Stagnating antenna designs
Art Unwin KB9MZ
you would
be hard put to shell out some money if you already had a previous
edition that had some age on it when the only real addition is the
move to computor designs. Not sure whether this is because elmers are
fading with the hobby or new designs are not pursued because of
harrasment as with the E/H antenna?
My particular beef is that books still concentrate on trapped dipoles,
transmission line lengths, stubs e.t.c without reviewing old designs
to see if advantages can be obtained by substituting 'loop' design
additions for these 'old style' antennas such as the Zepp , G5RV,
dipole. e.t.c.
If the idea has merit, discussed and added to the present day books we
could see
the older antennas in a different light instead of adding traps or
multiple transmission lines for multi banding, ala Cecil,s
contribution with his antenna page.( sticking with the multi resonant
transmission line aproach.)
As most of the 'old' wire designs use a transmission line to aid in
the phasing of an antenna so that gains from collinear designs can be
realised, it would appear to me that replacing traps,stubs, specific
transmission line lengths with a loop antenna addition would be more
user friendly, whether it is used for a fixed frequency or a multi
frequency antenna or even a trapped dipole antenna
Since many of the contributors to antenna articles are members of
this group
perhaps some could explain this ommision whether it is because of lack
of merit or because as a group we are more intent expressing the
disadvantages
of anything different that comes on the scene except those that are
already written about in a book that can give one some courage ?
To give a better idea of what I am talking about one should look at
the standard
dipole with a variable frequency loop antenna at it's center,versus
say a Zepp style antenna,trapped dipole, or a G5RV of which many speak
of with a disapointing tone.
Comments are appreciated /welcome, even tho responses follow the
prevailing rule of focussing on the negative aspects as opposed to
possible advantages.
Art
( A Brit from East London Roy ! )
Richard Clark
>To give a better idea of what I am talking about one should look at
>the standard
>dipole with a variable frequency loop antenna at it's center,versus
>say a Zepp style antenna,trapped dipole, or a G5RV of which many speak
>of with a disapointing tone.
Hi Art,
To give a better idea it might help to know what you mean by a
standard dipole which you then pair up with
> Zepp style antenna,trapped dipole, or a G5RV
which immediately obscures what you are talking about with a
contradiction. Further, the editorialization:
>a G5RV of which many speak
>of with a disapointing tone.
is not true. I doubt you could even name a few, much less many.
When we peel away this bric-a-brac we are left with
>dipole with a variable frequency loop antenna at it's center
with a presentation that it is somehow better than the simple dipole
we started with. You might want to explain why, much less exactly
what you mean by
>variable frequency loop antenna
73's
Richard Clark, KB7QHC
Richard Harrison
If one looks at present day antenna books such as the ARRL offerings you
edition---."
Antennas have been developing for a century. The principles don`t change
much and are known. ARRL has new hams for which the old information is
new. The old books can be refined and if there is worthwhile new
information it is likely added. The complaint that there isn`t anything
new may be misdirected as ARRL is reporting the scene, not making the
news. ARRL`s books should be compared with other available books on
antennas. I think ARRL has done well considering what it has to work
with.
Best regards, Richard Harrison, KB5WZI
Fractenna
>much and are known. ARRL has new hams for which the old information is
>new. The old books can be refined and if there is worthwhile new
>information it is likely added. The complaint that there isn`t anything
>new may be misdirected as ARRL is reporting the scene, not making the
>news. ARRL`s books should be compared with other available books on
>antennas. I think ARRL has done well considering what it has to work
>with.
>
>Best regards, Richard Harrison, KB5WZI
>
Hi Richard,
I hear denial, perhaps unintentional.
The perception that antennas are, well, an old and hoary field is clearly wrong
in the face of developments, still happenng.
A compelling case for this is with fractal antennas. Of course, one may easily
argue that such designs are not really a part of the amateur community, a
viable statement. This despite some concrete efforts to inform the community as
a whole, and leadership--level acceptance and confirmation of the approach by
the professional antenna community (see, for example, the Feb 2002 IEEE AP
Magazine review article by Yaya Ramhat-Samii and his student, which affirms and
confirms the findings of my research team's efforts (in particular)).
Nor are they likely to be part of the amateur community, given the sentiment
Art has articulated so clearly. Thus we have a strange situation where in the
next two or three years, amateurs use G5RV's and screwdriver antennas, while
the wireless devices around them use, well, something else. It is happening: I
know.
The interesting issue is which will survive:-- amateurs or fractal antennas? I
don't mean that in some spiteful way, but I fear for our great hobby and use
this as an example of the great disconnect we have technically these days.
IMHO, the direction we need to go is not in some technical growth--its too late
for that-- but towards preparedness for emergency communication and monitoring.
We are very good listeners:-)
We need the OO program again.
73,
Chip N1IR
Reg Edwards
Whether we like it or not, books and other paper products are slowly but
inexorably being replaced by computer software.
Regurgitation of old books and articles by unimaginative introspective
plagiarists is no longer a useful occupation. Armchair readers become bored.
To the older readers there remains sentimental and historical interest.
Once the computer is involved the whole attitude to 'knowledge' changes. The
ways in which knowledge is used are controlled by the means of conveying it.
My RadCom arrives regularly every month. Most months it ends up unwrapped in
the waste bin.
Amateur Radio either has to change with the times or become an infrequently
visited museum exhibit. Just as the up-down telegraphy key has become.
Peculiarly enough, after 15,000 years the Wheel is still with us - it is
Legs which are becoming redundant.
---
Reg, G4FGQ
Art Unwin KB9MZ
Hi Richard, thanks foryour comments.
LEt me respond by getting at the nitty gritty.
A variable frequency antenna is an antenna fashioned in the form of a
loop
which with the addition of a capacitor resonates at a particular
frequency.
Reg has kindly supplied some computor programs that show by remotely
varing the value of this capacitor you are able to make the loop into
a multi frequency antenna. Hopefully so far so good .
If one has a dipole where inbetween the feed points a loop with a
variable capacitor is inserted we then have a collinear antenna for
frequences in the same range as the original loop antenna if the
dipoles were built to 20 metre lengths.
