On Apr 18, 5:32*pm, "Dave" wrote:
"Art Unwin" wrote in message

...
On Apr 18, 10:30 am, "Dave" wrote:

I suppose that Gauss has a law that is basic to Maxwells laws but
certainly not his law of statics. That particular law is two dimension
which does not include time.

THE Gauss's law is one of the 4 basic maxwell's equations, and it definately
is 3d.

Great,
So now you know that Maxwell did not use the law of statics and thus
was unaware of the implied connection of the presence of particles
instead of waves.Perhaps now we can leave the subject to rest
Art

Art Unwin wrote:
On Apr 18, 5:32 pm, "Dave" wrote:
"Art Unwin" wrote in message

...
On Apr 18, 10:30 am, "Dave" wrote:

I suppose that Gauss has a law that is basic to Maxwells laws but
certainly not his law of statics. That particular law is two dimension
which does not include time.
THE Gauss's law is one of the 4 basic maxwell's equations, and it definately
is 3d.

Great,
So now you know that Maxwell did not use the law of statics and thus
was unaware of the implied connection of the presence of particles
instead of waves.Perhaps now we can leave the subject to rest
Art

Well Dave, I guess he told you!

This has been hilarious, and you have showed exceptional control.

tom
K0TAR

"Tom Ring" wrote in message
. net...

Well Dave, I guess he told you!

This has been hilarious, and you have showed exceptional control.

i do it just for the humor value, but he is so predictable by now that its
starting to get boring. i think he has run out of laws to break and
formulas to rewrite... once he moved on to the cosmic stuff you could tell
he had run out of new material. thats probably why he went to the more
confined space of the qrz or qth, or whatever that other restricted chat
site was, so he could get a less contentious audience.

On Apr 10, 2:14*pm, Art Unwin wrote:
The coax ground and the reflector is grounded at the same place
at the top of the tower. All horizontal coax is buried.
___________

An r-f ground does not exist at the top of your tower,
or any tower.

Unless some means is provided to prevent r-f current flow
on the outside of the coax and on the tower structure,
they will radiate/receive r-f energy.

This probably accounts for most of the pattern effects
that you didn't expect to have (regardless of the real
pattern that your cone and helix generates).

RF

Richard Fry wrote:
Unless some means is provided to prevent r-f current flow
on the outside of the coax and on the tower structure,
they will radiate/receive r-f energy.

Thus making the vertical antenna longer than 5/8WL.
Using the top of the tower for a ground simply
makes the tower part of the antenna system turning
the entire array into an off-center-fed vertical
dipole with the bottom end grounded. For instance,
a 1/4WL 20m monopole mounted on top of a 60 foot
tower using the tower as the coax shield ground
has a take-off-angle of 57 degrees. The highest
RF current is near the middle of the tower. :-(

To make matters even worse: I had a similar problem
with drooping 1/4WL radials DC insulated from the tower.
The drooping radials coupled RF into the tower and
turned it into a radiator which screwed, oops, I
mean skewed the radiation pattern upwards. It took
me a long time to figure out why my horizontal dipole
was magnitudes better than my 1/4WL vertical on top of
the 1.25WL tall tower which was grounded at the bottom
and floating at the top.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Roy Lewallen wrote:
I measured current, which as everyone with a Novice or higher grade
license should know is the rate of flow of charge(*). The charge flows
in one direction during each half cycle, and in the other during the
other half cycle, resulting in current which is positive for half the
cycle and negative for the other. This is known as "alternating
current". In fact, my measurement system (ferrite core transformers)
will only detect alternating current.

Looking at only one current sample point, one cannot tell
the difference between standing waves and traveling waves.
However, there is a large difference between standing waves
and traveling waves.

If you measure the same current phase at two sample points
that are physically 30 degrees apart, you are dealing with
standing waves.

The equation for a standing wave is of the form:

I = Imax*cos(bz)*cos(wt)

This current is the primary effect on a standing wave
antenna and cannot be used to measure the delay between
points in an antenna because this current does not change
phase relative to length 'z'.

