Dave wrote:
...

Dave:

Krist! Turn off the 60 hz receiver you silly duck! That right hand
rotation is, most likely, making you dizzy!

JS

Deni F5VJC wrote:
I have recently been plagued by rain static on a new vertical antenna,
this a 42 foot vertical fed at the base through an SG230 auto tuner,
and used on all bands. It seems I need a static bleed of some sort, a
choke or resistor. What is the best component to use in an outdoor
environment?

Take a look at page 4 of the schematic. There is already
a static bleed through 20 turns on a transformer winding
to ground plus about 40K ohms of resistance to ground. You
are already bleeding the static charge, just not fast enough
to get rid of the RF content. The problem is that the
RF content of the precipitation static is finding its
way through your receiver along with the desirable RF
signals. Question is: Is there something that discriminates
against local RF static without discriminating against
desirable RF signals?

Here's my two cents and others certainly do vehemently
disagree with me.

A single precipitation static charge transfer is at a
localized point. Desirable arriving RF waves/photons are
spread out over the entire antenna. That should make them
separable.

Folding the antenna into a loop is one way to reduce
precipitation static. Desirable arriving RF waves are
unaffected by folding as they encounter the entire antenna,
i.e. it's hard to tell the difference between the
performance of a dipole and a folded dipole.

Single charges of precipitation static, however, are
confined to one point on the antenna. If there is a discharge
path to the other side besides through the receiver, the
charge will at least partially take the shortest path of
reduced resistance. IMO, that's why folded antennas are
quieter than open-ended antennas as far as precipitation
static is concerned.

The way I reduced the problem with open-ended antennas is
to use heavily insulated wire. Bare conductors transfer
all charges. 600 volt insulation blocks charge transfer. In
my experience, 1000v insulation blocks most charge transfer.
I use something called "Quietflex" that has 1000v insulation.
Most of the precipitation static doesn't transfer to
the antenna wire while RF waves/photons flow right
through the insulation with little attenuation. I suspect
plastic encased antennas are quieter than bare antennas.

There is a wealth of information on precipitation static
on the web, a lot of it having to do with antennas on
airplanes. Folding and insulating are two ways they have
solved the problem.

Folding or insulating your vertical may or may not be
feasible. If you solve your problem, please share it with
us here.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
600 volt insulation blocks charge transfer.

Lest I be nibbled to death by a flock of angry geese,
this should be, "600 volt insulation blocks *some*
charge transfer." Leaving out the word "some" was
a typo.
--
73, Cecil http://www.w5dxp.com

On Dec 9, 1:57 pm, Cecil Moore wrote:
Cecil Moore wrote:
600 volt insulation blocks charge transfer.Lest I be nibbled to death by a flock of angry geese,
this should be, "600 volt insulation blocks *some*
charge transfer." Leaving out the word "some" was
a typo.
--
73, Cecil http://www.w5dxp.com

Interesting Cecil, my vertical antenna is constucted from a 42 foot
length of coaxial cable using the outer braid as the radiator (but the
inner and outer are shorted together anyway) and this fat vertical
"wire" is suspended inside a telescopic fibre glass pole from
Spiderbeam ( not the conductive type). So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.
73, Deni
F5VJC

Deni F5VJC wrote:
So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.

Is anything about your antenna in contact with charged
rain? Your noise problem might have the same cause
as lightning, i.e. the global atmospheric electrical
circuit. You might be experiencing simple corona
discharge.
--
73, Cecil http://www.w5dxp.com

Cecil, can you state that if an antenna is in the house one would not
hear static?
I seem to remember that when I was at the top of a mountain in a rain
forest I put the antenna inside the car but the noise was S9 plus....
no communication could get thru
Bearing this in mind static noise was radiated to the antenna was it
not? So why cannot a droplet falling at 32 ft per sec sq not produce
radiation or if it impacts a dielectric transfer a electric charge with
curl? Isnt this lightning on a small scale? What I am getting at I
suppose
is if the antenna is protected from the environment and gets static
noise surely it is a radiaated phenomina. IR antennas have never stated
that their antenna was immune to static!


Cecil Moore wrote:
Deni F5VJC wrote:
So, I guess my verical wire is
quite well insulated and certainly not in contact with charged rain.
We've had particularly heavy rainstorms lately in France and this is
definitely rain or rain induced static., starting and stopping in
sympathy with the rain storms very easy to identify.

