On Fri, 30 Nov 2007 14:29:12 -0500, "Jimmie D"
wrote:


"Tom Donaly" wrote in message
et...
Cecil Moore wrote:
Tom Donaly wrote:
And, if the total electrical length isn't 90 degrees, you
add a few degrees to the loading coil to make it come out right.
Very ingenious.

Adding or subtracting loading-coil degrees is what
happens while one is tuning a screwdriver antenna.
At resonance, the screwdriver is electrically very
close to 90 degrees in length.

Suuurrrre it is. You've got 90 degrees on the brain, Cecil.
Next, you'll be talking about 90 degree equilibrium.
73,
Tom Donaly, KA6RUH

I must be wrong too which doesnt surprise me.

Are you saying that if I put a center loaded antenna on my trucks tool box,
tune it to reonance at some freqency then the antenna is not electrically 90
degrees or some integer mutilple of 90 degrees in length at that frequency.

Some integer multiple meaning "odd integer multiple" if we are to
continue abusing this implication.

The concept that a resonant antenna could be some other electrical length is
something new to me as I thought this was the defintion of resonance being
equivalent to saying the feedpoint impedance is non reactive.


Hi Jimmie,

Basically the land-mine issue here is the hijacking of the usage of 90
degrees (or any other application of this unit) to describe a resonant
condition. That is because more frequently, and certainly more
appropriately, the usage of degrees is restricted to the physical
dimension as its significance is especially marked in relation to a
simple antenna's directivity. As you anticipate above, the simple
electrical 90 degree observation repeats through an infinite multitude
with a turn of the wheel.

There are posters who visit intermittently, and those who post
frequently that confuse the expressed electrical degrees as also
inheriting the directivity qualities associated ONLY with the physical
dimension expressed in degrees.

This might be observed through the example of a quarterwave antenna.
Its directivity is well known. If some "inventor" were to add a
lumped (or distributed) Z to the same structure, that "inventor" could
easily claim they added (for the sake of argument) 135 degrees to make
the structure exhibit the gain of a 5/8ths wave antenna. Frequently
this charade is carried out with smaller antennas being "elevated" to
full size performance (hence the appeal of the current topic in its
original subject line and the "invention" of adding coils).

With this in mind, you might enjoy how gaming the group is played out
by the more frequent poster(s) insisting on polluting the topic of
directivity with the "electrical" length. The entertainment factor
has been zested up recently by adding the term "equilibrium."

73's
Richard Clark, KB7QHC