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Old December 18th 06, 06:59 AM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna


wrote in message
oups.com...

John Smith mentioned the Microvert antenna, which I know
very well.
I made an extensive comparison of the RoomCap (hb9abx)
against Microvert, and was using the best Microvert available
(MV-500) for 40m.
Test at same location, both antennas at same height in
A-B configaration.
Test was performed by many rapid changes between the
two antennas, and the remote station was observing
the signal strength.
Result was, that the RoomCap was 2 s-points stronger
in average, in receiption as well as in transmission.
Rember that 2 s-points correspond to 12 dB.
A very clear result.
73s
Felix HB9ABX


Its my understanding the microvert is the HF equivalent of a "rubber duck"
antenna.


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Old December 18th 06, 07:37 AM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna

Jimmie D wrote:
...
Its my understanding the microvert is the HF equivalent of a "rubber duck"
antenna.



Microvert is certainly no full wave dipole, but for stealth they are
great. Motorhomes, camping, fishing, trailer courts, beaches, parks,
etc.--they attract little attention when disguised in a sun umbrella
(doesn't have to be functional), badminton pole, flag, etc.

Regards,
JS
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Old December 26th 06, 06:36 AM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna


"John Smith" wrote in message
...

And, yesterday I walked on water, in front of 12 witnesses.

Fortunate for you, I made a video of this! If you go to my webpage you
can purchase a high definition video in true color of this truly amazing
feat of mine, for the most reasonable price of $29.95 USD! Click here
to purchase this truly remarkable video--a real once in a lifetime
opportunity:

http://BridgeForSale.org

Regards,
JS


Blasphemy ought to have a point -- and I had the misfortune to open this on
Christmas Night. If you think the OP's assertions are bogus, maybe you
should say why. (There's enough snot being slung around in this newsgroup
for it to be declared an epidemic.)


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Old December 26th 06, 07:32 AM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna

Sal M. Onella wrote:
Blasphemy ought to have a point -- and I had the misfortune to open

this on
Christmas Night. If you think the OP's assertions are bogus, maybe you
should say why. (There's enough snot being slung around in this newsgroup
for it to be declared an epidemic.)



Very sorry you feel that way OM. Because your opinion matters to me, I
have went to the time and expense of setting up a special support
hotline for you. Just dial the following number:

1-800-call-mental-health

The nice folks there can straighten everything out ...

Regards,
JS


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Old December 26th 06, 10:09 PM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna

Let's come back to the subject here, the RoomCap
antenna:

Read what wrote a builder of the antenna:
Paul VE3UNF was answering my question, if his report is a joke, with
the following reply:

I am 60 years old - a retired airline pilot whom has flown all over the
world from small turbo props, right up to the Boeing 747 with over
21,000.0 flying hours.

I have been building antennas off and on now for 15 years at my various
QTH's.
Most of the antennas I have built came from various antenna books which
were mainly stealth type antennas, as
most of my past QTH's were in deed restricted locations. eg . attic
antennas , hidden wire antennas, vertical
antennas off of balconies, short dipoles with traps, the list goes on
and on and I have never been able to make
an antenna that for it's size can perform at all, or as well as, or
outperform this G5RV.

I moved to this location in Florida last year which has an acre and a
half and was able to build this G5RV shortly thereafter.

After reading up on your other antennas and now this antenna. I decided
to build the RoomCap out of curiosity,
-- just to see how well it performed -- in the chance that if it did
give a reasonable account of itself, -- it would be beneficial to all
those hams that I know, that cannot put up a very visible antenna -- as
I remembered how difficult and frustrating it was for me to just get on
the air when I was in Toronto. Well, I built it and I was pleasantly
surprised.

I am going to continue to test this antenna with the G5RV and keep
recording the results irregardless of what anyone says.

If any of these armchair electronic communiction antenna experts want
to keep debunking it with their idea of the laws of physics without
reading all your theories on it--Well so be it, with their ignorance .
They obviously have thousands of dollars invested in their huge beams
and don't care about the poor guys that have to live in deed restricted
areas, who could greatly benefit from this. It would be great if they
could keep an open mind and just start listening to some of the other
reports that will be coming in from other builders.

Like I said before, I have built many many small and large wire
antennas only to have little to mediocre performance. Your antenna just
blew me away with it's performance.

Even though I am not an antenna expert - I know antenna performance
when I see it. I don't care if it defies the laws of physics or you
have come up with some new technological break through --
it bloody works and that's all there is to it .
I really don't care if these so called experts don't believe us. They
can just keep their ignoramist heads stuck in the sand and keep
studying and memorizing the old formulas in their old physics books
till they are blue in the face.

Thanks , -- Paul VE3UNF

-----------------------------------
John Smith wrote:

Sal M. Onella wrote:
Blasphemy ought to have a point -- and I had the misfortune to open

this on
...

Very sorry you feel that way OM. Because your opinion matters to me, I
have went to the time and expense of setting up a special support
hotline for you. ...
JS


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Old March 1st 07, 11:03 PM
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Default

RoomCap antenna and NEC

There is a large family of antanna simulation programs of NEC
like EZNEC, MMANA, 4NEC2, NEC-2, NEC-4 etc.
These programs can produce excellent results in designing and
optimizing of beams and similar antennas.

Personally, I made very good experience by optimizing the well
known Spiderbeam. The results of the simulation proved to be
fully correct in the practical field tests.

However, there are many cases where the simulation with NEC
programs is failing.
You may obain results indicating efficency of over 100% !
This is not the discovery of a "perpetual motion machine", it is
an error of computer simulation ..., or the results may become
very inaccurate if there are varying diameters, different
dielectricas etc.

The NEC programs are designed primarilly for wire
constructions and can be used for other constructions only
under specific conditions.

Regarding my RoomCap antenna the question was rised many
times, how the NEC simulation would look like.
Here I can say very simply: This construction can not be defined
by the existing NEC programs.
Especially the central element, the Varylink, can not be defined
by NEC. Discussions with the well known NEC expert L. B. Cebik,
W4RNL have revealed, that a way will be searched to include
such elements in later editions of the programs.

This example shows once more, that the usual way of antenna
development with simulation, as is done mostly today, is a
bad way, as finding of new constructions is prevented by
the many limitations of the simulation programs.
The programs are good at schools to show the students
the behaving of changing parameters, but are not the way
of the inventing engineer.

To find new ways and concepts, one depends on the
profound knowledge, the experience, and the mental force
of the engineer, together with experimenting in the field.
The computer is a very helpful tool in many aspects, but
one may not expect much novelties by "experimenting"
with simulation. At least not, until big improvements are
made to these programs.

Felix Meyer HB9ABX
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Old March 3rd 07, 08:57 PM posted to rec.radio.amateur.antenna
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Default RoomCap Antenna

Felix wrote:

...
The computer is a very helpful tool in many aspects, but
one may not expect much novelties by "experimenting"
with simulation. At least not, until big improvements are
made to these programs.

Felix Meyer HB9ABX


All formulas were derived from "real hands-on"
construction/development/experimenting. They will only be correct in
the narrow confines of what has been built before, or closely related
models to these physical antennas upon which the equations/formulas were
derived from.

Duh!


JS
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