[TowerTalk] 2000 Antenna Forum Speakers

[Jim Reid]

Hi Guys,

Well,  the  reason I commented about Dr. Best's earlier
presentation had to do with his premisses.  He has analyzed,
exhaustively a situation where the mismatch was
causing an 8:1 vswr -- not really very typical of most
of our amateur station set ups,  unless we are running
to a random length dipole and using a tuner.  However,
his claim is that he must use such a great mismatch
to bring the numbers up to where they are calcuable
with his math.

He then proceeds to calculate voltages throughout
the system;  but he failed,  at least in the early papers
and e-mail discussions I have seen about his work,
to account for propagation time in the transmission
line.  He,  it seemed to me,  would hypothesize a
voltage caused by mismatch at the load,  and then
state that this was the (instantaneous) reason for
something happening back at the source terminal,
for example -- just isn't so.  Now,  perhaps I mis-read
his intent,  or what he was doing, as to understand
what he was saying/writing takes some digging.

Now that is what I hope becomes more clear during
the forum at Dayton.

Second issue is the subject of the conjugate match
and Best's sseming lack/dismissal of that topic
which has generated the huge debate between
Bruene and Maxwell,  even resulting in the ARRL
withdrawing Walt's book from print,  and removing
much of what W2DU had written in several editions
of the Antenna Book,  and the Amateur Handbook.
Walt has been working diligently these last few
years to attempt satisfactory mathmatics for his
critics;  I have had the opportunity to review certain
parts of Walt's work of the past couple of years,  and
look forward with anticipation to the publication,  I guess
now,  later this year.

And this brings me to the third issue:  Bruene's quarrel
or arguments about the unusually high vswr load he
claims tube linear  amplifiers want to see.  He 
has published a few times about this topic both in
QST and CommOuartly.  And some of us still don't
really understand what he is doing/measuring.  But
still,  because of that work,  Maxwell's work has been
accepted as discredited,  at least by the ARRL tech
folks.  At least that is the way it seems to me.

Because of Bruene's efforts,  and his denial of Walt's
use of the conjugate matching theorem, there is much
more which ought to come up during Best's section of
the forum than simply the various views of the amount
of added loss caused by load mismatch!  I feel the
title of Best's intended paper seems to imply that some
of this other material/topic areas might be covered,
at least I hope so.  And that some of the principals
in this long lasting conversation might also be present
to participate in the discussion/question period to follow.
Of course,  this might be cut short because of time limits.

In the case of an antenna load Z being different from the line
Z,  can the system "antenna tuner"  be ascribed the properties
of a conjugate matching device, per Maxwell's work,
or as Bruene claims,  and Best claims to show by his
analysis,  that it is only an instantaneous voltage/ impedance
matching device??

Until Dayton,

73,  Jim,  KH7M




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