Coily 5 Beam

[Drifter]

That feed system looks awesome. I wonder how it performs.
coily 5 Beam

 

[RatsoW8]

It's a quad so it probably performs well like a quad should.

 

[dxhound]

Where do you get quad from that link???? Its a single polarity Yagi

 

[Shockwave]

Some things I noticed on that 5 element beam is I have never seen such a large length difference in the elements on any antenna other than a log periodic. This can't be producing close to optimal gain but it may be helping with front to back rejection. Also, the T match is an improvement over the hair pin from both a mechanical standpoint and performance. You have no insulator in the middle and both sides of the element are driven from the center conductor of the coax. Tying the braid to one side of the element never reduces coax radiation to the degree the T match does. The best place for the braid is to ground it to the center of the driven element where there is no RF voltage. Anything else is a compromise.

 

[33 the kid]

wonder what he charges for one, man it looks real heavy

 

[serrasalmus]

that looks like something i could put up with my normal north winds of epic nature...looks very strong

 

[555]

whats a so-239 and a pl-259 connector rated for

 

[W5LZ]

Shockwave,
I've never seen a 'T' match on an antenna. I'm aware of what a 'T' impedance matching network is, but that's not the same at all. so what does a 'T' match like you are talking about consist of?
- 'Doc

 

[Captain Kilowatt]

I thought it was a beta (Hairpin) match with a balun attached. What makes it a TEE match instead of a Beta match? I must have missed something.

 

[Drifter]

wonder what he charges for one, man it looks real heavy

I would like to know too. Gonna send him and email. The spec says it weighs 42lb.

 

[Captain Kilowatt]

I had another look. It is a Beta match. A TEE match looks like two opossing gamma arms that are tapped along the element length. This match is fixed at the feedpoint but has adjustable length making it a Beta match aka hairpin match.

 

[W5LZ]

A Beta (hair pin) I'll believe. Whatever it end up with, it looks like it's very sturdily constructed.
- 'Doc

 

[gamegetter]

i agree he moved from a gamma(seen in some pictures) to the beta with a balun.

i made one of these hairpin betas for a beam back in the 80's and although i could not measure it, i believe it helped my signal out quite a bit, i believe it helped focus it better, if that makes any sense.

just my opinion

 

[Captain Kilowatt]

I made a six elenent 6m yagi and used a Beta match with a coaxial balun. It worked great. The attempt to build and tune a gamma match was a disaster.

 

[W5LZ]

I think that if the matching device, beta, gamma, whatever, is done correctly there will be some very slight differences in performance and 'losses'. I don't think those differences are going to make a huge difference. If it does, then I think taking another look at the whole thing would be wise, cuz sumpthin else is wrong. I think the practical side of it, which one is more 'practical' for you for whatever reason, is a pretty good way of picking which one to use.
- 'Doc