On Oct 17, 9:52*am, K1TTT wrote:
that doesn't really 'solve' it, that just provides a single big
shorted turn instead of many turns.

Maybe the single big shorted turn IS the solution? :-) When there are
no actual shorted turns, i.e. all of the coil is exposed, does the
bottom section of aluminum tubing become that same single big shorted
turn? In any case, one very conductive and very wide shorted turn is a
lot less lossy than a number of small shorted turns.
--
73, Cecil, w5dxp.com