Group A antenna versus group k

Andy454

I bought a 100 element group A antenna and 34db gain masthead amp in the hope of getting Brougher mountain, but found nothing on testing (probably due to trees and buildings nearby.

However I did find a very weak signal from Divis, I am just wondering now whether to go back and get a group k antenna and masthead amp, if that would improve reception by any significant proportion.

looking at the channel spread Divis and Brougher mountain don't differ that much - Ch 21 -34 Divis and -ch22 - 34 on Brogher.

I was testing in west leixlip - but again very low down only about 3m from ground, would it be worth while going higher up or would I be wasting my time and just look for a group k

PauloMN

Group A is a narrower band than group K, so I expect a group K aerial won't perform as well as a group A on the main analogue channels (which I assume are what you are currently trying to receive).

http://www.bbc.co.uk/reception/transmitters/tv/tv_divis.shtml

A decent high gain group A aerial is what you want for Divis. Make sure it's pointed in exactly the right direction and that it's horizontally polarised. It'll need to be pretty high off the top of the roof given where you are, and even at that still might not produce reliable results.

Free to air satellite is probably your best option.

If a 15ft pole at the roof will get you above any tree's towards Divis,then go for that.
Stick with the group A gear.
I'd retry brougher at that height also-hell if you are north of the wicklow mtns and even at that distance inland,I'd try Blaenplwyf for the crack
Making sure the aerial is horizontally polarized is obvious.

Tree's all but kill distant signals- ESPECIALLY at this time of the year when they are in full leaf.

Digifriendly

Deleted User wrote: »

Tree's all but kill distant signals- ESPECIALLY at this time of the year when they are in full leaf.

Very true. I live about 15 miles as crow flies from Divis, I have a 27 element Televes with added set back booster and I still get breakup on Ch.48 multiplex during the summer due to trees directly between aerial and transmitter.

lucernarian

Andy454 wrote: »

I bought a 100 element group A antenna and 34db gain masthead amp in the hope of getting Brougher mountain, but found nothing on testing (probably due to trees and buildings nearby.

However I did find a very weak signal from Divis, I am just wondering now whether to go back and get a group k antenna and masthead amp, if that would improve reception by any significant proportion.

looking at the channel spread Divis and Brougher mountain don't differ that much - Ch 21 -34 Divis and -ch22 - 34 on Brogher.

I was testing in west leixlip - but again very low down only about 3m from ground, would it be worth while going higher up or would I be wasting my time and just look for a group k

Which out of the 4 analogue channels did you manage to pick up? From what I remember of Leixlip and the area, the only NI aerials I saw were quad aerial arrays pointing to Divis on top of a mast. I wouldn't bother with a Group K, the one weak multiplex that may be picked up with it will be in Group A in less than 3 years.

Brougher Mountain won't work in Leixlip in a month of Sundays (whatever about a month of good weather:D). I have much better LOS to Brougher Mountain where I am, and Divis is still much stronger despite a small hill being in the way. The higher ERP really does make a big difference in Divis' favour. I cannot try for Blaenplywf where I am because of another, much closer, hill shielding anything east of Three Rock (and weakening three rock too).

The Dublin Mountains would be a formidable opponent to getting any signal in Leixlip from Blaenplwyf though.

Also, height makes a massive difference. I get a barely registerable signal at ground level for Divis, and mediocre at roof height, but 2 metres or more higher and I can manage okay reception with working teletext and ceefax.

watty

45ft above ground is the magic "1st height" for an aerial. After that you have to double the mast height pretty much if your signal is there but not good enough.

Isn't leixlip just due west of the phoenix park iirc? that would be a good few miles north of the dublin mountains and north of the city centre.
I'd actually try llandonna,arfon[if I had a wideband or group b ,the latter preferably in their case] and Blaenplwyf for the crack but Watty is right..to be in with a half decent chance,you'd need 45ft probably.
I'd agree it's a tall order but since he has a group A,I'd be atrying for the crack.

Brougher has been reported on this forum loud and clear in dtt in Mulingar.I advised andy of that in the mt leinster thread when he asked and was why I suggested he look for it in leixlip.

Gtg60 incidently has reported fair to good Divis reception higher up on his road in Wicklow town which goes to show what gaps in hills and the veracity of signal can do.
There aren't a whole lot of hills between Leixlip and Mullingar or the NI border for that matter which is whats crucial given the signal gets south of the border anyway.
What would matter,to repeat would be if Andy's location is in a dip or if there are plenty of trees higher than the aerial or buildings etc.

An uncle of mine is picking up UK terrestrials near Celbridge on a 110ft mast. Not sure if you'd need something that high though... probably not.

Digifriendly

Karsini wrote: »

An uncle of mine is picking up UK terrestrials near Celbridge on a 110ft mast. Not sure if you'd need something that high though... probably not.

That's some height! Is there not a problem with wind and how is it kept secure?

FREETV

watty wrote: »

45ft above ground is the magic "1st height" for an aerial. After that you have to double the mast height pretty much if your signal is there but not good enough.

Watty, how long would it take to get planning permission before a very tall mast could be erected and how much would the planning permission cost roughly please?

FREETV

Karsini wrote: »

An uncle of mine is picking up UK terrestrials near Celbridge on a 110ft mast. Not sure if you'd need something that high though... probably not.

Karsini, how long did it take for him to get the planning permission for the mast to be erected? What were the planning permission fees roughly and did he get the mast professionaly installed? If so what were the costs please if you can find out? Thanks.

watty

Ask your local council. Kerry is expensive. It varies per council.

It's rare to get more than 45ft approved. Considering you can have a big pole on chimney without planning permission (forget if it's 3m or more), it's only worth having a 45ft mast if you are in a bungalow/cottage.

The mast was already there when they moved in to the house. It's supported with guy wires so there shouldn't be any major stability issues.