" wrote in message
news:_IrSd.38654$tl3.18012@attbi_s02...

"Jerry Martes" wrote in message
news:XJqSd.17298$uc.14470@trnddc01...



" wrote in
message news5bSd.33636$tl3.9146@attbi_s02...
Regarding antenners, thats right,antennas.
Plenty of listings for various gains achieved with antennas
but I have not seen any similar listings for F/R and F/B.
Is there any around so I can see what can be or has been attained or
is blocking of rear signals of little consequence for todays hams. I can
see that being true
for when the band has just opened and propagation has not opened to the
rear or
with net operations so perhaps gain is every thing after all.
It is my opinion that if interest/efforts are increased first in
deflecting the rear action to the
front first and thereby INCREASING the front lobe width there will be
more opportunities
for increasing gains without the side lobes and narrow forward lobes
that accompany Yagi's.
as well as shorter booms. ( more deflectors/reflectors perhaps)
( no religeous, porno or genocide preaching please, fighting to see
which is best
could take place on boat anchor nets to see which has taken position of
the lowest level)
Regards
Art


Art

Excuse me if I misunderstand your post above. It reads to me that you
have an interest in building an antenna that minimizes "side lobes" to
the rear of the main beam.

Correct..minimise or remove
.
In my experience with directional antennas I have not been able to
corelate minimum side lobes with maximum gain.

Oh I fully agree with that observation and that is another part of my
thinking
as it should never be so UNLESS you are captive to Yagi thinking.

I'd suggest that the sidelobes will probably never be held lower than
the same level as the forward gain. That is a 20 db gain antenna will
have side lobes no lower than - 20 db with respect to the main lobe.


20 db gain would not be rotatable at HF which represents a huge drawback,
better to stay with a rombic thinking and cancel the energy complely to
the rear of the
feed point.

Again that is true if you are captive to the Yagi
Make no mistake the Yagi is as about as simple a thing to make that works
well,
it is doubtfull with respect to simplicity it can be beat.

Or, another
way to put it is; there will always be a side lobe that gets up to or
above isotropic level somewhere in the pattern.

Then think what actualy generates a lobe whether directional(frontal)
or at the rear.



I think I'm misreading your post because I read it to say that main lobe
could be increased in width while increasing the antenna sensitivity.
That doesnt make sense, so I guess I'm not understanding.

Yes you misunderstood. Bank to the ballon if all the volume to the rear
of the figure 8 ahat the new diameternd placed in the front of the feed
point it is obvious will be wider and with more gain and if I might adde
NO sidelob.
You have to return to basics to understand that it is energy to the rear
that
generates side lobes at the rear.


And, I submit that, with yagis, there is so little energy radiated in
the sidelobes of a 15 db gain Yagi antenna that *all* the sidelobe
radiation redirrected to be included in the main lobe wont add
significantly to the Practical Useability of the antenna. I write
Practical Useability because I want to distinguish that from scientific
exploration of antenna gain, which accounts for fractions of one db.

Well that is the essence of my disagreement with the masses which I admit
I have not yet released my findings. Think about it, I could have a single
directive lobe
that has twice the energy of a standard dipole in unidirectional form
and with a broader lobe.and I have yet to discuss yagi type manipulations
that
narrow the lobe ,which can be unhelpful, and start from a new datum line
if one
wants to determine gain per unit length type thinking that goes with
Yagi,s.
.Maybe some experts can add some view points, after all it is a general
discussion group on antennas where many believe all is already known
and in a book....... grin
Regards
Art ........KB9MZ

Jerry

Art

You obviously understand antenna patterns, I have a little professional
experience with antenna design. But, I am an old guy who wouldnt even
qualify as an antenna engineer by today's standards. So, I have very litle
to add to your threories on antenna pattern shaping.
I would suggest to you that all antena pattern terminology uses the
pattern width to identify gain (or dirrectivity). So, to be consistant,
higher gain antenna patterns will produce a narrower main beam angle.
Again, I dont suspect that you dispute the validity of my statement on
pattern width. I do suspect I am (again) misunderstanding.

Jerry

" bravely wrote to "All" (21 Feb 05 19:20:16)
--- on the heady topic of " F to B and F to rear"

How about stuffing a dielectric type material between the elements so
that the antenna can be made a lot shorter though it still remains
electrically resonnant? How about making antennas 3 dimensional
instead of on a single plane? How about using newly discovered
materials exploiting their strange new properties.?

