OK, I have been accused of being wrong, claiming that current across the
antenna loading coil is or can be different at its ends.
I and "my camp" say that we are seeing somewhere 40 to 60 % less current at
the top of the coil, than at the bottom, in other words, significant or
noticeable drop.
W8JI and "his camp" are claiming it can't be so, current through the coil
has to be the same or almost the same, with no significant drop across the
loading coil.

Let's start the fresh thread and trace step by step where I went wrong.

Just reminder that we are talking typical situations, as for example real 40
m (or 80 m) mobile whip with loading coil about 2/3 up the radiator. We are
talking about resonant electrical quarter wave monopole. We are talking
about standing wave RF current that can be measured with RF ammeter and is
shown and plotted in modeling programs like EZNEC.

Here we go:

wrote in message
Let's focus on one thing at a time.

You claim a bug cather coil has "an electrical length at 4MHz of ~60
degrees". That concept is easily proven false, just like the claim a
short loaded antenna is "90-degree resonant". Both can be shown to be
nonsense pictures of what is happening.

Assume I have a 30 degree long antenna. If the loading inductor is 60
electrical degrees long, I could move it anyplace in that antenna and
have a 90 degree long antenna.

We all know that won't happen, so what is it you are really trying to
say?

73 Tom


OK lets get me some educating here.
I understand that, say quarter wave resonant vertical (say 33 ft at 40m) has
90 electrical degrees.
Is that right or wrong?

The current distrubution on said (full size) vertical is one quarter of the
wave of 360 deg. which would make it 90 degrees. Max current is at the base
and then diminishes towards the tip in the cosine function down to zero.
Voltage distribution is just opposite, min at the base, feed point and max
at the tip. EZNEC modeling shows that to be the case too.
Is that right or wrong?

If we stick them end to end and turn horizontal, we get dipole, which then
would be 180 deg. "long" or "180 degrees resonant".
If not, what is the right way?

If I insert the coil, say about 2/3 up (at 5 ft. from the bottom) the
shortened vertical, I make the coil size, (inductance, phys. dimensions)
such that my vertical will shrink in size to 8 ft tall and will resonate at
7.87 MHz.
I learned from the good antenna books that this is still 90 electrical
"resonant" degrees.
Maximum of current is at the feed point, minimum or zero at the tip.

If you stick those verticals (resonant) end to end and horizontal, you get
shortened dipole, with current distribution equal to 180 degrees or half
wave. Max current at the feed point, minima or zero at the tips. (RESONANT
radiator)

How many electrical degrees would that make? How do you arrive at that?
Why is this a nonsense?

Can we describe "pieces" or segments of the radiator as having proportional
amount of degrees corresponding to their physical length, when excited with
particular frequency?

If I can be enlightened about this, we can go then to the next step.

Answers, corrections please.

Yuri, K3BU