[TowerTalk] Hi-Tech Station Cost (>QUADS)
K3BU@aol.com
K3BU@aol.com
Thu, 25 May 2000 11:11:45 EDT
In a message dated 5/25/2000 9:19:56 Eastern Daylight Time, n4kg@juno.com
writes:
> > There's a lot of information in the literature and it's becoming
> > more difficult to ascertain what is valid and accurate. In the past
> > week, I have discovered as much MISINFORMATION concerning
> > the performance of quads v. Yagis as I have with respect to
> > transmission line theory. I suspect that much of the inconsistency
> > through the years can be attributed to a lack of
> > standardized and generally-accepted measurements and procedures.
Based on my experimental work with Quads, Yagis and combinations of Q-Y I
have found that up to 3 elements, Quad beats the Yagi, around 4 el. they are
about the same, 6 el. and up Yagi takes over. Here we are talking gain, and
not other factors like being more quiet, etc.
The rule I have come up with is like this: It is a waste of hardware to go
over one parasitic quad element on the front and behind of driven Quad
element (or log cell). Quad element is low Q and does not do as well as
parasitic element, as higher Q Yagi dipole does.
So quads with more than 4 elements are waste of hardware (unless you phase
them properly).
Another finding was that with longer boom antennas, it is beneficial to use
log driven cell, improves pattern, F/B and gain.
Another surprising finding was that extra Yagi reflector on long Razors
contributed more gain up front than another director 3x spacing would have
contributed.
You can see the real thing (two stacked 7 el. 15m Razors) as it was on the
cover of CQ mag. at <A HREF="http://members.aol.com/ve3bmv/index.htm">VE3BMV
Home</A>
One has to be careful what is compared, good 3 el. yagi can beat poor 4 el
quad and vice versa.
Operator vs. hardware? Sure, lousy op with super station can be beaten by
super op with lousy station. But then super op with super station can beat
all of them. And that's the name of the game. This is why I am never
satisfied with commercial "junk" and look for ways to beat that (modified
radios, home brewed amps and antennas).
See you all in wpx cw from VE3KZ as training for WRTC.
Yuri, K3BU, VE3BMV
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