"Alex" wrote in message ble.rogers.com...
Has anyone tried building a 1/2 wave coaxial sleeve antenna for 40m? I have
a large tree with a branch at 70' and i thought i'd pull the antenna up with
a rope. Should i make the sleeve out of copper pipe? A 1/2 wave vertical
would be a nice antenna for 40m and i thought a coaxial sleeve antenna would
give me a great feed impedance. Any thoughts? The coax are 100' of RG8.

Myself, I would probably feed it from the base. One problem often seen
with sleeve dipoles like that is decoupling the feedline from the
antenna. if you do center feed it, pay close attention to feedline
decoupling. MK