On 27 feb, 02:18, (Rick) wrote:
Is there any danger that the ends of my verticals radials could set the leaves
in the woods afire? There's high voltage there at the ends, right?

Rick K2XT

Hello Rick,

It will depends on the power, when it is up to several hundreds watts,
I think it is not likely.

Probably you will use about 3 or more radials, so the current and
hence the voltage at the end will not be as high as in the vertical
radiator. The strong E-field very close to the ends will generate
heat in fresh wood/leaves. However before the material will become
flammable, the water has to evaporate. When the water contents
decreases, the loss factor will decrease also. Because of this, the
heat generation per volume will decrease also.

Other issue is corona breakdown directly to foliage. Highest voltage
at the ends will be in case of quarter wave and 5/8 antenna. A Halve
wave will induce significant lower current into the radial system (and
hence lower voltage at the ends).

You might do an experiment and point the material in question towards
the end of the radials (parallel with the E-field lines and grounded).
Take some distance, turn on maximum power and afterwards (power of)
check for temperature rise. This may also show possible effects of
corona breakdown from the radial wire(s) to the material under test.

Best Regards.

Wim
PA3DJS.