Aeriel question

Redriddick

Hi Guys,
As per my previous post i got a new telly.I have an existing aeriel outside on top of an old eircom pole.I put it up there when i buitl the house 6 years ago.I have not used it for awhile but since i got the new telly i tried hooking it up to it.It used to be able to get all the analog stations irish and english.I did a scan for the dtt channels and it got them but the picture was distorted.I am on the outskirts of roscommon town and my mast should be cairn hill but mine and other houses are pointing towards southwest.Just wondering should i change direction of aeriel.There is a masthead amplifier out at the pole and something plugged in the attic.

Tom Slick

If the aerial got Irish & English stations,pointing SW,maybe it's on some kind of local "deflector" (I know nothing about Roscommon):) Masthead amp would be for (I assume) long cable from pole.

lucernarian

Redriddick wrote: »

Hi Guys,
As per my previous post i got a new telly.I have an existing aeriel outside on top of an old eircom pole.I put it up there when i buitl the house 6 years ago.I have not used it for awhile but since i got the new telly i tried hooking it up to it.It used to be able to get all the analog stations irish and english.I did a scan for the dtt channels and it got them but the picture was distorted.I am on the outskirts of roscommon town and my mast should be cairn hill but mine and other houses are pointing towards southwest.Just wondering should i change direction of aeriel.There is a masthead amplifier out at the pole and something plugged in the attic.

When you say "dtt channels" do you mean the irish test service or Freeview from Enniskillen?

Redriddick

To_be_confirmed wrote: »

When you say "dtt channels" do you mean the irish test service or Freeview from Enniskillen?

Thanks for the reply.Its the irish test service that i was getting.Just got a new tv with mpeg4 tuner and wanted to try it out:)

lucernarian

Redriddick wrote: »

Thanks for the reply.Its the irish test service that i was getting.Just got a new tv with mpeg4 tuner and wanted to try it out:)

Ok then. Can you find out for me on what UHF channel/s you're finding any irish DTT channels?

Do you have one aerial pointing SW or 2 aerials pointing southwest with a smaller one horizontally aligned and the other vertically aligned?

Redriddick

To_be_confirmed wrote: »

Ok then. Can you find out for me on what UHF channel/s you're finding any irish DTT channels?

Do you have one aerial pointing SW or 2 aerials pointing southwest with a smaller one horizontally aligned and the other vertically aligned?

Channel 47 i thinkand i just have the one aeriel about a meter and a half long.

Tom Slick

Redriddick wrote: »

Hi Guys,
As per my previous post i got a new telly.I have an existing aeriel outside on top of an old eircom pole.I put it up there when i buitl the house 6 years ago.I have not used it for awhile but since i got the new telly i tried hooking it up to it.It used to be able to get all the analog stations irish and english.I did a scan for the dtt channels and it got them but the picture was distorted.I am on the outskirts of roscommon town and my mast should be cairn hill but mine and other houses are pointing towards southwest.Just wondering should i change direction of aeriel.There is a masthead amplifier out at the pole and something plugged in the attic.

So,when you put up the aerial,you just copied the neighbours?How do you know what it's pointed at?(did you ask the neighbours)

lucernarian

Redriddick wrote: »

Channel 47 i thinkand i just have the one aeriel about a meter and a half long.

You think?:) Is that what the TV reports? Did you try doing a full scan to see if they show up anywhere else? And how are you getting both Republic and Northern channels on the one aerial in Roscommon?

Redriddick

Tom Slick wrote: »

So,when you put up the aerial,you just copied the neighbours?How do you know what it's pointed at?(did you ask the neighbours)

i reckon there must be a deflector alright as there is a hill with a mast and red light on it about 2 miles away.

Redriddick

To_be_confirmed wrote: »

You think?:) Is that what the TV reports? Did you try doing a full scan to see if they show up anywhere else? And how are you getting both Republic and Northern channels on the one aerial in Roscommon?

The tv reports its on 47.dont know how im getting utv but it was there not great but there.

lucernarian

Redriddick wrote: »

The tv reports its on 47.dont know how im getting utv but it was there not great but there.

Hmmm. Are your analogue irish channels in good quality? Do you get a good TV3 signal?

It would be very handy indeed if you could tell us what UHF/VHF channels your RTE and TV3 stations are coming in on.

Sorry for all the questions, but they all have a point and will help figure out what's going on asap.

Redriddick

To_be_confirmed wrote: »

Hmmm. Are your analogue irish channels in good quality? Do you get a good TV3 signal?

It would be very handy indeed if you could tell us what UHF/VHF channels your RTE and TV3 stations are coming in on.

Sorry for all the questions, but they all have a point and will help figure out what's going on asap.

Rte 1 is good.Tv3 is sh**e and rte2 not much better will try and get what channels there on.No bother with the questions it all helps and thanks

Redriddick

Rte1 is on 40 and rte2 is on 43

lucernarian

Yeah, if you find out what they're tuned in on, it would help lots.

