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Re: [TowerTalk] 6 mtr quad

To: sawyered@earthlink.net
Subject: Re: [TowerTalk] 6 mtr quad
From: "Joe Giacobello, K2XX via TowerTalk" <towertalk@contesting.com>
Reply-to: k2xx@swva.net
Date: Wed, 31 Aug 2016 13:44:25 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Ed, I have been using quads since the late 70s. My first one was a Skylane tri-bander, which used low strength, flimsy spreaders compared to what's available today. I've also had a couple of six band quads with four elements on 10-20M and seven on 6M with a 24 foot boom. They do indeed work well and, when multibanded, are far less of a compromise than multiband Yagis. A 2 element quad has only about 0.3 dB less gain than a three element monoband Yagi. Going to multielement quads beyond three elements is an exercise in rapidly diminishing returns. The gain increase is relatively small given the increase in expense, complexity and vulnerability. Four element Yagis and beyond are then a better investment.

I am currently using a two element duobander on 30 and 40M on a 20 foot boom. It's almost equivalent to a three element monoband Yagi but on a far shorter boom. Cubex's 26 foot spreaders have held up well at this windy QTH, although the combination of ice and wind can be destructive.

73, Joe
K2XX

Ed Sawyer <mailto:sawyered@earthlink.net>
Wednesday, August 31, 2016 9:16 AM
The Quad vs Yagi debate is timeless. I always thought there were a number
of things contributing to it:

- Back in the day before computer optimized gain yagis, the quad
was a simpler way to get more gain on a given boom. The full loop started
it off with something like 1.3dB gain over the dipole element and placing
evenly spaced elements gave good results for a 2 or 3 el quad.

- The average height of a quad (I have to believe) is the center
point between the top wire and the bottom wire (or diamond tips) so the HFTA
analysis should be the same for a yagi vs a quad at a given height when
horizontal polarization is used.

- However for the early years, low "towers" of 30 ft or so, if they
were fed for vertical polarization and happen to be in a good to excellent
ground conductivity area, the take off angle was likely better for long
"band opening" DX and impressed their owners.



Today, there is much better ability to get maximum gain out of a longer boom
yagi that is way easier to install and maintain and we understand the take
off angles much better.



I could be wrong on the above folklore, but that's my guess.



Ed N1UR

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