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Old April 11th 09, 12:49 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

On Apr 10, 6:00*pm, "Dale Parfitt" wrote:
*That antenna was when I used an old parabolic satellite dish which was
unsuitable.
Scanning past antenna papers point to the use of a cone shape similar
to a horn of 2 metres diameter
produces better results. The antenna needs a longer mast so at the
moment I can't compare
F/R. Either way, with the radiator within the reflector envelope it is
difficult to understand what creates
a rearward lobe regardles of scale or frequency of use with respect to
receive. At the moment I see nothing that points away from the
Rutherford particle experiments with foil .ie penetration when at
right angles , deflection at other angles.

As usual Art you are avoiding answering the questions and choose to confuse
the issues
with you own preconceived ideas and terminology. The fact that the feed is
totally within the "reflector envelope" tells you or us nothing about
sidelobes and edge taper.
I really don't think you want answers, but I'll try once mo
1. What frequency
2. What is the dish diameter
3. What is the dish focal length to diameter ratio (F/D)

Dale W4OP


I am not avoiding questions, just those that appear irrelevant, but
here goes Anything to make you happy, this should be interesting how
you use these answers with respect to the posted question

1 160 metres upto 2 metres, tunable

2 2 metres

3 Doesn't have a focal length, it is an end fed ( series connection)
helix antenna.

At least to the best of my knowledge which is why I posed the question
Hopefully we will all stay on subject and not get side tracked. I will
leave it to others to respond to Richard when they determine what he
is talking about.
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Old April 11th 09, 01:19 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

On Fri, 10 Apr 2009 16:49:31 -0700 (PDT), Art Unwin
wrote:

1. What frequency
2. What is the dish diameter
3. What is the dish focal length to diameter ratio (F/D)


I am not avoiding questions, just those that appear irrelevant,


20 postings to get to the point (not unanticipated, however) which Art
calls "irrelevant."

As for those answers?
1 160 metres upto 2 metres, tunable


2 2 metres

Hence the wholesale disregard for first principles in size vs.
wavelength. Elementary analysis need not go any further when failure
is so obviously designed in.

3 Doesn't have a focal length, it is an end fed ( series connection)
helix antenna.

-Well, maybe not obvious to everyone.-

But why don't we chalk this design up to S U C C E S S and call it a
thread? If this bier gets anymore wreaths tossed onto it, it will
kill the pallbearers.

73's
Richard Clark, KB7QHC
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Old April 11th 09, 02:01 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

On Apr 10, 7:19*pm, Richard Clark wrote:
On Fri, 10 Apr 2009 16:49:31 -0700 (PDT), Art Unwin

wrote:
1. What frequency
2. What is the dish diameter
3. What is the dish focal length to diameter ratio (F/D)


I am not avoiding questions, just those that appear irrelevant,


20 postings to get to the point (not unanticipated, however) which Art
calls "irrelevant."

As for those answers?

1 160 metres upto 2 metres, tunable
2 2 metres


Hence the wholesale disregard for first principles in size vs.
wavelength. *Elementary analysis need not go any further when failure
is so obviously designed in. *

3 Doesn't have a focal length, it is an end fed ( series connection)
helix antenna.


-Well, maybe not obvious to everyone.-

But why don't we chalk this design up to S U C C E S S and call it a
thread? *If this bier gets anymore wreaths tossed onto it, it will
kill the pallbearers.

73's
Richard Clark, KB7QHC


The posting is about dishes not antennas. I have not read about a dish
that does not emit signals to the rear. Now I have built one and find
to my surprize that it does accept signals from the rear ! All very
simple, the radiator is resting at the bottom of a cone and the top of
the radiator does not stick out beyond the reflector. Since you do not
know what you are talking about and intent is to disrupt this thread
why on earth are you muttering about nothing at length? Simple
question has been posed and obviously you do not know the answers that
antenna engineering knowledge would provide as you are not an engineer
but a actor or actress by day and by night. My question remains
unanswered after all these posts.How do signals arrive or depart from
the rear of a dish or horn? We all know that you don't know the answer
but there are qualified engineers in this group who possibly doand
willing to share.
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Old April 11th 09, 02:13 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

The posting is about dishes not antennas. I have not read about a dish
that does not emit signals to the rear. Now I have built one and find
to my surprize that it does accept signals from the rear ! All very
simple, the radiator is resting at the bottom of a cone and the top of
the radiator does not stick out beyond the reflector. Since you do not
know what you are talking about and intent is to disrupt this thread
why on earth are you muttering about nothing at length? Simple
question has been posed and obviously you do not know the answers that
antenna engineering knowledge would provide as you are not an engineer
but a actor or actress by day and by night. My question remains
unanswered after all these posts.How do signals arrive or depart from
the rear of a dish or horn? We all know that you don't know the answer
but there are qualified engineers in this group who possibly doand
willing to share.

