[Elecraft] OT antenna question -- solved, soon to be fixed

[Clay Autery]

Interesting.  My SWAG was the obvious transmission line/feed point
impedance mismatch, but I would have never thought about the fasteners
being the issue.
I'll be reading up on eddy currents now and how they apply to impedance.
Is it possible that it's not actually the ferrous materials and the eddy
currents generated, but the mating of dissimilar metal conductors
separated by a thin layer of aluminum or other oxide setting up some
level of capacitance, and/or some additional inductance added by the
stainless fastener and feed-line attachment (a 1-turn inductor?)?

All that put together in some freak fashion would lead me to believe a
small L-C network was created that may have caused a transmission line
to antenna impedance mismatch uncorrectable at the station... indeed,
under-reported in the SWR readings.

Just a huge guess and just curious.  Adding this to my "file drawer" of
troubleshooting ideas, but I'd like to understand the science.

Of course, it could be simpler...  simply multiple interfaces of
sufficiently incompatible metals that it sets up galvanic corrosion in
multiple layers.

> ...The trouble was at the connection of the feedline to the antenna.
> (...) I think that it was due to the ferrous material (stainless
> steel) of the bolts heating due to eddy currents in the strong RF field.
>
> I will change the method of connecting the line on Sunday and I hope
> it will solve the problem.

Assuming the root cause is galvanic corrosion (and potential
introduction of capacitance and/or inductance), I would surmise the
solution to be setting up a connection where no two incompatible metals
are touching.
Something like a bi-metal connector kinda like the one on this page
(only correctly sized):  http://www.utilex.com/bi-metallic_connector.htm

If I'm way, way off base, please educate me.  I'm on this list to learn.

73,

______________________
Clay Autery
(testing 02/20/16)