Miguel
There are "eyewitness accounts" of all sorts of foolishness.

If you build it perfectly a bazooka will show a decrease in SWR over a very
small range either side of resonance (SWR = 1:1) when compared to a dipole.
This is completely useless except as an academic exercise.

Here's how it works:
The antenna is a parallel-resonant network (the bazooka) in parallel with a
series-resonant network(the dipole).
The parallel resonant (tank circuit) network stores energy and will
oscillate at it's DRIVEN frequency when driven near resonance, so it stores
the energy that would otherwise be reflected as long as it oscillates. Go
too far from resonance and it quits oscillating. This effect manifests
itself at SWR of 1.2:1 or lower. It flattens the SWR curve very near
resonance.
The 2:1 bandwidth is unaffected except by the additional loss of the tank
circuit sitting across the dipole feed point.

What Walter Maxwell showed explicitly is that any increase in SWR bandwidth
is entirely due to loss, if I recall correctly.

So all the trouble of building a bazooka with both legs and the dipole
resonant at exactly the same frequency is a waste of time.
A simple dipole works a bit better and is *MUCH LESS* work and expen$e.

73
H.
NQ5H


"lu6etj" wrote in message
oups.com...

Dear friends:

Thank you very much for your answers.

First of all: I agree with you, but my agreement is inductive, not
experimental because I have not made my homework with that antenna...
..
I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"

But do I think: is it possible that all those friends that are
enthusiastic of the bazooka are affirming foolishness? They say: -With
the bazooka we listen stations that we don't with the plain dipole, and
this affirmatiotn point to a better SNR...

I think that it must have something true behind so many similar
statements. In the radio club of my area they say to have compared one
against another with clearly favorable results to the bazooka.

I thought...: A plain dipole is not a monoband antenna, it is, in fact,
a multiband antenna, it receives all the frequencies. But do let us
imagine a plain dipole that had connected on its terminals a couple
high Q tuned circuits. That system it would be really "monoband"...
then, if we connect such a system to a poor receiver Would not it
improve the reception perhaps?, eliminating by that way possible
saturation sources or intermodulación noises.
Such a system, empirically it would seem a practically "more silent
antenna" and it would explain, perhaps, the some results obtained by
the colleagues. I say this because it is said that the bazooka
possesses a syntony effect that transforms it into a true monoband
device (I am not sure of it).

It is only an arbitrary example of possible alternative explanations
that, without violating the fundamental principles, can be
compatibilized with the experiences of so many colleagues that
sympathize with this antennas(some of which deserve my technical
respect).

I thank all your answers but I continue to the search of some
explanation that endorses all the facts, just as the formidable article
of Walter in reference to its bandwidth...

I am for sure some of you will be able to help me to find a convincing
explanation.

Thank you very much in adavnce

Miguel Ghezzi (LU 6ETJ)

H. Adam Stevens, NQ5H wrote:
I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"

"Their" article? Walt has a ghost writer?


--
73 from Ian GM3SEK

I think he's referring to the Maxwell of Maxwell's Equations.

"Ian White GM3SEK" wrote in message
...
H. Adam Stevens, NQ5H wrote:
I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"

"Their" article? Walt has a ghost writer?


--
73 from Ian GM3SEK

Ian White GM3SEK wrote:
H. Adam Stevens, NQ5H wrote:
I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"

"Their" article? Walt has a ghost writer?

There's a false attribution above, Ian. It should be:

"lu6etj" wrote:
I knew the excellent article of Walter Maxwell, I am a
fan of Maxwell, (both Maxwells) from their famous article
"Another look on reflections"
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Ian White GM3SEK wrote:
H. Adam Stevens, NQ5H wrote:
I knew the excellent article of Walter Maxwell, I am a fan of
Maxwell, (both Maxwells) from their famous article "Another look on
reflections"
"Their" article? Walt has a ghost writer?

There's a false attribution above, Ian. It should be:

"lu6etj" wrote:
I knew the excellent article of Walter Maxwell, I am a
fan of Maxwell, (both Maxwells) from their famous article
"Another look on reflections"

You're right, Cecil - my apologies to all concerned.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Ian White GM3SEK wrote:
H. Adam Stevens, NQ5H wrote:

I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"


"Their" article? Walt has a ghost writer?



It's the royal "their."
73,
Tom Donaly, KA6RUH

Hi Hi...

Don't forget I am argentine, here we speak spanish all the day, it is
my own translation error of possesive case... "their" it is wrong ,
"his" is the correct.- "...from HIS famous article..." R?

References to "both" Mawells, yes, James an Walter..., (thanks Adam)

Miguel
-----------------------

Tom Donaly ha escrito:

Ian White GM3SEK wrote:
H. Adam Stevens, NQ5H wrote:

I knew the excellent article of Walter Maxwell, I am a fan of Maxwell,
(both Maxwells) from their famous article "Another look on reflections"


"Their" article? Walt has a ghost writer?



It's the royal "their."
73,
Tom Donaly, KA6RUH

lu6etj wrote:
Don't forget I am argentine, here we speak spanish all the day, it is
my own translation error of possesive case... "their" it is wrong ,
"his" is the correct.- "...from HIS famous article..." R?

The negative comments occurred because of errors in
the attribution of your posting. It wasn't your fault
so please don't worry about it.

Back to Double Bazookas: It is a well accepted fact that
insulation reduces the precipitation static problem.
So the Double Bazooka reduces the precipitation static
in two ways. 1. DC path between elements, 2. Insulation.
--
73, Cecil http://www.qsl.net/w5dxp

I A B tested a regular low dipole made from number 8 AWG bare wire
against a double bazooka. Even during severe weather there never was a
difference in measureable noise levels.

That's just from a direct observation over a long period of time
between the two antenna types.

There also was no measurable or noticeable difference in signal
strength or bandwidth.

73 Tom

wrote:
I A B tested a regular low dipole made from number 8 AWG bare wire
against a double bazooka. Even during severe weather there never was a
difference in measureable noise levels.

Did you A B test them under precipitation static conditions?
If not, the test was incomplete. There is obviously a charged
particle difference between a bare wire dipole and a double
bazooka. If you weren't testing using charged particles, the
test was just as obviously incomplete.
--
73, Cecil http://www.qsl.net/w5dxp