2 other things: Firstly, watch out for Ch 40, 43, 46 or 50 as they're from Cairn Hill in Longford which is where you're getting that DTT signal.

Secondly, Cairn Hill should be roaring in to anywhere in Roscommon Town based on the coverage map I have. Once an outside aerial is being used.

Is the aerial aligned as follows?:

. /
[Southwestwards] __/________________ [Northeastwards]
\
\

In the diagram, the arrow shape makes it look like it's pointing SW but it's actually picking up the signal from the NE.

Redriddick

To_be_confirmed wrote: »

Yeah, if you find out what they're tuned in on, it would help lots.

2 other things: Firstly, watch out for Ch 40, 43, 46 or 50 as they're from Cairn Hill in Longford which is where you're getting that DTT signal.

Secondly, Cairn Hill should be roaring in to anywhere in Roscommon Town based on the coverage map I have. Once an outside aerial is being used.

Is the aerial aligned as follows?:

. /
[Southwestwards] __/________________ [Northeastwards]
\
\

In the diagram, the arrow shape makes it look like it's pointing SW but it's actually picking up the signal from the NE.

It is pointing exactly like that so my bad
did a scan again there now and the dtt channels have gone maybe this aerial needs a bit of tweaking after the last few years!!!

lucernarian

Honestly unless the aerial has thick trees or a farm shed or something large in the way to the northeast, you've got a problem with the aerial itself or the amp, cable etc between the aerial and your telly. I assume there's no hill in the way to the NE near your house either.

I can pick up Ch 47 DTT from Cairn Hill, in Co. Louth on an indoor aerial in some parts of the family home! Over 60 miles away. Any functioning aerial if it were put on top of a telephone pole, pointed in almost any direction, would pick up Cairn Hill in Roscommon Town.

Last question from me this evening: Did the analogue signal for RTE2/TV3 used to be very good and slowly deteriorated or was it a sudden loss of reception? Or was RTE2 and TV3 always a bit weak from when you put the aerial up?

Redriddick

To_be_confirmed wrote: »

Honestly unless the aerial has thick trees or a farm shed or something large in the way to the northeast, you've got a problem with the aerial itself or the amp, cable etc between the aerial and your telly. I assume there's no hill in the way to the NE near your house either.

I can pick up Ch 47 DTT from Cairn Hill, in Co. Louth on an indoor aerial in some parts of the family home! Over 60 miles away. Any functioning aerial if it were put on top of a telephone pole, pointed in almost any direction, would pick up Cairn Hill in Roscommon Town.

Last question from me this evening: Did the analogue signal for RTE2/TV3 used to be very good and slowly deteriorated or was it a sudden loss of reception? Or was RTE2 and TV3 always a bit weak from when you put the aerial up?

Rte2 and tv3 were always a bit weak i remember.Will take down the aerial and give it a good look.Maybe the connection from the cable to the aerial is corroded.Thanks a mil for all the help and will let ye know later today!

The v shaped head of the aerial is pointing southwest ?

Thats the back of the aerial man.
The v is a shield thats supposed to stop channles coming in from transmitters on the same frequency.

Your aerial is pointed away from cairn hill and towards brougher by the looks of things.

What channel is utv analogue on?

lucernarian

BB, Cairn Hill is northeast of Roscommon town. The aerial is pointing in that direction according to Redriddick. Brougher Mtn. would be north of Roscommon so the aerial would still manage to pick up some of that signal.

Redriddick, how far are you outside the town? If you're more than about 2 miles to the north of the town centre, there's a fairly big hill which would significantly weaken the signal from Cairn Hill. Maghera from Co. Galway would be your best bet.

Anyway, do post the UHF channel numbers you're receiving your stations on.

mea culpa
When I think of Roscommon,I think of North Roscommon,thats what the N4 does to you.
Carry on

(on a point of information Cairn hill can be received now in south wicklow including arklow in colourfull watchable reception with a group B pointed Northwest! despite a lot of mountains,it used be an absolute nuisance to presely analogue with wavy co channel lines-I can still see it here despite also receiving presely dtt on the same channel though it's a black and white very faded signal but it has sound)

lucernarian

Yeah, the FM sound would hold up better to same-channel DTT than the AM video would.

Redriddick

To_be_confirmed wrote: »

BB, Cairn Hill is northeast of Roscommon town. The aerial is pointing in that direction according to Redriddick. Brougher Mtn. would be north of Roscommon so the aerial would still manage to pick up some of that signal.

Redriddick, how far are you outside the town? If you're more than about 2 miles to the north of the town centre, there's a fairly big hill which would significantly weaken the signal from Cairn Hill. Maghera from Co. Galway would be your best bet.

Anyway, do post the UHF channel numbers you're receiving your stations on.

Im just off the athlone road about 3km outside the town.Anyhoo have the aerial down at the mo having a look.The place where the cable attaches looks like water has got to it so will give it a good cleaning out and put it back up maybe a bit higher.When i have that done ill do a scan again to see if there is any improvement!

watty

you need to replace the cable completely if water got in.

