Tony, you are absolutely right. There isn't a ultra-compact antenna
design that competes well with a full-sized antenna out there anywhere.
It's the "mousetrap" that, if it can be built, will become the most
popular device in any Amateur's setup.
The way I see it, this is AMATEUR radio for most of us. We do things for
the "fun" of it, not because it's a contest, a business or to document
academic achievement.
It's true that never in the 100 years of antenna design work since
Marconi hung his first wire in the air has someone found something new
that fell outside of the engineering principles for antenna design. The
principles have been documented, tested and expanded upon since
Marconi's first empirical designs showed promise. These principles have
been used again and again to predict how a new type of antenna would
work, and then confirmed when the antennas were actually built and
tested. They have led to every antenna design in current use.
So you are working against very long odds Even so, messing about with an
antenna design that is interesting to you, no matter how unlikely, can
be a lot of fun and very instructive. Going through the process of
figuring out how well it works (or doesn't work) and why will provide a
wealth of knowledge that you may not have gained before.
In the field of antenna design, determining how something works is
equivalent with evaluating the validity of Extra-Sensory Perception. For
most Hams it becomes a process of collecting impressions and dealing
with incomplete statistical data. Very few of us have adequate test
ranges on which we can compare the design against other designs under
identical conditions. The best we can do - sometimes - is to put up two
antennas in a way that they don't interfere with each other and do very
fast A/B switching between the two to compare signals. Even then, our
data may be flawed because of differences in polarization, differences
in lobe positions and other factors that may have a dramatic effect on
one signal but not on another.
Many Hams, like ESP practitioners, are happy with anecdotal evidence.
They say, "I got a good signal report from a DX station so my antenna
works FB". That's just like the ESP practitioner who predicts something
that actually happened so he/she is obviously psychic. That drives
scientists nuts because the "scientific method" demands that a valid
experiment can be repeated at will. If it cannot be repeated, it is
suspected of being a statistical fluke. At the very least it cannot be
used as the basis for further design work because we want things that
work when we expect them to. How many people would be happy with a TV
set that turned on "once in a while" when we pushed the button? Or an
automobile that started "once in a while" when we turned the key? If an
engineer is going to use the data to design something useful, it must
work as planned every time unless there is an obvious and repairable
malfunction.
Whenever a new idea is put forward, engineers will look at it to see if
there is something "new" in the design or performance. The first step
must be to verify the measurements that were taken. Once the data is
confirmed, the design is tested against current principles to see if
they predict those results. If not, we start looking for "why". Finding
out "why" can reveal a new engineering principle. More often, finding
out "why" discloses errors in the measurement and testing methods and we
learn something about devising better experiments.
Sometimes people announce something for less-than-scientific reasons.
Remember "Cold Fusion"?
In the case of the E-H antenna, I was alerted by their insistence upon
calling a very common and well-known circuit by a "new" name. I asked
"why"? Are they trying to make it sound "new"? That's exactly what the
E-H antenna documentation does with their "phase-shift network". It's
what any Ham would call a "matching network". Such a network does do two
things: converts the impedance at the antenna to what the source (the
transmitter) requires AND it corrects for reactance in the circuit. We
correct reactance to put the voltage and current in phase. That's
exactly what the E-H network does. It is nothing more than a common
"matching network". Trying to call a "matching network" by a new name
without explaining that it is exactly what most hams have used at one
time or another seems like they are trying to use some "smoke and
mirrors" to make their design sound more different than it actually is.
Applying current engineering principles to the design, as John has done,
discloses that very little r-f will be radiated by the "antenna" portion
of the E-H design. John noted that the feedline can be a very effective
radiator in this case. That would account for some of the reports of
good performance from it. So, by all means, if it interests you go ahead
and find a way to test the antenna without a feedline! If it still
radiates as well or if it doesn't radiate, something has been learned.
If it works, perhaps a new principle may be hidden in there somewhere
that turns upside down everything ever done with antennas to date, or
there is some other reason that we haven't discovered yet.
People like John, myself or anyone else who offers alternative
explanations for there being a new principle at work on the E-H antenna
are NOT opposing what you are doing.
John is giving of his time to help you test your hypothesis. He and
others are offering possible explanations for your successes in order to
help you understand and appreciate what you are doing.
That's the first step in uncovering a new engineering principle. Testing
the experiment to see if there are any alternative explanations, then -
as you are doing by removing the feedline - changing the experiment to
see if the alternative explanation is true. When, and only when we have
exhausted every possible alternative explanation for why something is
"working" and it still works in spite of running counter to what we
know, will we then know it is time to start looking for some new and
undiscovered principle.
Everyone who questions your results is on YOUR side! We are all
experimenters looking for "what works".
Ron AC7AC
K2 # 1289
-----Original Message-----
... I, and many others are in the area of trying to find a small compact
ant that will work well in small backyards. Most ham real estate will
allow 20-30 feet elevation up a pole but only limited radiator and
feedline length. So the EH antenna up a pole *may* provide a better
solution on 40, 80 and 160 Mters. The nearest alternative to the EH in
these circumstances is the mag loop, and that itself would be a
compromise on 40, 80 and 160. If there was a "conventional", "good"
solution to this already, there would be one in evey small backyard.
Regards,
Tony
M3CJF
G7IGG