The bolt in the coil bottom is a standard 1/4-20. It is a
trivial matter to make a transition part.
Or, to drill out the hole and tap 3/8-24. Should be enough
stock left for that (though I think I'd prefer not to do it
with a hand drill).
Getting back to the bigger topic, though, as someone
mentioned, I think it is fair to say that the AP-10A is not
a magic bullet. The coil may have slightly higher Q and the
instructions may help getting it tuned faster, while the
MP-1 is more compact and has nice mounting hardware. Both
need care and skill to get predictably good results.
I bought some 3/8 aluminum rod stock last night and am going
to make up a couple of extension rods for experimenting with
the MP-1.
73
John Newell
KB1FPM
