Cecil Moore wrote:
wrote:
I can't believe you are still trying to get Cecil to actually read the
paper he is misquoting.
Unfortunately for your lumped circuit religion, I am not
misquoting anything. Page 4 contains a test to see if a
coil falls within the limitations of the velocity factor
equation. A 75m bugcatcher coil is less than half the
upper limit.
Here's the calculation: 5*N*D^2/lamda 1
N is turns per unit length and D is the diameter.
Cecil,
Selective quoting can have the same effect as misquoting. If one goes
back a few words in the same long sentence it can be observed that the
more complete limitation is stated as:
"... an approximation for M has been determined by Kandoian and Sichak
which is *appropriate for quarter-wave resonance* and is valid for
helices with 5*N*D^2/lambda 1 ..."
[emphasis was in the original]
You apparently choose to accept the second half of the condition while
ignoring the first half. In most cases the "AND" construction means both
parts apply.
Do you really think the Vf is dependent only on the turn density and not
the number of turns? Corum never says such a thing, since the number of
turns is dictated by the resonance requirement. How far down does your
magic extend? To half the turns needed for resonance? To one turn? To
less than one turn? Where is the transition in Vf from the ~1 for zero
turns to ~0.02 for a resonant coil?
For anyone still reading who is bored (everyone) or confused by this
topic (perhaps) the importance to the subject at hand is that Cecil has
mis-used this reference paper to "prove" that the 75 meter loading coil
replaces approximately 45 degrees of the original unloaded quarter wave
antenna. After his long struggle to prove his point with modeling, and
achieving only 10 degrees of phase replacement, he abandoned that
approach for this latest futile attempt. The "missing" portion of the
test antenna is about 75 degrees, so 45 degrees would barely squeak in
under the 59% precision rule.
73,
Gene
W4SZ