Base First beam

[Greg T]

Looking to add a beam to my Arsenal and have been studying until my mind is numb. For space and wind load reasons, I've been seriously looking at the v-quad. Supposedly, 11 DB gain, roughly six or seven foot turning radius, and a 90 mph wind load survival. What I'm looking at doing is putting a rooftop Tower on the roof of one of my storage sheds and maybe an 8 or 10 ft piece of mast above that. What I'm wondering is if anyone here has any experience with the v-clad, it's performance, durability, absolutely etc. Looking for good or bad info, and just wanting to know if it would be a good investment over my Sirio 2008. All opinions will be greatly appreciated.

 

[Crawdad]

Hey Greg,
11dB gain over what? An Isotropic (dBi) or a dipole (dBd)? A horizontal dipole can show as much as 6 to 7 dB gain over the isotropic (dBi). I just modeled the dipole (Driven Element) for a 6m Yagi I built and EZNEC calculated the gain of the dipole @ 7.55 dBi. I would want to know the difference.

I know nothing about the v-quad but I do have a HexBeam on a 4' Carlson roof tower with a 2" OD x 10' aluminum mast. It's taken 50mph winds well so far. The wind loading of the HexBeam is 5 sq. ft. and the antenna weighs about 25lbs.
Hope this helps, it's all part of the equation.

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[Greg T]

Hey Greg,
11dB gain over what? An Isotropic (dBi) or a dipole (dBd)? A horizontal dipole can show as much as 6 to 7 dB gain over the isotropic (dBi). I just modeled the dipole (Driven Element) for a 6m Yagi I built and EZNEC calculated the gain of the dipole @ 7.55 dBi. I would want to know the difference.

I know nothing about the v-quad but I do have a HexBeam on a 4' Carlson roof tower with a 2" OD x 10' aluminum mast. It's taken 50mph winds well so far. The wind loading of the HexBeam is 5 sq. ft. and the antenna weighs about 25lbs.
Hope this helps, it's all part of the equation.

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I'm not sure. As with MOST MFGs, they don;t give the full info, dBd or dBi.... Here is the spec page and image"

https://www.macoantennas.net/Antennas.html

Maco V-Quad

Details on the Maco V-Quad Beam Antenna

www.macoantennas.net

 

[Henry HPSD]

Hello Greg,

Im reading 14dB gain for that 2el Delta loop antenna and 11dB on another page of the manufacturer...



Without any other information as crawdad and you have indicated.
So that leaves some room for debate

If the antenna is "well designed" you should be able to get about 7dBI freespace gain when its horizontal.

If the antenna is in the vert/horz configuration the gain will drop till roughly 5dBi for vertical and 0dB for horizontal in freespace.
So that isnt really recommended.
(bare in mind in real live the difference will be larger due to groundgain and different take-off angles... but a dipole will do the same.)

Besides the turn radius the delta loop has another positive aspect.
If the antenna is horizontal polarised and your limited in height...the antenna has a slight advantage over other horizontal antennas as the "centerpoint" of the antenna sits above the boom of the antenna.
Therefor the "electrical heigth of the antenna is actually slighly higher when compared to a horizontal yagi. This means a slightly lower take-off angle.
Im not talking about a hugh difference, but it is there.

I could imagine a situation where perhaps its just that additional heigth you needed to get clear from nearby obstacles, in that case it certainly worth a try !

Mechanical wise, no idea...hoping others will jump in !


Kind regards, Henry

 

[SuperLid]

I'm not sure. As with MOST MFGs, they don;t give the full info, dBd or dBi.... Here is the spec page and image"

https://www.macoantennas.net/Antennas.html

Maco V-Quad

Details on the Maco V-Quad Beam Antenna

www.macoantennas.net

Sounds highly exaggerated to me for a few reasons. The typical forward gain from a 2 el delta loop is around 5 dBd, in one plane. Here they allege, the antenna operates in two planes simultaneously, which would typically then halve the gain in each plane. I think a model would be more telling than the manufacturer. At least this one doesn't give more audio gain

I wouldn't expect much from the manufacturer. I don't think he knows much about antennas.

 

[BJ radionut]

v-quad =11 DB gain Over a screen door on a submarine?
The 2 Element Quad has at best, roughly 6 dB forward Gain ...compared to a 1/2 wave Dipole at same height.
Delta-Loop is a Quad...
If trying to use Dual-polarity Less Gain will be achieved...
As Henry stated.
The 2 element Quad design has about the same gain as a 3 element Yagi at same height. Here comes the fireworks!!!!
"My V-quad is 5 S units better than my 5/8th's vertical!"
Greg if you're looking for a good DX antenna to start, my HO a 4 element Horizontal Yagi is a fine choice. They can be mounted below an existing Vertical and preform very well.

I also Love the LFA style antennas (Loop fed antenna) ...
I have a 5 element on short 14 ft boom (again 6 m) ...works very well...not as well as the long boom 6, but is very quiet on RX

Forgive my laughter on gain, but here is why I chuckle.
I have a 6 Element Wide Space Yagi on a 25 ft boom for 6 meters...True max gain approx.10 dB over a dipole at same height. This is a very old design, tested on a true antenna range from early 60's. So, before the Flame-throwers start, and I burst into flames. I stand-by the info I learned from Bill Orr and others on antennas from old school designs and info before computer modeling.
73
All the Best
Gary/W9FNB

PS: Again, MHO stay away from Yagi designs using a Gamma-Match feed system, they normally have slightly less gain, than a dipole fed type design. This is due to the " forward pattern" that these designs can create. This type of feed system can warp the forward lobe on some occasions and generate nulls on the forward pattern.
OK DB/Henry/Others ...flame suit ready!

