Sure hate to jump into this, but I've used a number of good tuners over the
past 28 years (and a number of lousy ones) with 100% homebrew antennas. You
"tune" a feedline, in a relatively traditional fashion, by shortening it or
lengthening it. That is more-or-less what occurs within a tuner (transmatch, or
whatever) as more or less coil (length) is added or subtracted and some
"tuning" by length adjustment is taking place.
So the antenna really is actually "tuned" (at least a little, for what that
really matters). It is effectively lengthening or shortening the antenna
somewhat by adding coil length in or out, in a manner similar to adding in a
length of wire or coax (or a loading coil), thus effectively adjusting the
antenna for length slightly (and at the same time, adjusting it for final
impedence seen as the impedence changes with length).
The balun effects an additional impedence change, and that also "tunes" the
antenna (for want of a better way to state it) from an impedence matching
standpoint. That's why sometimes a 1:1 balun works and sometimes a 4:1 balun is
required (so that the final impedence seen can fall within the matching range
of the particular tuner).
It's all in what someone wants to call "tuning" and, whatever or however you
want to explain it, "tuners" (transmatches, or whatever) allow a load to match
the impedence the rig wants to see so that power can be transfered to an
antenna.
They work, but that said, they are also not the answer to sloppy antenna
design, and I think that is where a lot of the personl polarization regarding
the effectiveness of them comes from. The end effectiveness of any antenna is
going to be related to wire diameter, length, wire type, connections, height
above ground, etc. - all the things that always affect any antenna's impedence
or effectiveness. If what is there is outside the adjustable range of a tuner,
no matter what tuner it being used, it simply won't work well. If it is within
range (and the antenna is of some solid design and the tuner is reasonably
efficient), it will. A tuner might match any length of coax (or whatever
feeder) into a good dummy load, but that doesn't make it an antenna.
Some guys have had great results with "tuners" - some don't. I have had (and
I've also designed antennas that could not be matched). Depends on so many
factors that I feel this type of community polarization has taken place over
the years simply as a result of how effective (or ineffective) the results have
been for the end user. What you can it, to me, is inconsequential.
One opinion. Mine. Works for me.
Mike
k5wmg
one watt all the time
---------- Original Message ----------------------------------
From: "mgoins" <mgoins@mail.ev1.net>
Reply-To: <mgoins@mail.ev1.net>
Date: Mon, 5 Dec 2005 12:00:15 -0600
>Search engine for Austin/Dripping Springs
>
>http://www.escapesomewhere.com/
>
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