speaker wire halo antenna

kc5uta

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Exploring a new antenna project concept while redoing my shack. The Halo antenna. Pretty straightforard, its a halfwave antenna thats bent into a circle, with a gap between the ends. Gives it an omnidirectional pattern. BUT THAT is where it gets interesting. how to feed it? . Most are gamma match fed. Bolt it to the mast in the center of the half wave, add the gamma, or do the "squalo" thing and use a version of the hairpin match. Then there is ANOTHER method. Speaker wire. Or if you want to oversimplify, parallel conductor wire with a constant separation. Maybe twin lead or ladder line???? I got this version from here The Hula Hoop Halo; a simple DIY antenna for 6 meter band DX Using this principle, I built a 2 meter version. Tuned easily to 144.5 mhz with a 50 ohm impedance with minimal pruning. (made sure to cut equal lengths off both sides). I then took the remainder of the 50 foot roll I was using and made another one. After a bit of trimming it tuned 17 meters. My question is .....has anybody tried this concept with 160, or 80 meters etc..? And if so, how well did it perform in your opinion? I plan on building a version for 160, 80, 40 in my pasture at approx 30 feet up, in roughly a diamond shape, or mayb a hexagon. Anybody ever try this???
6-meter-hula-hoop-halo-antenna-PA9X.jpg
 

Sheepdog777

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Exploring a new antenna project concept while redoing my shack. The Halo antenna. Pretty straightforard, its a halfwave antenna thats bent into a circle, with a gap between the ends. Gives it an omnidirectional pattern. BUT THAT is where it gets interesting. how to feed it? . Most are gamma match fed. Bolt it to the mast in the center of the half wave, add the gamma, or do the "squalo" thing and use a version of the hairpin match. Then there is ANOTHER method. Speaker wire. Or if you want to oversimplify, parallel conductor wire with a constant separation. Maybe twin lead or ladder line???? I got this version from here The Hula Hoop Halo; a simple DIY antenna for 6 meter band DX Using this principle, I built a 2 meter version. Tuned easily to 144.5 mhz with a 50 ohm impedance with minimal pruning. (made sure to cut equal lengths off both sides). I then took the remainder of the 50 foot roll I was using and made another one. After a bit of trimming it tuned 17 meters. My question is .....has anybody tried this concept with 160, or 80 meters etc..? And if so, how well did it perform in your opinion? I plan on building a version for 160, 80, 40 in my pasture at approx 30 feet up, in roughly a diamond shape, or mayb a hexagon. Anybody ever try this???
6-meter-hula-hoop-halo-antenna-PA9X.jpg
To answer your question, no. But, isn't this just a double folded dipole? Keep experimenting. Don't ever let someone tell you it won't work. The best testing kit you have in radio is the PTT Button. Keep at it!

73
AE0TO
o7

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merlin

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You need to cross connect at the gap or provide a minuscule amout of capacitance at the gap spacing.
Your diagram more closly resembles a folded dipole, but you need to complete the red and attatch the coax center to red or black, with the shield connected to the other.
An example of a halo with a gamma match:
 

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kc5uta

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That's what I USED to think. But not any more.
It took some digging, but that's when I found the "Original" halo. (referenced In the article I linked) No Gamma needed. It is still basically a folded dipole bent into a circle. I am assuming the primary difference between the two is the matching method.. easily adjustable gamma vs carefully cutting and shorting the ends, until the match is made. I'm wondering if as the frequency decreases, is the parallel conductor (aka speaker wire) going to need more distance between the two. It's fine on two meters, seemed to tune well on 17 so far. I plan to find out soon.
 

merlin

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Yes, a folded dipole in halo configuration needs no gamma match, but a true single conductor dipole in halo configuration will need some form of matching. (as in the photo I posted)
 

merlin

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I'm wondering if as the frequency decreases, is the parallel conductor (aka speaker wire) going to need more distance between the two
No, the gap can be nearly the same and with something like a rig expert or Nano VNA, you can space the gap for minimum SWR.
Old school FM broadcast antennas actually had plates on the elements to increase the capacitive reactance.
 

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