Your antenna has nothing to do with dish antennas, bu rather plane
reflectors (of which yours is way too small as Richard pointed out).
I know we cannot change your opinion or teach you anything- so I am out of
here.

Dale W4OP


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Old April 11th 09, 03:17 AM posted to rec.radio.amateur.antenna
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On Apr 10, 8:13*pm, "Dale Parfitt" wrote:
*The posting is about dishes not antennas. I have not read about a dish
that does not emit signals to the rear. Now I have built one and find
to my surprize that it does accept signals from the rear ! All very
simple, the radiator is resting at the bottom of a cone and the top of
the radiator does not stick out beyond the reflector. Since you do not
know what you are talking about and intent is to disrupt this thread
why on earth are you muttering about nothing at length? Simple
question has been posed and obviously you do not know the answers that
antenna engineering knowledge would provide as you are not an engineer
but a actor or actress by day and by night. *My question remains
unanswered after all these posts.How do signals arrive or depart from
the rear of a dish or horn? We all know that you don't know the answer
but there are qualified engineers in this group who possibly doand
willing to share.

Your antenna has nothing to do with dish antennas, bu rather plane
reflectors (of which yours is way too small as Richard pointed out).
I know we cannot change your opinion or teach you anything- so I am out of
here.

Dale W4OP


Dale, my response above was with respect to Richard not you, but I did
know you would run eventually. Study the math of Maxwell and Gauss
before you decide to take up teaching.


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Old April 11th 09, 02:45 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

Art Unwin wrote:

The posting is about dishes not antennas. I have not read about a dish
that does not emit signals to the rear. Now I have built one and find
to my surprize that it does accept signals from the rear ! All very
simple, the radiator is resting at the bottom of a cone and the top of
the radiator does not stick out beyond the reflector. Since you do not


Well, to start with Art, a cone reflector doesn't meet the definition of
a dish antenna.

I'm sorry, but they just aren't the same thing.

I surprizzzed you missed the difference.

tom
K0TAR
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Old April 11th 09, 02:49 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

Tom Ring wrote:
Art Unwin wrote:

snip

tom
K0TAR


Jimmie

I just couldn't resist, just this once.

tom
K0TAR
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Old April 11th 09, 03:30 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

On Apr 10, 8:45*pm, Tom Ring wrote:
Art Unwin wrote:

The posting is about dishes not antennas. I have not read about a dish
that does not emit signals to the rear. Now I have built one and find
to my surprize that it does accept signals from the rear ! All very
simple, the radiator is resting at the bottom of a cone and the top of
the radiator does not stick out beyond the reflector. Since you do not


Well, to start with Art, a cone reflector doesn't meet the definition of
a dish antenna.

I'm sorry, but they just aren't the same thing.

I surprizzzed you missed the difference.

tom
K0TAR


Tom
I asked the question as I am not personly knowledgable about dish
style reflectors.
I do read a lot and I read a paper once where it was found that a cone
shaped reflector produced increased gain when used with a helix
antenna, so I made one to try it out. Personaly I see it more as a
horn and not as a dish with a radiator at a phase control difference
from the reflector? Either way I do not understand how that I can hear
signals to the rear if the reflector envelope encloses the radiator
thus the question. Note that a helix radiates differently from the
normal dish radiator such that phasing does not enter the design which
is why you see planar dishes or "cups".
Thus questions with respect to reflector diameter are not
pertinentwhen the radiator is enclosed.
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Old April 11th 09, 03:51 AM posted to rec.radio.amateur.antenna
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Default Dish reflector

Art Unwin wrote:\
Tom
I asked the question as I am not personly knowledgable about dish
style reflectors.
I do read a lot and I read a paper once where it was found that a cone
shaped reflector produced increased gain when used with a helix
antenna, so I made one to try it out. Personaly I see it more as a
horn and not as a dish with a radiator at a phase control difference
from the reflector? Either way I do not understand how that I can hear
signals to the rear if the reflector envelope encloses the radiator
thus the question. Note that a helix radiates differently from the
normal dish radiator such that phasing does not enter the design which
is why you see planar dishes or "cups".
Thus questions with respect to reflector diameter are not
pertinentwhen the radiator is enclosed.


He is _awfully_ funny, isn't he?

tom
K0TAR
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Old April 11th 09, 08:49 AM posted to rec.radio.amateur.antenna
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I don't see Art's postings except as they're quoted by others. But from
what I'm seeing here, it looks like he's done a great experiment which
graphically shows that radio waves don't act like particles. More
experiments along this line weren't really necessary, since it's been
known at least since Hertz's experiments in the 19th century. And anyone
who took high school physics and watched the ripples in the ripple tank
should be able to immediately predict what Art is describing. But I
suppose the experiment and its results might prove enlightening for
those readers who didn't take high school physics and who are nearly
completely unacquainted with electromagnetics.

Roy Lewallen, W7EL


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