Aerial direction

Dr. Nick

With all the expert opinions on here, it's a little difficult to discern the wheat from the chaff, so I still don't know which direction my aerial should be.

I live in mid/south Meath and it currently seems to be pointed to the Longford transmitter, but I've had some recent hiccups (lip-sync, pixilation, total 1-second drops - may be worse in rain). Local tv guy did the installation, aerial is outside on sattelite pole.

Should it be pointed to Drogheda? I'm probably 25 miles away as the crow flies.

STB

Dr. Nick wrote: »

With all the expert opinions on here, it's a little difficult to discern the wheat from the chaff, so I still don't know which direction my aerial should be.

I live in mid/south Meath and it currently seems to be pointed to the Longford transmitter, but I've had some recent hiccups (lip-sync, pixilation, total 1-second drops - may be worse in rain). Local tv guy did the installation, aerial is outside on sattelite pole.

Should it be pointed to Drogheda? I'm probably 25 miles away as the crow flies.

What hardware are you using ? Lip sync ? Its not a Humax box is it ?

What is the frequency that you are tuned to ?

Is their a signal strength meter on whatever you are using ?

Aerial and Amplification set up ?

jamescc

Dr. Nick wrote: »

With all the expert opinions on here, it's a little difficult to discern the wheat from the chaff, so I still don't know which direction my aerial should be.

I live in mid/south Meath and it currently seems to be pointed to the Longford transmitter, but I've had some recent hiccups (lip-sync, pixilation, total 1-second drops - may be worse in rain). Local tv guy did the installation, aerial is outside on sattelite pole.

Should it be pointed to Drogheda? I'm probably 25 miles away as the crow flies.

am in the same boat but try this:

http://www.mpeg4ireland.com/map

just pin point on the map may help might need a compus

lucernarian

Two things: firstly don't point it to Drogheda as nothing is transmitting there

Secondly, mid/south Meath isn't specific enough. Can I just get it over with and call it Trim say?!:pac:

The Dublin transmitters would be a better bet if you wanted to try somewhere else but the odd breakup is always going to happen on a trial service that's (in the case of Longford) still running over equipment designed for analogue broadcasts.

How big is the aerial? Is it a standard 10-element "contract" aerial (use google images to decide)? Does the aerial have an unobstructed view to the northwest or is the aerial very low down/pointing through a roof/nearby large tree etc?

STB

And it likely that nothing will broadcast from Drogheda.

Eitherway its 738MHZ or channel 54.

lucernarian

STB wrote: »

And it likely that nothing will broadcast from Drogheda.

Eitherway its 738MHZ or channel 54.

The minister did say in the Dáil only 6 months ago that equipment for Drogheda was being prepared for 31st Oct, among other places. I would say that if a new relay is being built in Arklow, it's quite plausible that one would be provided for Drogheda too. I just hope it's directional...

In any case, a signal from Drogheda would never reach beyond Slane into Co. Meath really. Certainly not past the hill of Tara anyway.

PauloMN

I'm in Trim and I'm using Clermont Carn near Dundalk for my DTT on an attic mounted aerial. Reasonable analogue signal and near perfect digital (breakup from time to time), so am moving it outside.

Most houses in Trim are using Clermont Carn if you look at the small UHF vertical aerials on the houses. Pointed pretty much the same direction as the large Divis aerials.

Make sure the aerial is high enough to clear nearby trees.

jamescc

PauloMN wrote: »

I'm in Trim and I'm using Clermont Carn near Dundalk for my DTT on an attic mounted aerial. Reasonable analogue signal and near perfect digital (breakup from time to time), so am moving it outside.

Most houses in Trim are using Clermont Carn if you look at the small UHF vertical aerials on the houses. Pointed pretty much the same direction as the large Divis aerials.

Make sure the aerial is high enough to clear nearby trees.

i went and got a gizmo from argos to test the signal i got two bars out of 4
at least you have houses around that have aerials up to check of

i will have to higher it up

Dr. Nick

To_be_confirmed wrote: »

Can I just get it over with and call it Trim say?!:pac:


The Dublin transmitters would be a better bet if you wanted to try somewhere else but the odd breakup is always going to happen on a trial service that's (in the case of Longford) still running over equipment designed for analogue broadcasts.

How big is the aerial? Is it a standard 10-element "contract" aerial (use google images to decide)? Does the aerial have an unobstructed view to the northwest or is the aerial very low down/pointing through a roof/nearby large tree etc?

Not far from Trim, 6 miles east/south-east. Aerial is on a gable facing n-east on a sky satelite dish, so Dublin prob not an option, even though we're closer than Longford OR Drogheda.

