The reality is that current is different, Eznec can't model it, ...
Yuri, have you read Wes's article? Using wire segments, he modeled a loading
coil in EZNEC. His segmented wire model of a coil shows a current taper
through the coil. It's on his web page at: http://www.qsl.net/n7ws
You can also download Wes's zipped EZNEC files.
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73, Cecil http://www.qsl.net/w5dxp
Sorry!
OK, I will be more precise:
Eznec can't model current through zero physical size, but certain value
inductance inserted in the antenna element. (As W8JI shows on his web page
modeling his mobile antenna, "proving" that current is the same :-)
If the inductance is modeled as coiled wire with numerous segments and proper
physical dimensions, then the current is modeled and reflects the reality.
(Tough to do modeling typical loading coils.)
How's that?
Sorry I got pulled into the simplificity :-)
LB Cebik on his web site also has an example of coil modeled using segments and
it shows current drop.
I hope it warms up, so I can get out, dig the car from the snow and do some
experimenting.
First experiment will be with 80m Hustler coil in order to use "standard"
(lousy) typical coil. I will paste LCD strip thermometers on the coil to
measure temperature changes at various positions, ends, middle.
Experiment #1:
I will drive DC current through the coil in order to generate heat and observe
the temperatures across the coil. I predict that thermometers will be tracking
each other very closely or be identical (ideal case).
Experiment #2:
I will insert the same coil in the Hustler mobile antenna, tune to resonance
and fire 100W to it. I will observe temperatures between the end and center and
between two ends. I expect difference indicating difference in current at
various points.
This will be the least disturbing measurement setup, no conductive nothing
disturbing the coil or antenna. I am assuming LCD thermometer is RF transparent
and I will verify that it does not detune the antenna/coil. Perhaps not very
accurate, but sufficient to demonstrate the debated differences.
The next measurements will be with current probes and RF ammeters. This will
give more accurate values.
Any problems with that?
Yuri, K3BU.us