Reg Edwards wrote:

The antenna gain of a half-wave dipole relative to an isotrope is
1.61.

What are the gains relative to an isotrope of -

A dipole with one reflector.
A dipole with one reflector and one director.
An N-element dipole array like a Yagi.

Only approximate answers are needed.

Thanking you in anticipation.
----
Reg.



In a yagi gain is not related to the number of elements (as long as
there are enough) once the boom gets significantly long. The point at
which it is significantly long could be argued to be somewhere between
1/4 of a wavelength to a wavelength, where the effect is hard to see at
1/4, and absolutely there at 1.

Are you looking for some way to reasonably predict yagi gain? If so,
there are a couple 3 equations which do a very fair job. Basically you
need one for short yagis, and another for long. If you're interested,
I'll dig the short boom out for you, but I can't right now, as I'm
already waaaay behind schedule for getting to work.

Here's the one that works best for long booms -

G = 10 log (5.4075 B + 4.25) for B GT 1

Where G is gain in dBd and B is boomlength in wavelengths.

tom
K0TAR