People have an extremely strong tendency to simplify the mass of
incoming data into simply digested and understood binary categories: Is
it good, or is it evil? Does the antenna work, or doesn't it? And here
the binary choice is between a 136 foot dipole and a shorter dipole.

The answer here, as it is to so may binary questions, is that it behaves
in some ways like one, some ways like the other, and some ways like neither.

The helically wound antenna can be made resonant. A 136 foot dipole is
resonant, but a shorter dipole isn't, unless loaded.

It will be inefficient, which is also usually characteristic of a short
dipole and not a 136 foot one. A short dipole with a properly designed
matching network could be made to be more efficient than the helically
wound antenna.

The input resistance at resonance will be between that of a 136 foot
dipole and a straight dipole the length of the helical antenna, unless
the loss is exceptionally high.

The bandwidth will be between that of a 136 foot dipole and one the
length of the helical antenna, unless the loss is exceptionally high.

The pattern will be more like that of a short dipole than that of a 136
foot dipole, although you wouldn't be able to tell the difference. It
would even be hard to measure using professional equipment.

Roy Lewallen, W7EL

James barrett wrote:
Hi, I just read instructions on building a "helically wound" antenna
using a broom stick.
http://www.hard-core-dx.com/nordicdx.../bromstik.html

After reading this, I had an idea. I'm doing more google searches for
this type of configuration, but wanted to ask here as well to get some
opinions. What if I took two broom sticks, and wound each with about
68 feet of wire. Each stick making half of a dipole antenna. Then
attach 450 ohm ladder line (or 50 ohm coaxial). How would this behave
when connected to a tuner? Would it behave like a 136 foot dipole, or
would it behave like a shorter dipole?

Jim