Now compare this with say a zepp which works at a fixed frequency by
the use of a stub. I'll leave it to you to compare both designs to see
if there are advantages obtained to save clutter on my part .
'Doc
Fracky,
Check the newest edition of the ARRL's Handbook,
fractal antennas are listed under the sections on
dummy loads and insulators.
'Doc
Richard Clark
> If one has a dipole where inbetween the feed points a loop with a
>variable capacitor is inserted we then have a collinear antenna for
>frequences in the same range as the original loop antenna if the
>dipoles were built to 20 metre lengths.
Hi Art,
This is difficult to follow. I can only guess you have described a
remotely tuned gamma loop match to an opportunistic radiator.
Sylvan Butler
> To the older readers there remains sentimental and historical interest.
> Peculiarly enough, after 15,000 years the Wheel is still with us - it is
> Legs which are becoming redundant.
I find myself quite sentimental re. Legs. :)
sdb
--
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| Watch out for my e-mail address. Thank UCE. >>>> change ^ to @ <<<< |
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safety deserve neither liberty nor safety. --Benjamin Franklin, 1759
Stop Senator Fritz Hollings-S2048, Palladium, and TCPA, NOW!
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Mark Keith
>
> I hear denial, perhaps unintentional.
>
> The perception that antennas are, well, an old and hoary field is clearly wrong
> in the face of developments, still happenng.
Oh Really?
>
> A compelling case for this is with fractal antennas. Of course, one may easily
> argue that such designs are not really a part of the amateur community, a
> viable statement. This despite some concrete efforts to inform the community as
> a whole, and leadership--level acceptance and confirmation of the approach by
> the professional antenna community (see, for example, the Feb 2002 IEEE AP
> Magazine review article by Yaya Ramhat-Samii and his student, which affirms and
> confirms the findings of my research team's efforts (in particular)).
I think one could easily argue there is nothing really new with
fractal antennas. They use no new mechanisms or theory of operation as
compared to other older antennas.
>
> Nor are they likely to be part of the amateur community, given the sentiment
> Art has articulated so clearly. Thus we have a strange situation where in the
> next two or three years, amateurs use G5RV's and screwdriver antennas, while
> the wireless devices around them use, well, something else. It is happening: I
> know.
Well, shazzam! as Gomer would say. I wonder why or why not? Why are
fractals not a big hit with amateurs? I can tell you. They do not fit
the job at hand very well. Where are fractals in regular use today?
I've only seen the ones that stick in cordless phones. I can almost
assure you if any device in use today is not using a fractal antenna,
it's because it's possible to use something better.
>
> The interesting issue is which will survive:-- amateurs or fractal antennas? I
> don't mean that in some spiteful way, but I fear for our great hobby and use
> this as an example of the great disconnect we have technically these days.
A load of caca. Do you really think if the fractal antenna went away,
the amateurs would also? We were here before fractal, and will be
after. If we have a disconnect these days, it's because amateur radio
has become hi tech CB. Many could care less. They just want to yik yak
on a longer range scale.
>
> IMHO, the direction we need to go is not in some technical growth--its too late
> for that-- but towards preparedness for emergency communication and monitoring.
> We are very good listeners:-)
I've been prepared for all that malarky for years and years.
>
> We need the OO program again.
Yea. Like we need a frectal probe. I've seen goofball OO's writing up
people for not ID'ing, when in fact the people in question were all
ID'ing in morse code. You would think a OO would be able to copy code.
This is about the only difference I have with Riley on enforcement
issues. He thinks OO's are good idea. I don't. I truly think many are
just too damn stupid for the job, and then get carried away with
themselves as "the radio police". Let the fcc play radio cop if they
feel that is needed.
Oh, yea... Lets not forget Art's antenna question. No, I don't think
using a tunable loop and dipole combo would work. Why? Consider
parallel dipoles. When you change to one band or the other, the unused
legs show a high impedance and are neglected. I would think the same
thing would happen using the loopadipole.
Sure, you could tune the loop, but the dipole legs will still show a
high impedance, unless you just happen to try it where it's resonant.
In that case, the loop would be doing most of the work of radiating.
And a small loop is generally not up to par compared to a dipole. MK
'Doc
Art,
Given your description;
"If one has a dipole where inbetween the feed points a loop with
a
variable capacitor is inserted we then have a collinear antenna
for
frequences in the same range as the original loop antenna if the
dipoles were built to 20 metre lengths."
Where do you make the connections between the loop and the two
halves of the dipole?
'Doc
Reg Edwards
> I find myself quite sentimental re. Legs. :)
===========================
Dear sdb, in that case I suggest you hang on to 'em. As for me I take
pills to keep mine going. ;o)
---
Reg.
Art Unwin KB9MZ
> >variable capacitor is inserted we then have a collinear antenna for
> >frequences in the same range as the original loop antenna if the
> >dipoles were built to 20 metre lengths.
>
> Hi Art,
>
> This is difficult to follow. I can only guess you have described a
> remotely tuned gamma loop match to an opportunistic radiator.
>
> 73's
> Richard Clark, KB7QHC
Well I suppose we are all getting a bit older, a picture
is what you are asking for unless you are looking for a 'Hoos on
first'
type scenario, so here goes.
xxxxxxICxxxxx
x x
A xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxB
x x
x x
x x
xx
xx
xx
Now Richard, the straight line is a half wave dipole.(A-B )
For simplicity sake the 'loop' is in the form of a rectangle
but it can easily be made in a circular form. At the top of the loop
we have a capacitor 'IC' which can be fixed or a variable form.
So the above is basically a combination loop/dipole antenna.
So what does the above give you? To save you figuring it out
the above gives you a variable frequency antenna with a higher
efficiency
than a loop antenna alone. A less complicated capacitor and a more
user friendly antenna with respect to tuning. It also provides a small
collinear gain that neither the loop or the dipole alone can provide.
Now the Zepp provides the collinear gain by adding part of the
transmission line to the antenna but it only provides for a single
frequency. Ofcourse we can add a tuner to vary the frequency response
by using the whole antenna SYSTEM, but it does not supply a superior
antenna to the loop/dipole.
