[NLRS] Favorite horizontal loop design?

[Paul Beckmann]

I'd like to make up a stack of 3 horizontal loops for 6, 2, and .7
meters and am wondering what tried-and-true designs the NLRS crew
might recommend. I'm especially interested in matching section
designed used. I'd also like any advice on spacing that will keep me
out of trouble. I'll likely build all of them out of copper
pipe/tubing for fixed outdoor use. Not anything for great performance,
just to have weak signal capability from the home QTH.

73
--Paul, wa0rse -- EN34kv