http://www.arising.com.au/people/Hol...ph/counter.htm

"Vito" wrote
http://www.arising.com.au/people/Hol...ph/counter.htm

Thank you, it was very interesting, but it states in part:

Figure 2.0 illustrates the efficiency for various counterpoise systems and a
dipole above ground.
---
Actually, it only shows the effects of running a counterpoise under a dipole
erected so close to the ground that it could never work properly (without a
counterpoise). It is no help in determining if adding a counterpoise under a
dipole that is already higher than one quarter wavelength above ground would
help or not. If dipole efficiency is already between 90-100%, then the
findings appear inconclusive as to whether any gain would be realized, ie:
the 1.64 factor that might be possible from a perfect dipole with minimal
earth-losses.

Jack

Jack Painter wrote:


Figure 2.0 illustrates the efficiency for various counterpoise systems and a
dipole above ground.
---
Actually, it only shows the effects of running a counterpoise under a dipole
erected so close to the ground that it could never work properly (without a
counterpoise). It is no help in determining if adding a counterpoise under a
dipole that is already higher than one quarter wavelength above ground would
help or not. If dipole efficiency is already between 90-100%, then the
findings appear inconclusive as to whether any gain would be realized, ie:
the 1.64 factor that might be possible from a perfect dipole with minimal
earth-losses.


0.25 lambda = 40 m or ~130 ft on top band. Few of us have top band antennas
that high. Did you not notice the working frequency of 1.825 MHz?

If your antenna is already 90-100% efficient it seems fairly obvious that
there is little more to get without sacrificing omni directionality.