On Tue, 18 Jul 2006 20:34:32 +0100, "David" nospam@nospam wrote:

If only the vertical is connected, the antenna still radiates although not
as well. If only the
radials are connected, the antenna does not radiate because the radials are
connected to 0V and not a varying voltage.
snip
I notice that two people have simulated the vertical antenna with radials
using EZNEC, and obtained different results. One simulation shows that the
radials radiate, the other shows that they do not.

Hi Dave,

Your statements above show a serious problem with understanding the
operation of antennas.

The radials are not potted plants merely arranged along the ground (or
in the air) to give a sense of symmetry and balance.

You would go further to engage more in dialogue rather than simply
posting statements. Much of the utility of radials has been
discussed, revisited, and rehashed to no apparent effect against what
you offer above. The last sentence is outrageously wrong for any of a
number of reasons (or proof of some pretty stupid simulation).

73's
Richard Clark, KB7QHC

Agreed, the centre junction of the radials is not always at 0V. Current
flows along the coax braid on the inside, meaning that the inside part of
the coax braid and radials junction can be any voltage. The radials have a
voltage gradient along them because of the standing wave. Because the return
current flows on the inside of the coax braid, it is normally safe to touch
or go near the outside of the braid. For permanent low installations in a
public area, coax should be used instead of twin feeder. The fact that the
return current flows on the inside of the braid gives coax its shielding
properties.

On Tue, 18 Jul 2006 21:32:13 +0100, "David" nospam@nospam wrote:

Agreed, the centre junction of the radials is not always at 0V.

Hi David,

In isolation, this statement offers nothing at all, unless, of course,
you are talking about an unexcited system. The notion that 0V
inhabits some greater portion of the antenna, or its radials, or its
junction is a strange concept to its normal operation.

David, AE6EO, has similar concerns that you are presenting what I
would call a naive representation of radiators.

Current
flows along the coax braid on the inside, meaning that the inside part of
the coax braid and radials junction can be any voltage. The radials have a
voltage gradient along them because of the standing wave.

In that sense, 0V does reside at some favored points, but this is not
an explanation of anything.

Because the return
current flows on the inside of the coax braid, it is normally safe to touch
or go near the outside of the braid. For permanent low installations in a
public area, coax should be used instead of twin feeder. The fact that the
return current flows on the inside of the braid gives coax its shielding
properties.

Is this germane to a particular point? Again, these are simply
statements, and they appear unconnected to any kind of dialog.

73's
Richard Clark, KB7QHC