When comparing a trapped dipole for say three frequency bands I would
suggest the combination antenna is far superior but if you disagree I
would be happy to hear why. Ofcourse, if you still don't understand
the antenna i.e. the picture.......! With respect to feeding I show a
delta match and I would imagine the type and point of feed could be
almost anywhere.( the feed that you described probably could be used
also.
Now one could compare radiation patterns or compare what the 'loop'
portion does
compared to a 'stub' and then add up the advantages ,many of the
'old' wire designs could well be updated to be more user friendy.
It is my personal opinion that the combination antenna is far more
versatile,
user friendly and supplies better gain over a range of frequency than
the majority of single wire antennas now shown and if it could only
make one antenna book it could be as Reg says, plagarised,copied, or
pointed to by the experts so it will be more widely utilized and
antenna designs would not stagnate, which is precisely the point I am
making.
Richard Clark
>we have a capacitor 'IC' which can be fixed or a variable form.
This begs the observation, if IC is fixed, that antenna is no longer a
multiband design - clearly this is not your intention so why mention
it?
>So what does the above give you?
A large, variable gamma match; so large that it contributes to the
radiation if I follow your description.
>When comparing a trapped dipole for say three frequency bands I would
>suggest the combination antenna is far superior but if you disagree I
>would be happy to hear why.
Hi Art,
That is simply responded to that few here would consider "far
superior" to qualify at a less than 1 dB variation. Plus you have the
added complexity of turning that variable capacitor to achieve
multiband performance. The trapped dipole already works multiband,
you have to come up with a real gain differential to qualify for even
"modestly superior."
Art Unwin KB9MZ
> frac...@aol.com (Fractenna) wrote in message
> > Hi Richard,
> >
> > I hear denial, perhaps unintentional.
> >
> > The perception that antennas are, well, an old and hoary field is clearly wrong
> > in the face of developments, still happenng.
>
> Oh Really?
> >
> Oh, yea... Lets not forget Art's antenna question. No, I don't think
> using a tunable loop and dipole combo would work. Why? Consider
> parallel dipoles. When you change to one band or the other, the unused
> legs show a high impedance and are neglected. I would think the same
> thing would happen using the loopadipole.
> Sure, you could tune the loop, but the dipole legs will still show a
> high impedance, unless you just happen to try it where it's resonant.
> In that case, the loop would be doing most of the work of radiating.
> And a small loop is generally not up to par compared to a dipole. MK
You make my point so clearly. You have dismissed the antenna outright
without looking for possible advantages and do a diservice to ham
radio without giving it a shot PROBABLY because it is not in an arrl
ANTENNA BOOK , AND YOU ARE SO...SO WRONG. I have used this antenna for
years and I know it works and want to share it with all. I also want
to share with new amateurs that experimenting with fishing poles with
a conductive surface is so much cheaper than buying telescopic tubing
unfortunately these things are passed by unless utterred by a 'known'
person or it is a book. I would love to hear from a novice ham who has
spread his wings by making a log periodic using poles with an aluminum
surface
instead of that shown in the antenna book made of wire and string to
achieve lightness.
So do yourself a favour, try it a use a computor program to check
it out or maybe Reg will modify his 'loop' programs to prove my point
so we can review the overall subject of 'stagnating antenna designs'
rather than presenting a 'off the cuff' notion without thinking it
out. If it does not have merit you have the option of saying 'I told
you so' or conversely you can rate the merit of the antenna
advantages/disadvantages to the enjoyment of all.
Nothing personal intended, but please note that no one has stated so
far that it is without merit , because it is not yet 'written in the
book'.
Have a great week end
Art
Richard Harrison
"With respect to feeding I show a delta match----."
Art seema to have a definite antenna in mind, but he raised a question
of why innovation seems automatically rejected on arrival.
People are invested in the status quo. That`s why they reject
innovation.
Why isn`t more written about connecting to antennas of opportunity? Too
hard to predict results and who would profit from this activity? Maybe
the practitioner and a tuner maker or two.
Art Unwin KB9MZ
simple asit gets both to make or check out with the computor.
> >we have a capacitor 'IC' which can be fixed or a variable form.
>
> This begs the observation, if IC is fixed, that antenna is no longer a
> multiband design - clearly this is not your intention so why mention
> it?
Going back to my initial post where I compare to a zepp which is
usually made for a fixed frequency, it would hardly be fair to compare
with a design that has a VARIABLE capacitor. There is no snake oil
involved here.
>
> >So what does the above give you?
Actualy it doesnt, iyt takes the place of the transmition line stub
and the center portion of a dipole which contributes to those side
lobes on the zepp patten where the radiation created to form a
collinear does not fully cancel.
To make this capacitor variable suggests to me that multiple feed
lines to
obtain multi frequency use for a zep could be replaced. Merit, that is
for the experts to decide.
>
> A large, variable gamma match; so large that it contributes to the
> radiation if I follow your description.
Well I do not see where the large gamma match which is variable comes
about
but yes a gamma match radiates but also supplies an impedance that can
easily be
matched. Again merit is in the eye of the beholder.
>
> >When comparing a trapped dipole for say three frequency bands I would
> >suggest the combination antenna is far superior but if you disagree I
> >would be happy to hear why.
>
> Hi Art,
>
> That is simply responded to that few here would consider "far
> superior" to qualify at a less than 1 dB variation. Plus you have the
> added complexity of turning that variable capacitor to achieve
> multiband performance. The trapped dipole already works multiband,
> you have to come up with a real gain differential to qualify for even
> "modestly superior."
All dipoles made for a particular band has quite a variation with
respect to gain with a high gain only met at a particular frequency,
nobody high lights the low gain at the end of the bands but to the
amateur this is very interested.
Again it is the eye of the beholder. The trapped antenna does not
radiate along the whole length of the antenna so the gain loss is
heavy where the combination
antenna radiates from each end of the antenna and provides the added
gains for a collinear. Superior ? Try it out and compare the numbers
and see if anything of interest show up.
