In article ,
Bill wrote:
does any one have constructive comments about this type of aerial?

http://www.bwantennas.com/ama/fdipole.ama.htm

You can find more than you want to know about this kind of antenna,
as well as comments about it good and evil, if you google for T2FD
which means tilted, terminated folded dipole.

I use one of the B&W 90-foot antennas, not as high as I wish I had it,
but we do what we can. I haven't compared it with a single band dipole,
but compared with a Carolina Windom the latter gives about 2 or 3 S
units stronger signal, pretty much on all bands. A recent posting
I read says that the 180 foot antenna is substantially better than
the 90 foot, as would be expected.

There are some similar antennas from some other manufacturers,
Bushcomm for instance.

If you need frequency agility without retuning that is where this kind
of antenna shines. You may have to fiddle with it to get the SWR as
low as they claim. Locally one was put up at the county emergency
operations center and at first the SWR was higher than advertised.
They eventually decided this was because of all the metal in the roof
and changed it from a sloper to a horizontal dipole and that made
things much better.

Frequency agility is mostly of interest to the ALE (Automatic Link
Establishment) folks, groups.yahoo.com/group/hflink where this
kind of thing gets discussed a lot.