On Fri, 07 Mar 1997 12:09:31 -0800 Ken Lopez <kjlopez@earthlink.net>
writes:
Dear Ken,
you wrote:
>Cecil A Moore wrote:
>
>> A convenient length of open-wire feeder is 84 ft.",
>
>Why did he consider this length convenient?
>
>Ken, N6TZV
>
>
This length produces 51+84=135 feet total each side. Combined length
produces impedance like full wave center fed antenna for 80m... 2 wave
length on 40m... 4 wave length on 20m etc. It also makes the antenna
more manageable on 15m. Louis himself expressed that his original G5RV
design was NOT intended for operation on 15m.
However, once one replaces the ladder line/coax combo that made the
antenna famous with a run of strictly ladder line, then one no longer has
a G5RV. They have an 102 foot center fed dipole tunable to just about
anywhere with the right matching system. But there is nothing to
distinguish it from any other similar antenna system using different
lengths. Naturally, the pattern is affected by changes in antenna length
and frequency of operation... as do the matching requirements. These
antennas will all perform well if proper care is taken in their
construction and use. But they are not G5RV's anymore.
By the way, up until a few years ago, Louis was still very active on the
air. I had a chance to work him on 15m and we had quite a laugh because
I ribbed him about his antenna being 'lousy' on that band. He had a
great signal so he laughed and said, "That was in the days before
auto-tuners..."
His bright yellow-orange QSL is one of my most cherished ham radio
treasures. I have also heard Louis from his QTH in CX land but I never
QSO 'ed him from there. I didn't feel it was fair to 'hog' a celebrity's
air time. Who can argue with the fact that Louis devised an antenna
scheme that has become the second most popular wire antenna... after the
half-wave dipole... in our Ham Radio world?
Another fact that Louis reminded me about was this. He designed the now
famous G5RV antenna to be fed from a wide range Pi-network in his
transmitter. He wanted an antenna design that his xmitter would load
into without an external antenna tuner. The irony is that his antenna
has become vastly popular in an era when Pi output's are no longer common
in our transceivers. Could it be as Louis said... the auto-tuner became
his antenna's best friend?
I hesitantly agree. As you all know... their are a lot of auto-tuners
out there that don't think much of the G5RV... especially on 80 meters.
But what a great antenna on 40, 20 and 10! My hat is still off to Louis,
G5RV. Long years after Louis... and all of us... have gone on to the
next life... and our calls are all forgotten... or reissued to new
QRPers... the call G5RV will still be on someone's lips... a whole lot of
"someone's"
vy 73,
Martin W9XN QRP-L #998
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