Szczepan Bialek wrote:
"Jim Lux" wrote
...
Szczepan Bialek wrote:
"K1TTT" wrote
So I look he http://en.wikipedia.org/wiki/Warsaw_radio_mast

"This technique works by applying a DC ground at a point of minimum
radiofrequency voltage, conducting static charge to ground without
diminishing the radio energy. Static electrical charge can build up to
high values, even at times of no thunderstorm activity, when such tall
structures are insulated from ground."

Would be interesting to know the value of the DC current.

Do you agree that it is the field emission (loss of electrons)?
S*

No.. it's plain old corona discharge or triboelectric charging from
particulates

"Static electrical charge can build up to high values".

It take place during transmmiting.
Without grounding do not work.

I simply want to know "the value of the DC current".


Would that be the so-called "fair weather current" about 1 pA/square meter?

Obviously, a big metal tower is going to perturb the local field, so a
tower with a cross section of 1 square meter is going to have a current
a lot bigger than 1pA.

But probably not microamps.

OTOH, a big tower could have substantial capacitance to ground.. I don't
recall off hand what the capacitance of a isolated cylinder is..
I seem to recall that for a rod with lengthdiameter, it's something
like 50pF/meter.

So, a 100 m tower will be 5000 pF.

Say the current is 1000 pA.

In one second, the voltage would be 1E-9/5E-9 = 0.2V

In a minute, 30V
In 10 minutes, 300V..

etc

Probably not enough to charge to voltages quickly enough to be a problem.

Tribocharging from dust and other particulates blowing in the wind is a
LOT faster and a bigger problem.