You also mentioned the complexity of turning the capacitor and I
suppose that is a huge demerit in some eyes but it is really as simple
as it gets and accepted for the loop, so it is not so complex to stop
people using a loop antenna despite the difficulties encountered with
that particular antenna
So Richard, knowing you have considerable expertise with the computor
and antennas please do me the honour of checking the figures so the
response will be factual and informative to all.
Hang in there buddy, sometimes I ask at the dinner table where the
salt is
and all hasten to point out that it is right in front of my eyes, but
yet I did not see it.
Regards
Art
Art Unwin KB9MZ
simple asit gets both to make or check out with the computor.
> >we have a capacitor 'IC' which can be fixed or a variable form.
>
> This begs the observation, if IC is fixed, that antenna is no longer a
> multiband design - clearly this is not your intention so why mention
> it?
Going back to my initial post where I compare to a zepp which is
usually made for a fixed frequency, it would hardly be fair to compare
with a design that has a VARIABLE capacitor. There is no snake oil
involved here.
>
> >So what does the above give you?
Actualy it doesnt, iyt takes the place of the transmition line stub
and the center portion of a dipole which contributes to those side
lobes on the zepp patten where the radiation created to form a
collinear does not fully cancel.
To make this capacitor variable suggests to me that multiple feed
lines to
obtain multi frequency use for a zep could be replaced. Merit, that is
for the experts to decide.
>
> A large, variable gamma match; so large that it contributes to the
> radiation if I follow your description.
Well I do not see where the large gamma match which is variable comes
about
but yes a gamma match radiates but also supplies an impedance that can
easily be
matched. Again merit is in the eye of the beholder.
>
> >When comparing a trapped dipole for say three frequency bands I would
> >suggest the combination antenna is far superior but if you disagree I
> >would be happy to hear why.
>
> Hi Art,
>
> That is simply responded to that few here would consider "far
> superior" to qualify at a less than 1 dB variation. Plus you have the
> added complexity of turning that variable capacitor to achieve
> multiband performance. The trapped dipole already works multiband,
> you have to come up with a real gain differential to qualify for even
> "modestly superior."
All dipoles made for a particular band has quite a variation with
respect to gain with a high gain only met at a particular frequency,
nobody high lights the low gain at the end of the bands but to the
amateur this is very interested.
Again it is the eye of the beholder. The trapped antenna does not
radiate along the whole length of the antenna so the gain loss is
heavy where the combination
antenna radiates from each end of the antenna and provides the added
gains for a collinear. Superior ? Try it out and compare the numbers
and see if anything of interest show up.
You also mentioned the complexity of turning the capacitor and I
suppose that is a huge demerit in some eyes but it is really as simple
as it gets and accepted for the loop, so it is not so complex to stop
people using a loop antenna despite the difficulties encountered with
that particular antenna
So Richard, knowing you have considerable expertise with the computor
and antennas please do me the honour of checking the figures so the
response will be factual and informative to all.
Hang in there buddy, sometimes I ask at the dinner table where the
salt is
and all hasten to point out that it is right in front of my eyes, but
yet I did not see it.
Regards
Art
>
Roy Lewallen
mentioned it quite a few times before on this newsgroup. I encourage you
and others to take a look at the ARRL Antenna Compendium. Last I
checked, six volumes of this have been published. They're chock full of
innovative antenna designs. Some are particularly good at solving some
problem or another, but nearly all do so at the expense of something
else -- efficiency, mechanical complexity, gain or directivity (too much
or too little), and so forth. I hate to tell you, but your antenna, much
as you may like it for your particular situation, is no exception. I can
build a trap dipole to operate on several bands, feed it with 50 ohm
line, and forget it. I can hang it from two supports, or put it up as an
inverted vee from one support. I can build the traps from a few pieces
of PVC pipe and some coax. No tuning, manual or automatic, is required.
That doesn't make it better than your antenna. But it certainly has some
advantages for a lot of users. I personally prefer it for my uses, over
finding a high voltage variable capacitor of adequate range,
weatherproofing it, and providing a means of remote tuning. Each to his
own. You can take any two antennas and write a list of advantages and
disadvantages, and seldom will one come out on top in all regards for
all users.
The place for new and innovative antennas is publications like the
Antenna Compendium, or books like Moxon's _HF Antennas For All
Locations_. The ARRL Handbook and Antenna Book are the appropriate
places for antennas that many people have found to be useful and
advantageous and are using as a result. Out of all the antennas in all
the textbooks, in all the Antenna Compendium volumes, QST, RadCom, CQ,
ComQ, Ham Radio articles over the years, in books like Moxon's, is your
antenna really so wonderful that it should merit inclusion in the ARRL
Hanbook among the very few that can be included? Is it really so much
better than the thousands of other innovative designs?
Here's how to find out. Write it up and submit it to the ARRL for
publication in the Antenna Compendium. If you have a problem with that,
choose any other magazine of your choice. Or post it on your web page
and tell your friends about it. Then wait and let the test of time
determine whether yours is really so great as to attract a following
large enough to put it in a class with tried and popular antennas. Or
whether it'll join the thousands of other designs that are great for
some and not so great for others.
You seem to feel that your antenna isn't being recognized by the world
because the ARRL doesn't include it in their Handbook. But I think you
have it backward -- the ARRL doesn't include it in the Handbook because
not enough people have adopted it to separate it from the vast hordes of
innovative antennas vying for attention. It's up to you, not the ARRL,
to convince people that it's the greatest thing since canned beer. Only
then will they grab their openers and join your party.
Roy Lewallen, W7EL
Art Unwin KB9MZ
>
snip
> confirms the findings of my research team's efforts (in particular)).
>
> Nor are they likely to be part of the amateur community, given the sentiment
> Art has articulated so clearly. Thus we have a strange situation where in the
> next two or three years, amateurs use G5RV's and screwdriver antennas, while
> the wireless devices around them use, well, something else. It is happening: I
> know.
