K4DLI and I both had LK-500NTC no tune amps that had setting for each band. The capacitors were OK but tended to arc. The space available for replacement was not very big and the ideal was to replace the capacitors with a small vacuum variable with twice the power handling capacity. Several years ago Allen Bond (MGS4U) had some almost pencil thin vacuum variables which I have seen at other sources.

I can't speak to the tape described in the October 2012 QST article but I would sure hate to be in the middle of a contest when