On Wed, 3 Dec 2008 13:43:59 -0800 (PST), Butcherman
wrote:

Recently got back into radio after 15 year absence..... Have a
question for you antenna gurus. I want to put up a 135 foot doublet.
Question is: Does it need to be supported in the middle? The layout of
my property has no support for the middle of the antenna.
KD3Y,
I have a 220 foot dipole with a substantial amount of dacron rope
to the end supports.

I use a 40lb box of Cat Litter on one end to terminate the rope
which runs through a pulley. Although I use lightweight feeder
spreaders, the center does dip some which might affect the
resonant frequency of the antenna, I use a tuner and the
antenna "works" on all bands.

If you don't use a setup like this, it is difficult to get enough
tension and prevent the tree supports from breaking the
antenna. The antenna, made of #10 copperweld, has
stayed up through a number of NE winters.
Regards,
Ed, N5EI