 

[Greg T]

Personally, I would go with a yagi type all day long. BUT, this would mean a free standing tower and lots of money, plus lots of labor that this old body doesn't have much of. So, I'm wanting to put the rooftop tower on a shed, but the shed is rather close to some trees and a power line about 15+ feet away. A 3 or 4 element yagi has two major drawbacks. The length/turning radius, or the height and length if mounted vertically, thinking the mast may interfere with the operation. I need something short and directional that will give me better performance than a ground plane or there's no sense in changing. Even at 5 or 6 dBd I'd be getting much better performance than a GP. For the cost, I'm fine with that. Add the rear end rejection and it's a plus. Wish I'd done this 30 years ago when I had a body left so I could use a 40' tower and climb it. But, it is what it is. More than likely, I wouldn't be using the flat side anyway. I would install it in the vertical polarization since the vast majority of folks are et up that way.

 

[BJ radionut]

2-Element HF Yagi Design - K7MEM

2-Element HF Yagi Designs

k7mem.com

 

[BJ radionut]

Chat with Chuck/KK6USY/Firerunner...he is a huge fan of the MOXON design and has built and tested many different bands and configurations from wire to tubing designs. Good Guy and very well informed on using them.

KK6USY Ham Radio Adventures

Hi I'm Chuck, on this channel I will show how I build Ham Radio related products, like Antennas, Radios, Antenna mounts. I also will share POTA and SOTA activations, Overlanding mixed with camping and Ham Radio. Also on this channel I will evaluate Ham Radio, Camping, Offroad equipment. Sound...

www.youtube.com

 

[BJ radionut]

Greg, a yagi design mounted Vertical is really going to be a challenged in your set-up. Yes, mast distorts the antennas pattern and all other antennas such as GP must be out of the elements proximity. Remember this antenna will be 16 ft long/tall etc.
You may be a good candidate to "Phase two verticals" to get desired result. Think of the old school "Super Scanner" antenna.

https://www.cgfar.com/vk3pa/images/figure_4.jpg

 

[BJ radionut]

https://www.qsl.net/ta1dx/amator/slope.jpg

These can be mounted and switchable also, and give improved directivity

 

[fourstringburn]

Sounds like you already have verticals which are good for local and DX but a horizontal beam will work better for DX if that's what you're wanting.

I recall a V quad is designed to give both vertical and horizontal patterns but I believe these are a compromise in efficiency especially compared to a separate full vertical and a yagi beam. This is fine if you just want to eliminate all your existing antennas down to having just one.

If you decide to go with a vertical yagi beam, it's better to use a 4 element so the mast will have even spacing between the center elements. As BJ radionut said, the mast does interfere with the RF pattern when used as a vertical. A three element beam is worse because it has one element near the mast and the other is offset so it's really not good to be used as a vertical.

A roof top tower with a 8 ft mast shouldn't be a problem with a 3 to 4 element yagi with no guy wires. You can also get by with just a TV rotor.

A 2 element or Moxon are much lighter, easier to put up, and will give directivity but the gain isn't quite as good like a 3 or 4 element yagi so are they worth the trouble?

 

[Greg T]

Boom length of 11+ feet and element length of 18; makes the yagi design impractical for me. That's why I was asking abut the V quad. I won't have the room to swing a 3 element, let alone a 4, if my tower goes on my shed roof. Unfortunately, I'm not as young and tough as I used to be so erecting a free-stander is out of the question. The good thing is that I'm in no hurry so I have the time to be creative and come up with something that will do the job. Is the V quad truly that bad, and that's why I'm getting a lot of other ideas? Just wondering. I knw nothing bout them. From wat I've read they can be used with eother H or V polarization, even both. I would want only vert.

 

[Crawdad]

A 2 element or Moxon are much lighter, easier to put up, and will give directivity but the gain isn't quite as good like a 3 or 4 element yagi so are they worth the trouble?

Yes. Gain over any vertical, much quieter, lightweight, easier on the wallet to buy/homebrew, easier on old backs to install.

Talking all over the planet on two elements and 100w.

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[Crawdad]

Boom length of 11+ feet and element length of 18; makes the yagi design impractical for me. That's why I was asking abut the V quad. I won't have the room to swing a 3 element, let alone a 4, if my tower goes on my shed roof. Unfortunately, I'm not as young and tough as I used to be so erecting a free-stander is out of the question. The good thing is that I'm in no hurry so I have the time to be creative and come up with something that will do the job. Is the V quad truly that bad, and that's why I'm getting a lot of other ideas? Just wondering. I knw nothing bout them. From wat I've read they can be used with eother H or V polarization, even both. I would want only vert.

Greg,
Sounds like the V-Quad will work for you. Don't let the possibly inflated gain numbers dissuade you if that's the one you think will work for you. It will still be gain over your vertical and probably quieter. Good luck and keep us posted.

PS. BJ/Gary knows what he's talking about so his ideas are worth some consideration IMO.

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