On Jul 29, 2:03 pm, "John, N9JG" wrote:
http://www.arraysolutions.com/Users/no8d.htm

Impressive...
I suspect the FB is not as clean as one might think....
Still, an impressive exercise...

denny / k8do

Not only impressive but expensive!

"Denny" wrote in message
oups.com...
On Jul 29, 2:03 pm, "John, N9JG" wrote:
http://www.arraysolutions.com/Users/no8d.htm

Impressive...
I suspect the FB is not as clean as one might think....
Still, an impressive exercise...

denny / k8do

On Mon, 30 Jul 2007 04:31:34 -0700, Denny wrote:
On Jul 29, 2:03 pm, "John, N9JG" wrote:
http://www.arraysolutions.com/Users/no8d.htm

Impressive...
I suspect the FB is not as clean as one might think....
Still, an impressive exercise...

I can grasp the "all band" application of a Log Periodic antenna.

Now, explain to me the the theory behind an "all band" phasing system --
one that doesn't use infinite lengths of coax....

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: http://jonz.net/ng.htm

Allodoxaphobia wrote:
On Mon, 30 Jul 2007 04:31:34 -0700, Denny wrote:
On Jul 29, 2:03 pm, "John, N9JG" wrote:
http://www.arraysolutions.com/Users/no8d.htm
Impressive...
I suspect the FB is not as clean as one might think....
Still, an impressive exercise...

I can grasp the "all band" application of a Log Periodic antenna.

Now, explain to me the the theory behind an "all band" phasing system --
one that doesn't use infinite lengths of coax....


Another question (pardon my ignorance)


Is it a given that the TOA that the antenna is "putting out" should be
the same as the incoming angle? Is their no change over time?

Sure is gorgeous, tho'

- 73 de Mike KB3EIA -

Michael Coslo wrote:

Another question (pardon my ignorance)


Is it a given that the TOA that the antenna is "putting out" should be
the same as the incoming angle? Is their no change over time?

An antenna radiates at all elevation angles. It does not "put out" at
any single angle. Likewise, it receives signals from all elevation
angles, not just a single one.

Roy Lewallen, W7EL

In article ,
Roy Lewallen wrote:

An antenna radiates at all elevation angles. It does not "put out" at
any single angle. Likewise, it receives signals from all elevation
angles, not just a single one.

Roy Lewallen, W7EL

Roy, You know better than to make the above "Statement". It is way to
"General" in nature. Certainlky there are a whole raft of "Antennas"
that have both Horozontal and Vertical Beamwidths, that are NOT
Omnidirectional. The OP didn't specify the Frequency at which the
"antenna" was being used at, and the "Higher" the frequency the more
likely the antenna will NOT be OmniDirectional, and will have Horozontal
and Vertical Beamwidths.......

You wrote:
In article ,
Roy Lewallen wrote:

An antenna radiates at all elevation angles. It does not "put out" at
any single angle. Likewise, it receives signals from all elevation
angles, not just a single one.

Roy Lewallen, W7EL

Roy, You know better than to make the above "Statement". It is way to
"General" in nature. Certainlky there are a whole raft of "Antennas"
that have both Horozontal and Vertical Beamwidths, that are NOT
Omnidirectional. The OP didn't specify the Frequency at which the
"antenna" was being used at, and the "Higher" the frequency the more
likely the antenna will NOT be OmniDirectional, and will have Horozontal
and Vertical Beamwidths.......


I tend to agree with Roy. Omni or not, Every antenna radiates in every
direction. Maybe not as much in one as the other, but radiate they do.

So many folks look at the Take off angle as some sort of blob that
leaps off the antenna at a particular angle, and if it isn't at that
"correct" angle, then heaven help you i you are trying to operate NVIS
or DX or whatever.

Some time back, at Roy's suggestion, I conducted some experiments with
my dipole and vertical antennas to see which one "worked best". Using a
attenuation pad, it really wasn't as trivial as I thought it would be.
But I learned a lot. Dipole at the time was an OCF, and vertical was a
Butternut HF6V.

What I did learn was that at any given moment, either the vertical or
the horizontal antenna was "the best". While some generalizations could
be made for distance and the angle the signal was likely coming in at,
there was a lot of variation within it. The difference could vary over
time also.

That being the case, I questioned if assuming that the angle for best
reception is also the angle for best transmission, especially with what
appears to be a change over time.

- 73 de Mike KB3EIA -

On Tue, 31 Jul 2007 15:45:19 -0400, Michael Coslo
wrote:

I tend to agree with Roy. Omni or not, Every antenna radiates in every
direction. Maybe not as much in one as the other, but radiate they do.

