On Mon, 4 Apr 2005 16:02:04 -0500, "Ken Bessler" wrote:

My friend says that a double bazooka is 98% efficiant
and that a dipole is only about 70% efficiant.

Is he right? Will a double bazooka outperform a dipole
enough to notice a difference on 40m?
Hi Ken,
Those who tout the double bazooka have been misled for eons. That antenna is
simply a resistance-loaded dipole and the increase in BW is due to the
resistance loading of the dielectric in the coax that forms the dipole. The
shunt reactance of the shorted quarter-wave sections forming the dipole does
nothing to increase the BW. The principle is ok, and was used on military
equipment during WW2, but for the shunt reactance to provide the increase in BW
the feedline Zo needs to be at least two times the resistive component in the
dipole input impedance for the concept to work. Consquently, the double bazooka
as misused by the amateur community has been misengineered.

I published a long and detailed expose of this antenna in Ham Radio, August
1976, with a shortened version in QST, Sept 1976. I explain mathematically why
it doesn't work as many claim. It appears as Chapter 18 in Reflections 1 and 2,
and is available for downloading from my web page at www.w2du.com. Please review
this document before wasting your time and energy on a dud.

Walt, W2DU