On 07 Feb 2004 18:43:31 GMT, oUsama (Yuri Blanarovich)
wrote:
They are NOT resonant at the frequencies of interest
That is like saying the coil in a tank is not resonant by looking at
the coil alone.
Coil in a tank (with Cap) is not resonant on the same frequencu as "naked"
coil. Big difference where it resonates.
What a myopic way of looking at antenna design.
My what?
Loading coils are SERIES RESONANT, traps are PARALLEL RESONANT.
Uh, huh! Bulsheet! If the COIL is self resonant (on frequency of interest), it
becomes trap.
The only difference is where the capacitor is. For a loading coil,
the capacitor is made up of the reactance of a too short antenna. For
a trap, there is a literal capacitor, AND the reactance of the
antenna.
And there is huge difference how the coil works in a circuit!!!! It could be a
loading coil, or it could be a trap. That's why there are different names for
it.
If the antenna had no reactance, there would be no need for the
loading coil (unless it is your next patent-applied for snow removal
device).
More W8JI rhetoric? Maybe time to grow up?
73's
Richard Clark, KB7QHC
Using your jabs Richard, I would say that you are off the wall, rocker, tree,
you name it. You are displaying lack of proficiency, understanding, basics,
etc.
He was talking about the COIL. Coil without "capacitor" made of antenna or rest
of the radiator.
LOADING COIL is a COIL - that's it. Coil will resonate rest of the antenna with
its whatever reactance. But coil by itself will resonate somewhere else,
depending on its internal capacitance. But definitely not on the resonant
frequency of the ANTENNA. If it did then it would be a TRAP. And that is the
difference, and that was what was asked.
Loading COIL is not reasonant on the frequency (of interest) that we want
antenna to be resonant on (unless using it as helical antenna), otherwise it
would act as a TRAP and insulate the remaining portion of the radiator and make
the portion of radiator up to the trap (coil) resonant on frequency
corresponding to its (electrical) quarter wave length.
If you can not comprehend the difference between the LOADING COIL and TRAP than
rest of the discussions here are pointless and you should go back and re-read
some books (how do you like that? :-)
Yuri, K3BU.us
Warning! I bite back!