"Reg Edwards" wrote in message ...
Incoming radiation angles can be obtained by geometric calculation.
Pythagorus and all that, taking earth curvature, height of ionospheric
layers, number of hops, etc, etc, into account.


Then point your receiving beam into it, if it is adjustable in the vertical
plane. Very non-critical. Antenna apperture angles in the vertical plane
are extremely broad.


The stuff often comes in from more than one angle. Interference between the
different paths causes fading and distortion. An antenna will collect from
all vertical angles regardles of elevation.
----
Reg

===================



Interesting thing happened with the antenna last night.
Had the antenna in the vertical position close to ground ( it is a
truncated co linear dipole) And was prevented from joining the local
group because of multiple QSOs on the same frequency!

Art

Art, KB9MZ wrote:
"And was prevented from joining the local group because of nultiple QSOs
on the same frequency."

Single-element vertical antennas are deficient in directivity at any
azimuth. They have a single null off their tips, that is toward the
zenith.

At HF, groundwave disappears with increasing frequency. Thus, short
range communication is hindered.

Best regards, Richard Harrison, KB5WZI

On 1 Jan 2004 05:57:04 -0800, (Art Unwin KB9MZ)
wrote:

Interesting thing happened with the antenna last night.
Had the antenna in the vertical position close to ground ( it is a
truncated co linear dipole) And was prevented from joining the local
group because of multiple QSOs on the same frequency!

Art

Hi Art,

I'v noted a lot of HF advice to your MF question. Most of it of the
quality of looking under the street lamp for lost keys because that is
where the light is.

No doubt you were "prevented." They couldn't hear you! How is it
your heard them? You used the same polarization they were
transmitting in. Now, these are two significant clues to your
problem(s).

Elsewhere you've offered:
Well I have put my dipole in the vertical position also which negates use of
radials but I have not noticed any profound differences as yet after a few
days !
Another clue (really the same as the two above) which reveals the
problem of so quickly embracing the presumed proof of this "negation."
You negated nothing but opportunity. Your claim is identical to those
CFA's "FCC tested" in Georgia that are 20dB down from their reference.
Your vertical dipole misses only the phasing circuit to qualify for
the Nomenclature gain.

73's
Richard Clark, KB7QHC

Richard Clark wrote in message

No doubt you were "prevented." They couldn't hear you!

I would tend to believe this account. Small vertical antennas next to
the ground with no radials, will be just a tad better than a dummy
load on that band. MK

Mark
I do believe that where the feed point is will make all the difference in
the world. A similar feed point up in the air but feeding colinear verticals
even tho they may be truncated will blow that thought away!
Regards
Art


"Mark Keith" wrote in message
om...
Richard Clark wrote in message

No doubt you were "prevented." They couldn't hear you!

I would tend to believe this account. Small vertical antennas next to
the ground with no radials, will be just a tad better than a dummy
load on that band. MK

" Art Unwin KB9MZ" wrote in message news:9LFJb.49578$I07.153955@attbi_s53...
Mark
I do believe that where the feed point is will make all the difference in
the world. A similar feed point up in the air but feeding colinear verticals
even tho they may be truncated will blow that thought away!
Regards
Art

I doubt it. I use fairly large antennas on that band and still don't
come close to many of the "big strappers" on that band. I've got a
full size inv L, about 45 ft vertical, and also a 42 ft top loaded
vertical. The top loading consists of four 60 ft wires.
Current up the vertical section is nearly constant on that antenna. I
bet that simple antenna will truncate your short collinear verticals
in any direction, and even it's nothing to really get excited about.
MK

Let me clarify this statement so that we are on the same page.
I was hearing several conversations going on the same frequency. Those
conversing obviously were oblivious to other users on the frequency because
of propergation or the peculiarities of my antenna.
I refrained from entering into conversation with the local group because by
joining one group would have caused problems for other groups on the same
frequency.
On reflection it would appear that the horizontal dipole gave low angle TOA
all the way thru 90 degrees.
Thus this is inferior to a vertical that captures the low angles and
descriminates against the high angles plus inferior to a poor vertical that
discriminates against low angles.
This just shows how much ground effect controls the
verticals but only to a much lower extent on horizontally polarised signals
with respect to selectivity.With respect to noise it does not affect me to
much in the comparison because of the use of a Faraday shield.
Regards
Art
"Art Unwin KB9MZ" wrote in message
m...
"Reg Edwards" wrote in message
...
Incoming radiation angles can be obtained by geometric calculation.
Pythagorus and all that, taking earth curvature, height of ionospheric
layers, number of hops, etc, etc, into account.


Then point your receiving beam into it, if it is adjustable in the
vertical
plane. Very non-critical. Antenna apperture angles in the vertical
plane
are extremely broad.


The stuff often comes in from more than one angle. Interference between
the
different paths causes fading and distortion. An antenna will collect
from
all vertical angles regardles of elevation.
----
Reg

===================



Interesting thing happened with the antenna last night.
Had the antenna in the vertical position close to ground ( it is a
truncated co linear dipole) And was prevented from joining the local
group because of multiple QSOs on the same frequency!

Art

" Art Unwin KB9MZ" wrote in message news:acKJb.51720$xX.290427@attbi_s02...
Let me clarify this statement so that we are on the same page.

On reflection it would appear that the horizontal dipole gave low angle TOA
all the way thru 90 degrees.

??? 90 degrees is straight up. NO low horizontal dipole will have very
good low angle performance on that band. Trust me. I used a full size
Z dipole for two years,"01-02" and ended up yanking it down. Good for
close in local stuff. Pitiful for lower angle far off stuff.

Thus this is inferior to a vertical that captures the low angles and
descriminates against the high angles plus inferior to a poor vertical that
discriminates against low angles.

How is it inferior? It's just different. You choose the antenna to
match the path you want to work. If you are going to talk 100-150
miles away, yes a low dipole will work pretty well, maybe the best.
But so will an inv L, or even my top loaded vertical will usually do
fine also. The L will usually be the better of the verticals close if
it's up and down sky wave, as it has more horizontal componant. My
loaded vertical has an overhead null.
Even still, many times, even just 200 miles away, my loaded vertical
is better than the L. Actually, the loaded vertical beats the L
probably 90% of the time. Even fairly close. Farther off paths? The
dipoles I had were poor at best. The vertical is the only way to go in
that case for a simple antenna. Remember, my dipole was at maybe 35-40
ft. Thats like a 80m dipole at 15-20 ft off the ground. Will be poor
for long distance use. Of course, using ground wave, the loaded
vertical is king of the hill here...

This just shows how much ground effect controls the
verticals but only to a much lower extent on horizontally polarised signals
with respect to selectivity.

??
With respect to noise it does not affect me to
much in the comparison because of the use of a Faraday shield.

?? Shield for what? You? MK

Art, KB9MZ wrote:
"Thus this is inferior to a vertical that captures the low angles and
discriminates against the high angles plus inferior to a poor vertical
that discriminates against low angles."

Yes, a vertical discriminates against high angles as it has a null in
its pattern overhead.
What "poor vertical" discriminates against low angles if ground
conductivity is OK? A too-short vertical still has maximum radiation
toward the horizon though it has less than a 1/4-wave or 5/8-wave
vertical antenna has.

Best regards, Richard Harrison, KB5WZI