>
>
> 73,
> Chip N1IR
Chip,
I believe that I have made my point already. Comments so far have
been 'off the cuff' responses that would discourage any new ham. The
task at hand now is to persuade the knoweledgable to go beyond that
and take a few minuites with AO
or some of Roy's programs or even place dipole extensions on a loop
antenna which they may have at hand. When one of the more knowlegable
finally succumbs and does a modicom of leg work for himself rather
than leaning on hunches or looking up 'the book' will the true meaning
of my original post become apparent regarding 'stagnation.' All I am
pointing out is that we all tend to dismiss the new or different as we
get older, focussing on hunches or the absence of articles to take the
time to verify for oneself. In this particular case I have made some
sweeping statements and asked for verication based on merit BOTH the
good and the bad which on this forum is like pulling teeth but ONLY
when completed will I have met with success regarding the original
post on
'antenna stagnation' be fully understood.
Regards
Art
Bob Miller
>
>You make my point so clearly. You have dismissed the antenna outright
>without looking for possible advantages and do a diservice to ham
>radio without giving it a shot PROBABLY because it is not in an arrl
>ANTENNA BOOK , AND YOU ARE SO...SO WRONG. I have used this antenna for
>years and I know it works and want to share it with all.
Curious, how many supports does it take to hold up your combined dipole-loop?
That's a consideration for me.
Tnx,
Bob
k5qwg
Rick Littlefield
we
get older, focussing on hunches or the absence of articles to take the
time to verify for oneself.<
Is that a southern mouse in your pocket, Art? ("we all"). Personally, I think
"seasoned judgement" and "callous disregard" aren't the same thing. If your
idea is hot, someone will discover it and spread the word. That's why there are
more G5RVs than EHs hanging in the trees.
Rick K1BQT
Wes
|If one looks at present day antenna books such as the ARRL offerings
|you would be hard put to shell out some money if you already had a previous
|edition that had some age on it
[snip]
Art, Art, Art, calm down and steady yourself.
It may be that your design has merit, but in reading all of the prior
posts I'll be damned if I can figure out exactly what you're talking
about. You are going to have to publish something understandable on a
web site or on paper with some readable illustrations and analysis
before you can legitimately claim that you are being ignored.
I'm as eager as anyone to challenge the conventional wisdom of some
"prior art" as you might conclude by reading my thoughts on the
"advantages" of ladderline and "G5RV" antennas. I might be all wet
with my conclusions, but I put 'em out there for discussion, in what I
hope is understandable form.
I know that Dean Straw, editor of the Antenna Compendiums and the
Antenna Handbook, is begging for something fresh to publish. So if
you are unhappy about the "tired old, worn out designs" that are
regurgitated annually, do something about it. Write it up and send it
in.
73,
Wes
:-) Bill
> idea is hot, someone will discover it and spread the word. That's why there are
> more G5RVs than EHs hanging in the trees.
>
> Rick K1BQT
One website says the EH works equally well in a basement. Probably
true.
-BM WX4A
Art Unwin KB9MZ
Richard,
I may have misread your post
but I do not have any monetary interest in this style of antenna or
any others
I withdrew from the patent scene some years ago and withdrew from
amateur radio for a while. If somebody picks up the torch and gives a
'how to' post on how to utelise a 'stamp' to automate it I could not
be happier. If they make some money while pursuing the idea then good
luck to them. My post is to strictly make a point about 'stagnation'
and what creates it. The basic idea IS in old antenna books where a
ham shows a instrument or antenna formed in a figure '8' to show how
one can desensitise structures or poles that may be affecting other
wire antennas . It is not a new basic idea nor is the use of 14 foot
fishing blanks
or driving existing verticle structures to make a variable frequency
antennas
or its use as a dipole with a full frequency sweep or infact any
antenna that presently uses a stub where replacement uprates the
frequency sweep. Yours is the last post that appeares on my computor
but at the end of the day I am hoping that one expert will not dismiss
it with hunches and give it some validity
if my posts have merit.
P.S. Were you the person I sent a picture to where I showed a 80 foot
plus long antenna with 13 elements made of fibre glass poles ? I have
not been well for a while and I have slightly lost track of things
Regards
Art KB9MZ
coated with uluminum wrap ?
Richard Clark
>Richard Clark <kb7...@attbi.com> wrote in message news:<bta3ku0bs0pj175bt...@4ax.com>...
>> On 25 Jul 2002 20:57:51 -0700, aun...@fgi.net (Art Unwin KB9MZ) wrote:
>> >we have a capacitor 'IC' which can be fixed or a variable form.
>>
>> This begs the observation, if IC is fixed, that antenna is no longer a
>> multiband design - clearly this is not your intention so why mention
>> it?
>Going back to my initial post where I compare to a zepp which is
>usually made for a fixed frequency, it would hardly be fair to compare
>with a design that has a VARIABLE capacitor. There is no snake oil
>involved here.
Hi Art,
Going back to your initial post has nothing to do with multiband
requirements driving the necessity of a variable capacitor for the
design you offer and the specifications you claim.
Further, if you want to champion an antenna, it is very poor form to
choose poor examples to compare it in contest. Skip the discussion of
the Zepp altogether, unless you are more interested in its exclusion
from the canon of antennas than you are in your own's inclusion.
>>
>> >So what does the above give you?
>Actualy it doesnt,
Art, do you realize how hard it is to follow your logic when you
directly contradict yourself? The two lines above were both authored
by you.
>> A large, variable gamma match; so large that it contributes to the
>> radiation if I follow your description.
>Well I do not see where the large gamma match which is variable comes
>about
>but yes a gamma match radiates but also supplies an impedance that can
>easily be
>matched. Again merit is in the eye of the beholder.
Who is talking about merit here? Show me more than a dB before we get
into the emotional specification.
>The trapped antenna does not
>radiate along the whole length of the antenna so the gain loss is
>heavy where the combination
>antenna radiates from each end of the antenna and provides the added
>gains for a collinear. Superior ? Try it out and compare the numbers
>and see if anything of interest show up.
Art, I have been doing that for quite a few years now. I have seen
many interesting things - and to the surprise, perhaps, of some, they
were fractals.