Aerial is std 10 element, poss some trees but not much, top of gable on a dormer. Think maybe a slight adjustment might do the trick but is it just lucky dip or is there a proper measuring tool?

Dr. Nick

PauloMN wrote: »

I'm in Trim and I'm using Clermont Carn near Dundalk for my DTT on an attic mounted aerial. Reasonable analogue signal and near perfect digital (breakup from time to time), so am moving it outside.

Most houses in Trim are using Clermont Carn if you look at the small UHF vertical aerials on the houses. Pointed pretty much the same direction as the large Divis aerials.

Make sure the aerial is high enough to clear nearby trees.

Cheers.

jamescc

Dr. Nick wrote: »

Not far from Trim, 6 miles east/south-east. Aerial is on a gable facing n-east on a sky satelite dish, so Dublin prob not an option, even though we're closer than Longford OR Drogheda.

Aerial is std 10 element, poss some trees but not much, top of gable on a dormer. Think maybe a slight adjustment might do the trick but is it just lucky dip or is there a proper measuring tool?

i got a digital tv signal meter to the test where i am getting the best signal one other thing that has been brought to light lighting how do you ground an antenna?

lucernarian

Dr. Nick wrote: »

Not far from Trim, 6 miles east/south-east. Aerial is on a gable facing n-east on a sky satelite dish, so Dublin prob not an option, even though we're closer than Longford OR Drogheda.

Aerial is std 10 element, poss some trees but not much, top of gable on a dormer. Think maybe a slight adjustment might do the trick but is it just lucky dip or is there a proper measuring tool?

The sky dish would be pointing in roughly the same direction as the Three Rock transmitter in Dublin so if the house isn't blocking the sky dish, it shouldn't block the aerial signal from there. The Longford transmitter is NW of where you are so it's pointing in the opposite direction to the Sky dish, possibly through the gable wall too. There is no transmitter in Drogheda currently. Clermont Carn is north of Dundalk. I'm not sure I explained that very well but anyway.

I had a look at coverage maps based on maximum power transmissions when they turn off Analogue. Longford really isn't used in that entire area towards Pelletstown. It's all Clermont Carn if closer to Trim or Three Rock Mountain if closer to Dunshaughlin/Dublin. A ten-element really wouldn't give a reliable signal from Longford unless it was mounted a few feet clear of the roof but that's only an estimate really. Still, I'd strongly recommend changing the direction of the aerial, or changing the aerial itself to a more appropriate one. Clermont Carn I think is much weaker currently than it will be in 2 years, but the Dublin (three rock) one is already working at a high strength. I think you'd obtain far better results with Three Rock Mountain, on Ch. 54 for digital.

watty

jamescc wrote: »

i got a digital tv signal meter to the test where i am getting the best signal one other thing that has been brought to light lighting how do you ground an antenna?

Really. What model / make? If it doesn't show BER and which frequency it is, and is only a needle or bargraph, it's just an analogue RF level meter.


Lightning?

If that hits within 10m of your aerial, or the ESB wires in the ground on at pole it doesn't matter what earthing you have.

Probably everything plugged in will be toast.

If there is a severe Thunderstorm, then unplug ALL aerials and all mains plugs, and have mains plugs about 60cm / 2' from power sockets and Aerial cables similar or greater distance away from any electrical or electronics.

Professional aerial system and masts use a separate short vertical rod above everything with its own earth to ground spike. It doesn't protect against a direct strike, but discharges high levels of static occurring during storms.

Never earth a TV aerial or LNB. If you earth anything, earth the mounting pole only with heavy gauge earth wire connected to NOTHING else except a ground spike.

If you are unlucky to get a direct strike, you'll likely lose the chimney anyway.

A mast and concrete building under it was built incorrectly. The mast was bolted to the steel re-enforcing in the concrete building and there where no 2cm x 3mm earth straps to ground spikes. When the mast was struck, the heat of the current to ground via the re-enforcing shattered the entire equipment building and "blew off" most of the concrete.

Further scary reading
http://www.engineeringradio.us/blog/2010/06/lightning-damage/
http://www.astrosurf.com/luxorion/qsl-lightning-protection.htm
http://en.wikipedia.org/wiki/Lightning_rod

It's a complex subject and not DIY for expensive equipment.
http://www.afar.net/application-notes/lightning-protection/
http://gpr-expert.com/cell-site2.htm

Gerry Wicklow

I knew someone who unplugged his aerial during a storm. Lightening struck nearby, came through the aerial lead, scorched across the bedroom carpet and blew a hole in his central heating rad which promptly flooded the house. But at least his TV survived:)