The attenuation will be savage.

lucernarian

How long is the cable and what sort of route does it take? Does it go underground?

Where you are, you have pretty much Line of Sight to the most powerful transmitter in the country. An indoor aerial should work very well through a north-facing window let alone an outdoor aerial. Something is very wrong between the aerial and TV as there simply should not be any signal issues where you are. As watty says, if there's even a slight chance that water got in, the cable must be replaced. If it's been rubbing off branches, tiles or walls then it can wear a hole through the cable too and cause problems that way also.

I forgot to ask, why do you have it on a telephone pole anyway? You could stick it somewhere northeast facing, 2 metres off the ground and it would probably work as well in your location and without all the long cable.

or even in the attic...

lucernarian

Some attics would have foil lined insulation, especially if built in the last decade like the OP's is. I live in a house which has foil-lined insulation in the attic and a grid aerial has difficulty picking up a signal from Three Rock despite being in Dublin city centre. Also, it's pretty quick to check what reception is like with propping one up outside rather than having to get the ladder and rummage around in the loft.

Redriddick

To_be_confirmed wrote: »

Some attics would have foil lined insulation, especially if built in the last decade like the OP's is. I live in a house which has foil-lined insulation in the attic and a grid aerial has difficulty picking up a signal from Three Rock despite being in Dublin city centre. Also, it's pretty quick to check what reception is like with propping one up outside rather than having to get the ladder and rummage around in the loft.

Alright guys i put the aerial back up at around 4 this evening and bang there they were all the dtt channels and the analogue.The analogue were not great but the dtt were perfect.Went out for a few hours and turned the tv back on there about ten minutes ago and the dtt channels were completly gone again would it be the rain or what could have caused it.

lucernarian

You've got to replace that cable if water has gone into it, which it has, and check to see if the amp's power supply is wired properly in the attic. Is the amp supplying the one TV? Also, check out this page: http://www.glodark.co.uk/cable.htm . There shouldn't be any "Type D" between your TV and the attic.

Type C is also not very durable and can easily corrode if in damp environments because the foil screen and the copper wires can react with each other. Type D is cheap muck found in various DIY or electrical wholesalers. Type C is usually called "satellite RG6" cable in shops but isn't as good as the CT100/WF100 branded cables, but is a big improvement on cheap "low loss" coaxial cable.

Once again, masthead amps (the one attached near the aerial) are very prone to water ingress. Make sure there's no water getting into that at all costs as a broken or shorted amp is worse than no amp at all.

And to answer your question, what's actually causing all this is a problem with your aerial, amp or cable. Something needs replacing one way or another if water's getting inside the setup. Rain shouldn't affect anyone's reception if it's working as planned.

Redriddick

To_be_confirmed wrote: »

You've got to replace that cable if water has gone into it, which it has, and check to see if the amp's power supply is wired properly in the attic. Is the amp supplying the one TV? Also, check out this page: http://www.glodark.co.uk/cable.htm . There shouldn't be any "Type D" between your TV and the attic.

Type C is also not very durable and can easily corrode if in damp environments because the foil screen and the copper wires can react with each other. Type D is cheap muck found in various DIY or electrical wholesalers. Type C is usually called "satellite RG6" cable in shops but isn't as good as the CT100/WF100 branded cables, but is a big improvement on cheap "low loss" coaxial cable.

Once again, masthead amps (the one attached near the aerial) are very prone to water ingress. Make sure there's no water getting into that at all costs as a broken or shorted amp is worse than no amp at all.

And to answer your question, what's actually causing all this is a problem with your aerial, amp or cable. Something needs replacing one way or another if water's getting inside the setup. Rain shouldn't affect anyone's reception if it's working as planned.

To Be comfirmed,
Thanks so much for your help.I cant get up for the aerial today cause of the wind but i think your right.Im going to get new cable ct100 and a new amp to see if that helps.I think you defo right in what your saying that water has caused the problem.Just had a look in the amp ther and it looks like a new one is in order!

lucernarian

Getting a new amp will only work if the old one had water leaking into it. It's important that the cable inside is in good nick too, so if it's feeding more than one telly make sure it's split properly with an appropriate splitter box (e.g. http://cpcireland.farnell.com/labgear/fju402/splitter-2-way-uhf-5-1000mhz/dp/AP02104 or outdoor: http://cpcireland.farnell.com/proception/promhs12p/mast-head-splitter-2-way-screened/dp/AP01855)

I've seen cables that were held together with nothing better than a few twists and some sellotape. The location wasn't great for signal to begin with so at best it managed the odd splash of teletext.

It's all common sense really, if a cable or an aerial or an amp looks bashed or damaged then the signal will likely suffer too. Replace as necessary! And aerials/amps can be made watertight with some silicone grease and self-amalgamating tape or possibly even bog standard silicone sealant.