Surprise, Interest. Each of these emotions absolutely did not
translate into the pinnacle of performance. For myself, surprise and
interest led me to literally thousands of failures (most of them
available for viewing at my pages). But amongst those thousand
abominations I found that I had gained in insight through the
investigation of them.
>So Richard, knowing you have considerable expertise with the computor
>and antennas please do me the honour of checking the figures so the
>response will be factual and informative to all.
>Hang in there buddy, sometimes I ask at the dinner table where the
>salt is
>and all hasten to point out that it is right in front of my eyes, but
>yet I did not see it.
>Regards
>Art
Art, it is your responsibility to provide an exact model to us, not
for me to rummage around with equivalents. This is a minimum
requirement to enter the canon of antenna.
Richard Clark
>That's why there are
>more G5RVs than EHs hanging in the trees.
>
>Rick K1BQT
mots juste
Richard Clark
(Richard Harrison) wrote:
>
>People are invested in the status quo. That`s why they reject
>innovation.
>
Hi Richard,
No one rejects innovation on the basis of status quo, they reject the
failed challengers of the status quo.
We would all still be in caves otherwise.
W.G Ewald
> Where are fractals in regular use today?
>I've only seen the ones that stick in cordless phones.
Mark --
What fractal antennas are in cordless phones? I have not seen any
cordless phones advertised with "fractal antenna" as a feature.
WGE
Mark Keith
> You make my point so clearly. You have dismissed the antenna outright
> without looking for possible advantages and do a diservice to ham
> radio without giving it a shot PROBABLY because it is not in an arrl
> ANTENNA BOOK , AND YOU ARE SO...SO WRONG. I have used this antenna for
> years and I know it works and want to share it with all.
Have you measured the gain when used at frequencies far off from the
1/2 wave dipole length?
I also want
> to share with new amateurs that experimenting with fishing poles with
> a conductive surface is so much cheaper than buying telescopic tubing
> unfortunately these things are passed by unless utterred by a 'known'
> person or it is a book. I would love to hear from a novice ham who has
> spread his wings by making a log periodic using poles with an aluminum
> surface
> instead of that shown in the antenna book made of wire and string to
> achieve lightness.
Oh, I have no problems with such foil methods. Whatever works...The
only thing with foil is trying to get good connections. And then keep
them with the effects of wx. Can't solder to it too well. I have done
things like make vhf yagis from coathanger wire...
> So do yourself a favour, try it a use a computor program to check
> it out or maybe Reg will modify his 'loop' programs to prove my point
> so we can review the overall subject of 'stagnating antenna designs'
> rather than presenting a 'off the cuff' notion without thinking it
> out. If it does not have merit you have the option of saying 'I told
> you so' or conversely you can rate the merit of the antenna
> advantages/disadvantages to the enjoyment of all.
That would be no problem to model. Or at least I don't think it would
be...
I'm willing to give it a shot. But my comments were not without
thought.
I still am not sure how you are going to couple power to a radiator
that shows a high impedance to the feedline when you have the loop
tuned and showing a fairly low impedance. IE: 50 ohm coax feeding a
small tunable loop parallel with a 1/2 wave dipole at a certain freq.
Lets say the dipole is cut for 40m. Now go to 20m, and tune the loop
for 20m use. Seems to me if it shows a low impedance to the line, and
the dipole show a high impedance, such as a full wavelength would, the
loop would accept the majority of the power. And being the loop would
not be too efficient, I don't really see how the performance on 20m,
would equal or exceed the performance on 40m, where it would naturally
be good being the dipole is resonant. If I'm missing something here,
maybe someone will jump in... Am I describing the antenna correctly?
MK
Art Unwin KB9MZ
O.K. Wes if my computor works o.k this morning listen to my story.
My training is that of a engineer with G.E but after 25 years I had to
retire because of heart attack, many depression periods, sleep apnia
e.t.c so I can understand that my writing is not all it should be.
Many years ago Moxon showed this antenna in the British Radcom,
unfortunatly he did not go far enough with it plus he called it the
case of the disapearing induntance. Progress that stopped him was an
everyday thing for me and I made these antennas plus a lot more. Later
it was published in his book, I forget the name now but still it
didnot attract attention. After talking with him at his home about the
variable cylinder type of capacitors within booms e.t.c. I asked a
friend of mine to show my stuff to the British ham assoc where they
viewed it with some suspision.
I took out a patent in fact a series of patents some of which I
abandoned with discust before the examination period because I
recieved similar comments from this group as I am getting now and at
that time I had also placed on the net a page showing construction
methods.
Since it got no follow up interest I got the AO program and worked
with it. Unfortunately in those early days I made many mistaks using
the program that I began to doubt myself. Eventually I amnaged to get
the University of Illinois to do a study on the sly ( they were
working on fractals at that time, and they confirmed my work. I then
gave a couple of lectures at the Peoria ham fest which that year was
the premier hamfest of the ARRL for that year. Prior to giving those
lectures I sent the material to Dean Straw you was nice enough to give
me some tips on presenting it.This post is getting too long so I will
finish.
But for those who are willing to join the rest of the lemmings in
following the crowd start thinking back to first principles and
consider what you get when you add two frequencies as a tip for how
this antenna works. It only takes ten lines of info for a AO style
conformation of what I am claiming and I am willing to work with
anybody who is willing to give me a modicom of repect and bear with
my obvious difficulty of explaining things with my present problems.
Best regards to all
Art UNwin
KB9MZ
J. McLaughlin
Please supply the patent numbers and we will all be able to "see"
the antenna that you invented. We all understand that you are having
difficulty in expressing and describing the antenna using words.
Thanks, Mac N8TT
--
J. Mc Laughlin - Michigan USA
Home: J...@Power-Net.Net
"Art Unwin KB9MZ" <aun...@fgi.net> wrote in message
J. McLaughlin
base.
5,625,367 Variable capacitance antenna for multiband reception and
transmission was issued April 29, 1997 on an application filed on March
20, 1995.
5,790,081 Constant impedance matching system was issued on August 4,
1998 based on an application filed on January 30, 1996.
The PTO's data base only provides the means to search for specific
inventors within patents issued since about 1976.
