cloth?: dipole coiley?
 

On Tue, 09 Jan 2007 13:12:58 -0800, Roy Lewallen
wrote:

Richard Harrison wrote:
John Ferrell wrote:
"The effects seem to be accumulative to some of us."

Perhaps. Intensity, proximity, and radiated frequency are important in
my experience.
. . .

Sure enough, I've got indisputable proof. The longer I'm a ham, the
dimmer my eyesight and hearing, the shakier my hand, the unsteadier my
gait. I can't remember things as well as I used to. And I'm even growing
more hair out of my ears!

Watch out, this stuff is dangerous in the long haul!

Roy Lewallen, W7EL

Yea, me too Roy. Bun unlike you I hot jumped Loran transmitting
towers. And for those not aware the transmitting power was one
mega-watt. On a damp day you sure could draw a heck of an arc when you
jumped off.

Danny, K6MHE

cloth?: dipole coiley?
 

Roy Lewallen wrote in
:

Richard Harrison wrote:
John Ferrell wrote:
"The effects seem to be accumulative to some of us."

Perhaps. Intensity, proximity, and radiated frequency are important
in my experience.
. . .

Sure enough, I've got indisputable proof. The longer I'm a ham, the
dimmer my eyesight and hearing, the shakier my hand, the unsteadier my
gait. I can't remember things as well as I used to. And I'm even
growing more hair out of my ears!

Watch out, this stuff is dangerous in the long haul!

Epidemiological studies often provide "indisputable proof" to people
looking for support for their "beliefs". For instance, if they don't
want a mobile phone tower in their visual environment, then the results
of such studies are elevated to "indisputable proof" to oppose such
structures.

The illogical thing is that there is more opposition to taller towers,
though they are safer from an EMR perspective (both in terms of the
radiation from the tower, and the power radiated by mobiles to
communicate with the tower). That indicates to me that EMR safety is not
uppermost in their minds, and their concern is a misrepresentation.

Thing is, when you depend on epidemiological studies, while you can
create a lot of FUD (fear, uncertainty and doubt), you can't really
prove anything safe.

Owen

cloth?: dipole coiley?
 

In the U.S., unfortunately, "proof" that something has caused harm means
convincing a jury consisting of people who, on the average, probably
couldn't find Japan on a map and around half of whom don't believe in
evolution.

Roy Lewallen, W7EL

Owen Duffy wrote:

Epidemiological studies often provide "indisputable proof" to people
looking for support for their "beliefs". For instance, if they don't
want a mobile phone tower in their visual environment, then the results
of such studies are elevated to "indisputable proof" to oppose such
structures.

The illogical thing is that there is more opposition to taller towers,
though they are safer from an EMR perspective (both in terms of the
radiation from the tower, and the power radiated by mobiles to
communicate with the tower). That indicates to me that EMR safety is not
uppermost in their minds, and their concern is a misrepresentation.

Thing is, when you depend on epidemiological studies, while you can
create a lot of FUD (fear, uncertainty and doubt), you can't really
prove anything safe.

Owen

cloth?: dipole coiley?
 

Roy Lewallen wrote:
In the U.S., unfortunately, "proof" that something has caused harm means
convincing a jury consisting of people who, on the average, probably
couldn't find Japan on a map and around half of whom don't believe in
evolution.


So thats why I didn't get pick the last time I was called for jury
duty!!! I could locate Japan! ;^)

- 73 de Mike KB3EIA -

cloth?: dipole coiley?
 

Is aluminium (baking) foil any good as a ground plane? How does it compare
to metal mesh?

cloth?: dipole coiley?
 

The short answer is that it would be very good at VHF and above, and
poorer at lower frequencies. How it would compare with a metal mesh
depends on the frequency, the nature of the mesh, and the application,
so there's no simple answer to the comparison question.

To make it reasonably opaque to currents and fields, it needs to be at
least several skin depths thick. As far as I've been able to tell,
aluminum foil is roughly 0.02 mm thick. That would be 3 skin depths at
about 150 MHz; below that frequency, it would be increasingly
transparent. Above that frequency, it would have the same resistance as
a group of separated wires having the same surface area. Because it has
such a large surface area, I'd expect it to do as well as or better than
most wire meshes down into the HF range. But as I said earlier, it depends.

Roy Lewallen, W7EL

David wrote:
Is aluminium (baking) foil any good as a ground plane? How does it compare
to metal mesh?