Is anything about your antenna in contact with charged
rain? Your noise problem might have the same cause
as lightning, i.e. the global atmospheric electrical
circuit. You might be experiencing simple corona
discharge.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

The way I reduced the problem with open-ended antennas is
to use heavily insulated wire. Bare conductors transfer
all charges. 600 volt insulation blocks charge transfer. In
my experience, 1000v insulation blocks most charge transfer.

Your radio doesn't actually hear clear down to DC, does it? :-)

The effect is heard as a result of the charge striking the antenna,
thus changing the charge on the antenna. As you know, for a given
capacitance, a 600 volt dielectric couples charge just as well as a
1000 volt dielectric. In such a case the 'pop' is capacitively
coupled broadband noise. But whether the antenna is insulated or not,
looped or not, the static noise is due to a rapid (albeit small)
change in charge on the antenna being coupled by some means into the
receiver.

I use something called "Quietflex" that has 1000v insulation.
Most of the precipitation static doesn't transfer to
the antenna wire while RF waves/photons flow right
through the insulation with little attenuation. I suspect
plastic encased antennas are quieter than bare antennas.

Maybe. It would make sense that the amount of static noise coupled
from the environment would be proportional to the coupling
capacitance. Knowing that charge tends to gather on a surface, the
thicker the 'dielectric', the lower the capacitance. A small series
capacitor in most circuits would tend to differentiate an impulse,
producing a signal which is proportional to the slope of the impulse.
With larger values of capacitance the coupled signals tend to follow
the input. So although it's not likely that insulation would reduce
the number of noise 'events', it is possible that it would narrow the
resulting broadband power spectrum. This could be helpful, as long as
it narrows it in the part of the spectrum you happen to be using. ;-)

73, ac6xg

Jim Kelley wrote:
Your radio doesn't actually hear clear down to DC, does it? :-)

Doesn't matter since I can't hear DC anyway. If the
charge striking the antenna is a DC pulse, part of
the released energy extends into the RF region whether
the event is linear or not.

The effect is heard as a result of the charge striking the antenna, thus
changing the charge on the antenna. As you know, for a given
capacitance, a 600 volt dielectric couples charge just as well as a 1000
volt dielectric. In such a case the 'pop' is capacitively coupled
broadband noise. But whether the antenna is insulated or not, looped or
not, the static noise is due to a rapid (albeit small) change in charge
on the antenna being coupled by some means into the receiver.

Your idea assumes linear displacement current, i.e.
charge transfer around the dielectric. My idea assumes
charge transfer through the dielectric, i.e. a tiny
nonlinear breakdown of the dielectric. We can haggle
over the exact physical mechanism but the result is
probably the same in either case and maybe a combination
of the two. The thicker the dielectric coating on the
antenna wire, the lower the precipitation noise from the
antenna. That has been proved to be true for airplane
antennas moving through air. Seems relativity would hold
true for air moving past antennas.

It would make sense that the amount of static noise coupled from
the environment would be proportional to the coupling capacitance.
Knowing that charge tends to gather on a surface, the thicker the
'dielectric', the lower the capacitance.

It would also make sense to say the thicker the dielectric,
the smaller is the chance of a nonlinear event. I sure wish
I had not kissed my girlfriend on her ear ring 50 years ago
after sliding across plastic seatcovers wearing wool pants.

So is precipitation static a linear or nonlinear event? Or
a combination of the two? Does it matter?
--
73, Cecil http://www.w5dxp.com

Cecil, you don't have to postulate a non linear breakdown within the
dielectric to explain the transfer of energy from the charged particle
striking the surface of the insulation to the free electrons on the
wire... Capacitance will handle that nicely... As you stated, a
thicker insulator makes a quieter antenna under static conditions...
Capacity effect would seem to answer that...
If you don't like that, a charged particle striking the dielectric
surface suffers an abrupt change in motion... A charge changing motion
has it's own method of talking to us...
And, lastly, we have not roundly beaten the water droplet for dripping
off the antenna and taking a charge with it...
"Bartenner, I'll have one, hic, for the road."...
denny / k8do

Deni F5VJC wrote:
...
Any thoughts, how have you solved this?

73, Deni

F5VJC


Deni:

Perhaps a very high resistance hooked to the radiator and gnd would be
the quick, cheap fix?

Regards,
JS