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Quad dimensions

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Subject: Quad dimensions
From: (Rod Fitz-Randolph)
Date: Sun, 5 Jan 1997 00:00:36 -0600
On 4 January 1997, Paul, W5DM, wrote:
>I have read with interest your postings about quad dimensions.  Way back in
>April l958 QST published in Technical Correspondence (page 47) a letter that
>I had sent them the latter part of 1957.  To my knowledge this was the first
>publication in the ham literature questioning the then accepted formula for
>the length of wire needed in a quad.  On a homemade 20m quad I came up with
>250/FMc for the length of one side of the quad--which translates to
>1000/Fmh.  Using your correct 1004/Fmh yields an error of 0.4%
>for my measurement.  Not bad for a homemade GDO and resistance bridge--and
>an old BC-348 receiver!
>Also, I did not know that Dr. August Raspet worked in the field of radio.
>My good friend and fellow soaring pilot (very famous soaring pilot) Dick
>Johnson of Dallas, TX did a master's degree in aeronautical engineering
>under Dr. Raspet in the late l940's or early l950's.
>Again, I have enjoyed your postings.  Good luck.
>              73, Paul, W5DM (in 1958 W5GGV)    email:
Paul, I hadn't realized that there had been any other duplicate discoveries
of the proper dimensions here in the U.S. until I received your message.
Congratulations on having found that out in 1957!!!  It looks like we both
"re-discovered" the wheel that the two Japanese determined in depth in 1956!

August (Gus) Raspet was a cantankerous and wonderful old genius with a PHD in
Aeronautical AND Electrical Engineering.  I was a EE student in 1958 when I
for him in his labs there at Miss. State.  He was hell-bent to find a
polarized antenna that would radiate in all directions from an aircraft.  He
gave me orders to determine such an antenna!  In my ignorance I thought that a
loop antenna, mounted under the belly of a light plane (aluminum skin
aircraft) about 4 inches from the belly of the craft, might provide the
polarization in all directions.... was I ever wrong!  But in the process of
attempting to create such an omnidirectional polarized antenna, I made
of all the parameters of such an antenna. I and two other students (I was
the only
ham operator among the three of us) discovered that (using an calibrated RF
Admittance Meter) the antenna was only resonant when it was made according
to the formula of 1004/Fmhz=lenth in feet! I went around Miss. State asking all
the EE PHDs, that taught there, for an explanation.  All I got was some
answers that antennas were primarily empirical.... that it was all smoke and
mirrors.  None could supply a proper answer.

I immediately started to apply that formula to the quads I built, with great
success.  The rest I've stated in a previous messages.  I thought I had really
contributed something to the world!!!  You can imagine the let-down when Dr.
Bill Osborne (an Electronic Scientist at Harris Corp.- then Radiation, Inc.,
and a kick-around ham radio buddy and fellow contester) became most interested
in the genesis of the dimensions and, upon investigation in 1970, found that
two Japanese had made exhaustive measurements of full wave loop antennas in
and come up with the same formula... Again, all we did, Paul, was to re-invent
the wheel...  It was sure fun doing it, tho!!!


Roderick M. Fitz-Randolph
79 Highland Hills Cove,
Jackson, TN  38305
(901) 661-9278 (Phone - after 10 AM and prior to 9 PM)
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