If you measure a 30 degree phase shift in the current
between two sample points that are 30 degrees apart,
you are dealing with traveling waves.

The equation for a traveling wave is of the form:

I = Imax*cos(wt-bz)

This current is a secondary effect on a standing wave
antenna. This is the current that changes phase with
physical length 'z' but is swamped out by the standing
wave.

Roy, you listed three possibilities for people who
read your postings.

1. Those who agree with you and are therefore right.

2. Those who disagree with you and later change their
minds to being right.

3. Those who forever disagree with you and are therefore
forever wrong.

Please consider the 4th possibility.

4. Roy Lewallen is not omniscient and could possibly
be wrong.

Again, would someone please forward this to Roy since
he has plonked me?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

On Apr 19, 8:09*am, Cecil Moore wrote:
Richard Fry wrote:
Unless some means is provided to prevent r-f current flow
on the outside of the coax and on the tower structure,
they will radiate/receive r-f energy.

Thus making the vertical antenna longer than 5/8WL.
Using the top of the tower for a ground simply
makes the tower part of the antenna system turning
the entire array into an off-center-fed vertical
dipole with the bottom end grounded. For instance,
a 1/4WL 20m monopole mounted on top of a 60 foot
tower using the tower as the coax shield ground
has a take-off-angle of 57 degrees. The highest
RF current is near the middle of the tower. :-(

To make matters even worse: I had a similar problem
with drooping 1/4WL radials DC insulated from the tower.
The drooping radials coupled RF into the tower and
turned it into a radiator which screwed, oops, I
mean skewed the radiation pattern upwards. It took
me a long time to figure out why my horizontal dipole
was magnitudes better than my 1/4WL vertical on top of
the 1.25WL tall tower which was grounded at the bottom
and floating at the top.
--
73, Cecil, IEEE, OOTC, *http://www.w5dxp.com

Thank you all for those points raised. I added the ground to the dish
because I was getting a lot of static one night, I have not had any
since but
I need time to compare. The grounding line is a heavy silver coated
braid connected
to each section and to ground. My coax drops to ground and then goes
underground
for a 100 feet or so and grounded again when it resurfaces.
Regards
Art

Art Unwin wrote:
Thank you all for those points raised.

Moral is: There's no such thing as earth "ground"
at 50 feet in the air. There are only ground planes,
counterpoises, and other conductors that become part
of the antenna system. Even the ground wire on an
artificial ground device radiates.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

On Apr 19, 9:13*am, Cecil Moore wrote:
Art Unwin wrote:
Thank you all for those points raised.

Moral is: There's no such thing as earth "ground"
at 50 feet in the air. There are only ground planes,
counterpoises, and other conductors that become part
of the antenna system. Even the ground wire on an
artificial ground device radiates.
--
73, Cecil, IEEE, OOTC, *http://www.w5dxp.com

What if one put a diode in that ground line?

On Apr 19, 8:09*am, Cecil Moore wrote:
To make matters even worse: I had a similar problem
with drooping 1/4WL radials DC insulated from the tower.
The drooping radials coupled RF into the tower and
turned it into a radiator which screwed, oops, I
mean skewed the radiation pattern upwards.
________________

Some designs use drooping radials to reduce the vertical angle of the
peak radiation launched by the monopole section.

But that is a conclusion made for an infinite distance, with
consideration of the propagation environment on the intrinsic pattern
launched by the monopole, and the height of the monopole + its
elevated radials above the earth.

The link below leads to paste-up of NEC screens showing the
performance of a monopole driven against four 1/4-wave, essentially
horizontal radials. The entire system is isolated from earth ground.

The driving impedance, the elevation pattern shape, and the peak gain
are close to "textbook" values for a 1/4-wave monopole driven against
a perfect ground plane.

A form of this design is being used with good success in the AM
broadcast industry -- where using a conventional, buried-radial ground
system is impractical due to rocky terrain.

The groundwave performance of these systems shows that their intrinsic
gain is maximum in the horizontal plane, and very close to the
theoretical value of 5.15 dBi.

http://i62.photobucket.com/albums/h8...dRadials_1.jpg

RF