I once had an occasion where the bottom of a coil did get warm, while
the top did not. Yet my RF ammeters showed the same current on both
ends. What was going on?


What was he measuring, where was the coil?
W9UCW used 100 mA at the bottom, I doubt that this would "cook" the coil. You
see the pictures, they are good quality coils and he use two meters and
flippped the coil to eliminate possible error as described here.

I ultimately determined that the soldered connection from the coil to
the lower antenna mast (for experimentation, it was copper) was adding
some undesireable resistance. Solder is not a particularly good
conductor of electricity. I copper-plated over the solder joint. Not
only did the bottom section of the coil no longer get warm, but the
two RF ammeters both showed about 20% more current flowing in the
antenna. And my far-field instruments showed a 1.5dB increase in field
strength.


Again, put on the fricken Hustler 80m resonator, feed it 100W and feel it! No
meters, no hokus pokus, just "naked" antenna.


This is one example of being fooled....If you took coil temp at face
value, you would think the current taper was quite steep, judging from
the temp's of the windings. But nope...A resistive connection seemed
to be the culprit. Note that his meters showed the same current on
both ends. :/ You can see why I'm afraid of that "hook" that usually
is lurking ready to bite at a moments notice.
Don't worry, if you are right, it will come out in the end. But that
hook...Ouch.. MK


One insufficiently described measurement is enough to throw rest out of the
window? W9UCW has shown data from various measurements and positions of the
coil (pictures how it was done) and W5DXP backed it up with explanation of
reflected wave and simulation and comparison with loading stub. It came out,
this is the ned. If you choose not to believe, its a free country :-)

Yuri