dave
shared these priceless pearls of wisdom:

-Ok that brings an interesting thought,
-When building a multiband antenna, multiple elements can be attached to
-the same feed point and the element cut closest to the resonant freq
-will radiate.
-I did this with an old HF radio for 20, 40 and 80M.

Yes, but you will clearly note that you did not run the elements very close
together, or you might just as well have used a single piece of wire. The
elements were separated, and the more separation the better the multiband
antenna worked.

However, here you are working with a single frequency, and if the wires are
spaced roughly a wire diameter apart, the apparent bandwidth is outrageously
good.



-Also, I read that should I use a torid (SP) and put a loop of coax to
-keep reflections down.

Most folks that use toroids as baluns (actually as chokes) use a toroid that
just slips over the coax and a couple-three of them close to the antenna. This
makes a single-turn coil for each toroid. If you've got the room to use a large
toroid and several loops through it, go for it. Embedding them in the structure
doesn't allow me to do my designs like that {;-)

Don't forget -- the toroid material must be "good" at the frequency of interest,
or all you've done is put a steel nut around the coax, and not a choke.

Jim
Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com