I don't mean to upset any apple carts but this stuff has been done for
almost 200 years and no really new ideas have been introduced since
the past half century.

A*s*i*m*o*v


au From: "
au Xref: aeinews rec.radio.amateur.antenna:5555

au The idea of 'reflectors' is perhaps the wrong approach, I prefer the
au term deflectors
au as one sees when rays hit a knife edge. Also close coupling enables
au elements to
au be current heavy and others voltage heavy such that it would appear
au that a element was doing nothing when in fact it is the link for more
au current loaded elements
au in cluster form. A wall that you suggest can indeed reflect and absorb
au radio waves but a
au wall is beyond my means thus resonance remains a important function of
au change.
au But then close coupling of elements together with the deflection
au aproach has been
au dissed many times over the years with me and always ends in derision
au of the author
au Time will tell but experimentation can be enjoyable especially when a
au trail of past results
au suggests that my rubicon is at hand and close to submission to RADCOM
au where experimentation is still valued.

au Heh, no politics here or religeon so all can join in without fear
au especially those who are willing
au to consider and pursue 'outside of the box' ideas that others
au distain., in order to gain better
au understanding
au Regards
au Art


au "Buck" wrote in message
au ...
On Mon, 21 Feb 2005 17:10:00 GMT, "
wrote:

Roy allow me to be a bit more directive regarding my pursuit.
I am trying to see what methods that can be used for maximum gain.
Having made many a long boom yagi 80 feet and 13 elements I have
come to the cinclusion that thinking must move away from Yagi's.
If one starts with a balloon squeezed in the center we get the figure 8
pattern.
I think we all can agree on that
My logic is that we must find a way to move all the volume at the rear to
the front thus increasing
the front diameter before we begin to massage it. The present thinking is
one sqeeze at the rear
is the best that one can do. It is here that I part company with the norm.
If we move all the volume to the front then talk of gain/boom length
becomes
moot.

.... Acme Corp: Unlimited credit for disadvantaged coyotes.

Asimov
That's right, because every thing is known about antennas
And when something new comes along many will say they knew that all
the time
Art



"Asimov" wrote in message
...
" bravely wrote to "All" (21 Feb 05 19:20:16)
--- on the heady topic of " F to B and F to rear"

How about stuffing a dielectric type material between the elements so
that the antenna can be made a lot shorter though it still remains
electrically resonnant? How about making antennas 3 dimensional
instead of on a single plane? How about using newly discovered
materials exploiting their strange new properties.?

I don't mean to upset any apple carts but this stuff has been done for
almost 200 years and no really new ideas have been introduced since
the past half century.

A*s*i*m*o*v


au From: "
au Xref: aeinews rec.radio.amateur.antenna:5555

au The idea of 'reflectors' is perhaps the wrong approach, I prefer the
au term deflectors
au as one sees when rays hit a knife edge. Also close coupling enables
au elements to
au be current heavy and others voltage heavy such that it would appear
au that a element was doing nothing when in fact it is the link for more
au current loaded elements
au in cluster form. A wall that you suggest can indeed reflect and absorb
au radio waves but a
au wall is beyond my means thus resonance remains a important function of
au change.
au But then close coupling of elements together with the deflection
au aproach has been
au dissed many times over the years with me and always ends in derision
au of the author
au Time will tell but experimentation can be enjoyable especially when a
au trail of past results
au suggests that my rubicon is at hand and close to submission to RADCOM
au where experimentation is still valued.

au Heh, no politics here or religeon so all can join in without fear
au especially those who are willing
au to consider and pursue 'outside of the box' ideas that others
au distain., in order to gain better
au understanding
au Regards
au Art


au "Buck" wrote in message
au ...
On Mon, 21 Feb 2005 17:10:00 GMT, "
wrote:

Roy allow me to be a bit more directive regarding my pursuit.
I am trying to see what methods that can be used for maximum gain.
Having made many a long boom yagi 80 feet and 13 elements I have
come to the cinclusion that thinking must move away from Yagi's.
If one starts with a balloon squeezed in the center we get the figure 8
pattern.
I think we all can agree on that
My logic is that we must find a way to move all the volume at the rear to
the front thus increasing
the front diameter before we begin to massage it. The present thinking is
one sqeeze at the rear
is the best that one can do. It is here that I part company with the
norm.
If we move all the volume to the front then talk of gain/boom length
becomes
moot.

.... Acme Corp: Unlimited credit for disadvantaged coyotes.