Dave,

I will definitely add a choke balun.

How much zig zagging do you think I could get away with without introducing
factors that would seriously degrade performance? My attic crawl space is
about 3 feet wide, 4feet high pitching down to the floor and 28 feet in
length. I imagine I could easily fit a 33 foot dipole in that area to work
20M.

I'd think that you could zig-zag the wire back and forth at an angle
of 45 degrees to the long axis, a foot or two above the floor, without
causing substantial degradation of performance. If you don't end up
needing to zig-zag that much to fit the 33 feet of wire into 28 feet
of space (and you probably wouldn't), zig less frequently!

Take a look at the discussion at http://www.cebik.com/zzdd.html for
some further ideas.

I imagine that your antenna's performance is likely to be set mostly
by the amount of power you can use without causing RFI/TVI due to the
strong RF fields in close proximity to household wiring. The slight
reduction in antenna efficiency isn't likely to matter very much.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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