has been covered by many in the past and lots of information is available
on additional antenna sites.
mind taken the answer is simple: both have their own ups and downs.
And it is your personal OPINION which will fit you the best.
There are some basic
rules to keep in mind though:
* A Quad has a
smaller turning radius then a Yagi with the same boomlenght
* A Quad has a slight higher Gain than a Yagi with the same boomlenght
(1dB not 2!)
* A Yagi is overall cheaper to build (aluminum./ fiberglass)
* There are still stories of Quads breaking up !
* A Quad has a slight lower noise level, this comes because the radiating
element is a closed circuit (a yagi with a folded dipole or a quagi
will show you the same)
* A Yagi is easier to handle / construct / maintain /
* A Quad is NOT always lighter, just imagine if ice sticks at those
wires and fiberglass poles! It becomes quite a wind catcher then as
* A few meters above ground the quad has a lower take-off angle, when
both antennas are placed high there is no difference.
* The Band with of a yagi is wider,
* A quad well tuned has a better F/B.
* There is an old ham saying which is : "with a Quad the band opens
15 minutes earlier"
I'm not in favor for the yagi nor the Quad.
I never have noticed a big difference. Those who did probably didn't
build one of the antennas right, or didn't compare correct.
It depends for me only on Physical size what to build (for stacking
yagis are easier)
This diagram is
what you could expect from your antenna, not what the manufacturer is
When compared the below diagram to the diagram in chapter manufacturers
please NOTICE that the last mentioned is in dBI in stead of the below
dBD (so +2,14dB).
The above diagram
(gain versus boomlenght) you will find figures based on real life measurements
and computer simulation.
Figures in real live could difference with what this diagram is telling,
but the boundaries are within a single dB!
Remember it is NOT
the number of elements on a Boom that makes the gain.
For its biggest part gain comes from BoomLENGHT!