So many folks look at the Take off angle as some sort of blob that
leaps off the antenna at a particular angle, and if it isn't at that
"correct" angle, then heaven help you i you are trying to operate NVIS
or DX or whatever.

Hi Mike,

Another metaphor would be Craps shooting. The distribution of
separate outcomes is each 1 in 36, but there are a preponderance of 7s
over time with very much higher probability. To ignore the
preponderance (this blob) to the observation of single rolls would
have left the design of antennas stuck in the age of Marconi.

That being the case, I questioned if assuming that the angle for best
reception is also the angle for best transmission, especially with what
appears to be a change over time.

Reciprocity is another one of those rules revealed by the
preponderance of outcomes - and so often decried as impossible through
single reports of failure.

However, returning to the original link, and the design behind it, it
is called beam forming as practiced through controlled delays. If the
math reveals that a signal is peaked with one particular setting of a
combination of delays, and if that combination reveals an apparent
source coming in from a particular angle; then we can say that yes,
Virginia, there is a take off angle. We can reasonably expect that
calling back through the same combination of delays through to those
various antennas will result in a more optimum link.

That, or through this design, you can adjust to obtain that optimum
(which will more than likely reveal another take off angle). You will
then be able to ponder why they come in best at one angle while you go
out best at another. Yes, a distinct possibility that becomes more
distinct through this control, and the resolution of take off angles.

Now, as to the matter of this "some sort of blob that leaps off the
antenna." Modeling propagation will reveal if you define a circuit
(the point of origination and the intended audience's location), and
you chip in the general antenna radiation lobe characteristic; then at
significant distances a matter of one degree can be resolved. For
sharply lobed antennas (and this 6 bay is quickly approaching that),
the roll-off response and a one degree shift can plunge the listener
into deafness. Of course, the vagaries of propagation can easily
upset the apple cart - but again, this sharply reveals how "some sort
of blob" has become distinctly important compared to the gross
distribution of possibilities.

73's
Richard Clark, KB7QHC

On Jul 31, 2:45 pm, Michael Coslo wrote:


What I did learn was that at any given moment, either the vertical or
the horizontal antenna was "the best". While some generalizations could
be made for distance and the angle the signal was likely coming in at,
there was a lot of variation within it. The difference could vary over
time also.

I did the same thing at one time on 40m. "Compared a 1/4 WL ground
plane vs a horizontal dipole. You see some strange things at times.
The distance of the path has a large bearing over which is best.
In my case, 800 miles seemed to be about the crossover point
where both would be about the same on peaks. But even then,
sometimes you will see peaks on the vertical that are the strongest.
The ionosphere seems to tumble back and forth.
On the longer paths at say 1500 miles, the peaks on the vertical
would
almost always be the strongest. And the farther the distance out,
the
larger the difference would be. IE: the vertical would be 2 S units
better
vs the dipole to CA. This was very repeatable, and almost the same
margin
on any given night. To VK, the difference would be 4 S units.. Again,
that
same margin most any night.
As you can see, I'm a believer in a good vertical for the lower bands.
The only thing that could beat it were either yagi's, or multi element
arrays like the various curtains, etc.. Other than that, I smoked
everyone
else on the band to DX.. I did run a KW though.. :/ I would be 20
over 9
in Tokyo...
The bobtail curtains could put a hurt on me though...
But, they had three elements, vs my one..
I almost always used receive as the indication as to which was best
at a given time. I could probably count the number of times
reciprical
operation didn't pan out on a single hand, and have a few fingers
left..
It's pretty rare not to be reciprical receive vs transmit.. IE: almost
never happens, except in a really weird situations.


That being the case, I questioned if assuming that the angle for best
reception is also the angle for best transmission, especially with what
appears to be a change over time.

I think it's quite accurate.. I use my switch and compare.. Whichever
receives the best signal gets the nod as far as transmit.
BTW, my vertical was pretty good compared to many you see...
Was full sized, with the base at 36 ft with sloping radials. Not much
loss involved compared to some you see on the ground with a
few meager radials.. It was a lot better than the 1/4 wave I had
ground mounted with 32 radials.
It would always seem just as "hot" as my dipole on receive. It was
just vertical. So it's quite possible for a lesser vertical not to see
the
results I had. As an example, the ground mount with 32 radials
was barely better than the dipole to CA. You didn't see the 2 S unit
difference as on the elevated GP I used later. So in the case of
the ground mount, the distance where it would overtake the
horizontal antenna on peaks would be farther out, vs the GP.
MK