You guys sure are way beyond me in antenna and trap theory. :-)

I probably neglected to mention earlier, but this antenna is for portable
operation in the field on 75 and 40 (none of the other bands are needed),
so it needs to be easy to put up and take down and easily transportable,
also fairly rugged so things like airwound coils waving in the breexe with
ceramic insulators inside the coil probably won't work; instead the coils
will probably have to be tightly wound around small lengths of PVC pipe
and lacquered in to place.

I need to build several of these antennas (at least 10, I think, perhaps
more), and so $16+ each for doorknob capacitors from places like
rfparts.com isn't likely to be practical. That reason, along with ease of
construction (and now ease of design with programs like Hamcalc around) is
why I have been leaning towards coax traps.

The bandwidth (of the traps or of the antenna itself) is not important and
so high Q and narrow bandwidth is OK.

Power levels will be low, never more than 200 watts and probably never
more than 100 watts, and often around 10 watts.

If you guys say coax traps are a sub-optimal approach I'll take your word
for it.

But, the things you all are saying about traps coming with a lot of
baggage that no one ever thought of is making me nervous. :-)

It's not exactly a new concept, trap antennas have been used with great
success for what, 80+ years now?

If I forget the coax trap idea and go with a resonant coil-and-capacitor
approach on, say, a 1.5" coil form (which Hamcalc seems reasonably happy
with after warning me that 2" was too big and 1" was too small), what
should I look out for?