Richard Harrison
"---I do not have any menetary interest in this style of antenna or any
others."
I`m sorry. I didn`t intend to insinuate Art was motivated by greed or
even monetary interest. I said people reject innovation because they are
invested in the status quo People invest effort in turning ideas into
reality That`s good, but they often want to believe that their time was
well spent, and this may be devoid of profit motive.
Profit is necessary to a commercial venture. Profit is good. People are
stubborn. We can`t readily change that.
Art Unwin KB9MZ
> Art H. Unwin, of Bloomington, IL, has two US patents in the PTO's data
> base.
>
> 5,625,367 Variable capacitance antenna for multiband reception and
> transmission was issued April 29, 1997 on an application filed on March
> 20, 1995.
>
> 5,790,081 Constant impedance matching system was issued on August 4,
> 1998 based on an application filed on January 30, 1996.
>
> The PTO's data base only provides the means to search for specific
> inventors within patents issued since about 1976.
>
> Mac N8TT
Mac, I was unaware your e mails were also being posted here.
The reason I was not forthcomming with patent details e.t.c.
is they are a source of embarasement to me.
What I originally submitted bore little resemblace to what came out
as many on this group can attest to.
Patents of mine prior to these have no relevance to the subject at hand.
Art Unwin KB9MZ
The antenna described was talked about to emphasize what the title
stated.
Instead of auguing the point on this antenna which is presenting a
problem to many. since you say you have made many anttenas have you
ever thought about two reflectors? If you go by what is said in
theArrl books it would say that this would lower the impedance which
gives cause who go solely by the book not to attempt it.were as the
reverse istrue and by now we should have many commercial antennas with
two reflectors. No problem withe good job that the book does
but it is still written that way because of what Reg would call
regurgitation.
If it is written every place it then becomes iron clad fact.
Please dont feel that you have to defend yourself this is not
personal.
Take comfort in one post where it was stated that we reject innovation
that does not come up to the mark, you are in good company.
No offense intended
Regards
Art kB9MZ
Richard Clark
>Take comfort in one post where it was stated that we reject innovation
>that does not come up to the mark,
Hi Art,
Actually I put it as we (society, not necessarily this group) rejects
what does not work which by definition is poor innovation.
J. McLaughlin
I was only trying to provide more detail about the type of antenna
being discussed. Patents tend to be more lucid than what is convenient
to describe here. Patents also usually have drawings that help
communicate.
It is a remarkable achievement that you were able to prosecute the
two patents by yourself. I can not understand, but then there is no
need for me to understand, your expressed feelings about the patents.
Very few patents issue containing just what was in the initial
application.
Perhaps now that the patents have been identified, some investor
will arrive to help move forward the inventions.
Warm regards and keep inventing,
Mac N8TT
--
J. Mc Laughlin - Michigan USA
Home: J...@Power-Net.Net
"Art Unwin KB9MZ" <aun...@fgi.net> wrote in message
news:c4becf19.02072...@posting.google.com...
Richard Harrison
"---by now we should have many commercial antennas with two reflectors."
Is that the best use we can make of materials?
Consider the yagi. With only one reflector we can get a good
front-to-back ratio. Another reflector in the plane of the radiator and
of the first reflector, but to its rear, doesn`t have much energy to
work with. The energy is already turned around by the first reflector. A
director using about the same material as an additional reflector has a
lot more energy to act upon. The logic of a single reflector and
multiple directors seems obvious and sound to me.
I have no interest in the status quo.
Yuri Blanarovich
>Is that the best use we can make of materials?
>
>Consider the yagi. With only one reflector we can get a good
>front-to-back ratio. Another reflector in the plane of the radiator and
>of the first reflector, but to its rear, doesn`t have much energy to
>work with. The energy is already turned around by the first reflector. A
>director using about the same material as an additional reflector has a
>lot more energy to act upon. The logic of a single reflector and
>multiple directors seems obvious and sound to me.
>
>I have no interest in the status quo.
>
>Best regards, Richard Harrison, KB5WZI
>
>
>
Theoretically?
Practically, I have also found second reflector to be beneficial (back in late
70ies). At the shorter spacing it gave me better F/B and more gain than I could
have achieved with additional director needing spacing about 3 times wider.
(Saved boom aluminum.) This was "discovered" by experimentation with real
hardware models on 2m antenna test range and with Quad-Yagi combination of
elements in my Razors. (Not patented, not commercially manufactured, few built
and creamed contest records.)
Pictures can be seen at
http://members.aol.com/ve3bmv/Razors.htm
New software modeling could prove me "wrong" but I can take it :-)
Yuri, K3BU, VE3BMV, VE1BY
Richard Harrison
using it for a second reflector.
That was based on upping the gain. The dipole with a reflector might
give 5 dbd gain. Adding a director might give you 2 db more gain (no
guarantees). An additional reflector is likely to give less gain
improvement to a dipole with a reflector, as it has little energy to
work with.
There are other factors. Front-to-back ratio might be improved using two
reflectors, and bandwidth might be better. The dipole with one parasitic
reflector has a bandwidth of about 30%. A 3-element yagi (reflector,
radiator, director) typically has a bandwidth of only about 6%.
Additionl reflectors are unlikely to do much and that includes narrowing
the bandwidth.
Evidence of the bandwidth-friendly status of multiple reflectors is
probably seen in the TV antennas on British roofs. Many of these seem to
have 3 horizontal reflecting rods in a vertical plane if my memory is
correct.
A lot has to do with the use that is to be made of the antenna.
Richard Harrison
"Practically, I have also found second reflector to be beneficial (back
gain than I could have achieved with additional director needing about 3
times wider."
Can`t argue with valid test data and competitive success. I would second
Art Unwin`s motion that multiple reflector antennas should be
commercially available.
Yuri`s pictures at>
http://members.aol.com/ve3bmb/Razors.htm
These are very nice and worth a look.
Art Unwin KB9MZ
> On 26 Jul 2002 20:30:55 -0700, aun...@fgi.net (Art Unwin KB9MZ) wrote:
>
> >Richard Clark <kb7...@attbi.com> wrote in message news:<bta3ku0bs0pj175bt...@4ax.com>...
