters only make a small difference in picture quality when the signal is not very strong and is weakened further by the cable length. Not to remedy a cable fault.

an_other, could you read the above and give me an answer on that? I hope it narrows down the problem for you at least!

Booms

Have you checked that the cable you've connected to in the attic is the same one that goes to the TV? Obvious i know, but a lot of pre-wired houses have more than one cable going up to the attic from other rooms as well.
You could also try running a length of coax from the aerial in the attic out the hatch and directly to the tv just to know that it'll work.

an_other

I was back playing with this at the weekend. (I wanted a better picture on RTE 2 for the match)

I brought a portable TV into the attic and connected it to the ariel.
When I had my hand on the aerial moving it the picture was perfect.
When I take my hand off the aerial the picture went snowy again.

So I can get perfect picture in my attic when I touch the aerial but its crap when I take my hand away.

What does this mean?

lucernarian

Is aerial wired up right?? As in, the inner core is going to one terminal and the shield is definitely not touching the inner core, and is also screwed to the other terminal?? (or touching the metal clamp that holds the cable in place if you have the other sort of aerial connection)

If no improvements can be gained from that, I'd suggest moving the positioning of the aerial around, creatively even. Don't worry about exact positioning. All that matters is if it works!

Also, make sure you followed through with the other suggestions mentioned previously.

Good luck!

an_other

Picture is now perfect I just hope it stays that way.
I think the braid wasn't secure enough in the terminal. I re did it and picture was bang on.
Thanks for all the help guys.