Horizontal Dipole on roof

[odbrew]

If one were to experiment with a horizontal dipole on the roof of a 2 story home, how high above the ridge line should i put it ?

[The DB]

For best performance, as high as you can.

That being said, many people have put such an antenna inside roofs before successfully.


The DB

[odbrew]

Thanks for the reply. I built a simple inverted v out of old stripped rg59 center conductor and rg58 feedline as an experiment in my attic. Swr with that antenna were around 1.2 on both sides of the band but performance was pretty poor. I was able to receive pretty well it seemed, but my transmit was absolutely terrible. I may experiment in the attic with a horizontal this weekend as it will be a rather gloomy memorial day weekend. Any recommendation on gauge?

[MDYoungblood]

Hello odbrew,
Welcome to the forum. You could just lay it on the roof if it's asphalt shingles or any non metallic material, just for experimenting. I have a friend that built a wire beam (4 element) on his roof, it's pointed west and works pretty good.

3's

Greg

[projectcop]

MD youngblood;
I'm not trying to highjack a thread here, but where can I get more info on this wire beam you speak of?

[1206FL]

Projectcop, are you speaking of the dipole? They are about the simplest antenna to build and don't take much. You can purchased them pre made with a matching 1:1 balun off the auction site or maybe even one of the sponsors here. Great antennas for dxing! Okay for local talk and I mean local, 5 miles maybe. But a horz. Dipole even at 25ft has worked wonders for me! Look them up, 1/2 wave horizontal dipoles. You ideally want one with a matching balun to get the correct impedance. JMHO.

[1206FL]

Sorry missed the post about the wire beam. Sorry. The Internet I'm sure is full of info on how to make one.

[MDYoungblood]

MD youngblood;
I'm not trying to highjack a thread here, but where can I get more info on this wire beam you speak of?

All the guy did was mimic a 4 element beam using the dimensions of a HyGain 4 element and 8 gauge wire, the directors and reflector has to be tied together via a wire like the boom at the ridge of the roof, the driven element is independent, basically a dipole. When I talk to him I'll see if he will email me some pics and the final dimensions. BTW, it only points slightly south of west.

3's

Greg

[projectcop]

Ahha;
I kinda had an image in my head of an antenna made of wire just laying on the roof....
I've actually been looking at ready-made dipoles on that big auction site, and wondering if I could use two; one facing east-west and another facing north-south and use an antenna switch or (maybe) co-phased? Can they even be co-phased? and if so, would they need to be seperated from each other by a certain distance? Like say; one a few feet above the roof and the other a certain distance above the first? Would there be any detrimental effect of having them close together?
73's.................

[MDYoungblood]

Yes it was just laying on the asphalt shingles, I think he has stapled the wires to 2x4 treated lumber now. Co-phasing them they would need to be about 18ft apart and would give you an oblong radiation pattern, switching them using a grounded switch would turn the grounded antenna into a parasitic element and draw the radiation toward it.

3's

Greg