> >> On 25 Jul 2002 20:57:51 -0700, aun...@fgi.net (Art Unwin KB9MZ) wrote:
> >> >we have a capacitor 'IC' which can be fixed or a variable form.
> >>
> >> This begs the observation, if IC is fixed, that antenna is no longer a
> >> multiband design - clearly this is not your intention so why mention
> >> it?
> >Going back to my initial post where I compare to a zepp which is
> >usually made for a fixed frequency, it would hardly be fair to compare
> >with a design that has a VARIABLE capacitor. There is no snake oil
> >involved here.
>
> Hi Art,
>
> Going back to your initial post has nothing to do with multiband
> requirements driving the necessity of a variable capacitor for the
> design you offer and the specifications you claim.
>
> directly contradict yourself? The two lines above were both authored
> by you.
>
>
> Richard Clark, KB7QHC
O. K. Richard it is time for me to eat crow.
! I apologise to all that I have not respoded to, I have only just
realised
that responses are not listed at the end but instead are broken up
into more thread so I apologise to those I may have offended.
2 My focus was on the continuing reprinting of the older wire antennas
for cheapness and then allowing my antenna to dominate the thread
rather than discussion of the title.
3 I accept the admonitions of Roy W7EL as the normal correct ways of
doing things,and I continue to respect his wisdom
4 Believe it or not I have difficulty in accepting why this group has
a problem with my posts. If I knew how to correct it I would but for
some reason I have lost any good communications skills that I may have
had. I certainly recognise that I am not able to follow form and write
a paper,posters have certainly made that clear to me but I am unable
to correct the problem at the moment.
5 Yes I did speak of this antenna years ago on this thread and I not
surprisingly feel it has merit. I also am stubborn continually place
myself in a position of scorn. Maybe after today I can reconcile
myself that I did the best I could with a product that failed to meet
standards.
I apologise for any inconvenience or emotionalism that I have inposed
on the readers and will try harder if and when I enter later threads.
With apologise to all
Art Unwin KB9MZ.
I will now read other comments that I may not have read.
Richard Harrison
http://members.aol.com/ve3bmv/Razors.htm
I am still a lousy typist and data machines don`t tolerate my mistakes.
Art Unwin KB9MZ
The Group
Before we get too deep with this offshoot regarding two reflectors,
where I have probably overeached to support my other statements,
consider the following.
There is no doubt in my mind that for present HF antennas and the
like, two reflectors has yet to be proved beneficial. For moon bounce
and the like of which I have no experience modification of radiation
pattern and impedance are paramount. In an experiment which I
performed and on which Roy W7EL graciously placed on his page a
simulating program of the antenna which consisted of 13 elements
including reflectors, where it was shown densely populated element
antennas provided no extra gain over those presently in use ( tho in
my mind they had no less gain)and the only thing for that particular
HF antenna, was that the second reflector element produced a HIGHER
impedance!
Since antenna manufactures make great note of improving for gain on
the status quo creats unuseable LOW impedances at least for HF
antennas. I extrapolated perhaps incorrectly,that the two reflectors
may well have value where gain is everything as well as the radiation
pattern, ala moon bounce antennas.
But if a statement is made where the use of a second reflector
IMPROVES the pattern then the question of adding to the statement LOW
impedance is up for question.
As I stated earlier, I may be over reaching in using this as an
example and I also do not have experience in areas above HF .
On another side note with respect to aluminum clad fishing poles,
there is in present day use pre adhesive coated aluminum which is
used in the building arena for long term use which allows for elements
with zero number of joints for those cases where the joint resistances
is bothersome. In addition for those who have to have a joint, most
hams have seen at hamfests demonstrations of the use of a blow torch
and a suitable 'stick' for want of a definable word connect aluminum
rods to .002" thick alumanum wrap with little difficulty, but to each
his own. It is undeniable that for those with little cash on hand that
telescopic aluminum for ham use is extremely expensive and where a
search for more reasonable methods and costs are in order.
I have taken extra care with this post but it probably wiil still
confuse most readers if past experiences are taken into account.
If it does, please let that part of the subject to drop and allow the
use of two reflectors to pass away from this thread.
Thank you for your indulgence.
Art Unwin KB9MZ
Yuri Blanarovich
>I suggested a director might be a better use for more material than
>using it for a second reflector.
>
>That was based on upping the gain. The dipole with a reflector might
>give 5 dbd gain. Adding a director might give you 2 db more gain (no
>guarantees). An additional reflector is likely to give less gain
>improvement to a dipole with a reflector, as it has little energy to
>work with.
>
>
>
>
One note of caution, the above might valid in simple, few element antennas.
Antennas with more than 5-6 elements start losing F/B and this is when second
reflector comes to the rescue and offers some benefits. The 15m Razors shown at
http://members.aol.com/ve3bmv/Razors.htm
have configuration: Yagi reflector, Quad reflector, dual Quad driven log cell,
Quad director and 2 Yagi directors on a 62 ft boom.
I played with that stuff on the 2m antenna test range for three months during
long Canadian winter nights and that was the best I could come up with. More
emphasis was on the clean pattern (best F/B and F/S) rather than max gain. They
are practically flat 1.1:1 across the band.
I am trying to find some free time to plug the Razors into the EZNEC, but QRL
with resort is in the way. So far I tried to compare my 3 el. Quad design and
simulate it in the software and there was some discrepancy. I ran it also
through AO. I need to do some correlating with 2m models (much easier than with
real HF antennas) and see what I get.
So far when some friends tried to do multielement Razors in software, they tell
me that they have no gain and lousy F/B and pattern with high angle back lobes.
Well, I have seen real antennas performing on 2m (compared to KLM "standards")
and then scaled to HF and I know how they work. I am looking forward to explore
this, just need to shake off the QRL.
Yuri, K3BU
Fractenna
>fractal antennas are listed under the sections on
>dummy loads and insulators.
> 'Doc
My goodness; it doesn't seem to be there under those rubrics. Perhaps you have
not understood the facts correctly? Look again and fill us in.
73,
Chip N1IR