What's the best way to run a quad element dipole?

[FPR1981]

I found this on eBay and am considering ordering it, but I'm curious as to how to mount it for best performance. How do you use a quad element dipole?

Quad-element (Dipole Style) 11m CB Antenna w/1:1 Choke - All legs 1/2 wave each | eBay

It is made from high quality 18 AWG stranded insulated wire. Color of wire insulation varies. It is effectively a double full-wave, so it will most likely run at a higher impedance which would necessitate it to be fed with a higher impedance feed like twin lead/ladder line.

www.ebay.com

 

[KEWB-N1EXA]

Can always ask the seller on ebay ?

 

[FPR1981]

I did. He told me he wasn't sure, has never used one, and decided to build and offer it because it was requested.

 

[prcguy]

That tells you exactly how to mount it, which is not at all. Its not really called a quad element dipole, its called a maypole and they are supposed to be made to cover two different bands with one 1/2 wave dipole at one frequency and the other 1/2 wave dipole at a right angle to cover a 2nd harmonic band like one on 80m and the other on 40m, or one on 40m and the other on 80m. That works because only one 1/2 wave dipole is active at a time and the other is either a full wave having very high impedance and no current will flow, or its an 1/8 wave dipole and no current will flow, etc. The resulting impedance will be close to 50 ohms on whatever band is dipole is active.

The thing you have a link to has two 1/2 wave dipoles at a right angle ON THE SAME BAND. This can be done if one of the dipoles has a 1/4 wavelength phasing harness between them, which will make it a circular pol antenna or an RF transformer that has a 50 ohm input and 25 ohm output to feed the two dipoles in parallel because two dipoles in parallel. But the one in the link is neither because the builder has no clue what he built and he is hoping you will buy it anyway.

I did. He told me he wasn't sure, has never used one, and decided to build and offer it because it was requested.

 

[a417]

I did. He told me he wasn't sure, has never used one, and decided to build and offer it because it was requested.

He twisted the wires together and slapped a big 'ol price tag on it. @prcguy is right, you don't touch this one.

 

[prcguy]

I just read further into the description, "All 4 elements are a half-wavelength each, all measuring approximately 17 feet, 4.2 inches (17' 4.2”) each". So basically that antenna can never work because it has two center fed dipoles of very high impedance each in parallel, giving a really high feed point impedance. I wonder how many he sold and how many buyers asked WTF is going on with their new antenna?

 

[KEWB-N1EXA]

I did. He told me he wasn't sure, has never used one, and decided to build and offer it because it was requested.

WOW $50 With a tail light warrenty...When you dont see the Fed Ex trucks tail lights your on your own!

 

[FPR1981]

Excellent, guys! Thank you! Precisely what I needed to know

 

[KANE4109]

Uhhhhh.... something sounds weird here. It does look like he is using 4 - 1/2 wave elements which.... just makes me itch.
But then....... TWO of them attach to the center conductor...... the OTHER TWO attach to the ground/shield side. It sounds like a dipole over a minimal ground plane. What the Hell????

I'd keep my money in my wallet.

 

[prcguy]

Yes, a maypole is two parallel dipoles at right angles with a common feed point but they would be half wave center fed on two different bands and not two full wave center fed dipoles with a common feed.

Uhhhhh.... something sounds weird here. It does look like he is using 4 - 1/2 wave elements which.... just makes me itch.
But then....... TWO of them attach to the center conductor...... the OTHER TWO attach to the ground/shield side. It sounds like a dipole over a minimal ground plane. What the Hell????

I'd keep my money in my wallet.