All,

A fundamental basic question, which is the primary purpose of radials:

1. is it to create a ground, that is a as close as possible to zero ohm virtual
reference for the 'real' vertical half of the dipole?

2. Or are they to create a real resonant half of a dipole?

If it is the first then what does the 'efficiency' curve look like for a
shortened, loaded, vertical? That is if the vertical element is loaded to
resonate at 1/5 of a half wave length what does the ground resistance profile
look like for 120 radials at various lengths of 1/20 wave, 1/10 wave and 1/5 wave?

The question I am really driving at is if mesh is layed down at 100% coverage
about what fraction of a wave length needs to be covered to create a 2.5, 5, and
10 ohm equivalent ground for the vertical above?

In the paragraph above is the mesh simulating a ground or is it fact operating
as a ground.

Thanks,
Dan

wrote:
Has it taken 70 years for the old wives of the FCC to return to Earth,
disregarding B.L & E who forgot to measure ground conductivity, not to
mention permittivity, and think again about economics?

The only stations that the FCC is concerned about is commercial.
And the reason they stick with the standard number is for stability
and getting the max bang for buck, and an easily expected
performance level. Buying a load of wire will beat using more
transmitter power over the long run. If they use 120 radials,
they know they will be getting close to maximum performance.
If they don't, it's a crap shoot. 120 radials *will* outperform
16 of them. There is no question, unless they are over sea
water. I'm not saying hams have to run that many. In fact, I
think 60 will do for most, except the most hard core for good
results. Even less for the more casual user.
But I have no problems with the FCC wanting a certain level
of performance for commercial stations. I have no problems
seeing why they do it either. Wire is cheap compared to
todays level of monthly light bill. With some stations, the radials,
or lack of , in certain directions gives them a controlable
pattern with no surprises in f/s over a period of time
with changing ground conditions. The main thing is
stability of performance over periods of time. Or thats
my take anyway.
MK