| Topic: |
Science > Physics |
| User: |
"Randy Poe" |
| Date: |
07 Dec 2006 01:20:59 PM |
| Object: |
Antennas 101 for Androcles |
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss. Rather than continue to clutter those
threads, let me put the relevant information into one place.
Engineers characterize every antenna by its gain, which
relates the power to omnidirectional power. A perfectly
omnidirectional antenna has a gain of 1, or 0 dB. Gain is
related to directivity. An antenna with a gain of 30 dB
(a factor of 1000) is highly directional. If receiving, it
gets its energy from about 1/1000-th of the sphere. If
transmitting, it is putting its energy out in 1/1000 of the
sphere and therefore the intensity is 1000 times higher
in that direction than if it tried to spread the energy in
all directions equally.
Good parabolic antennas have gains in the neighborhood
of 50 dB. Aside from shape, the most important parameter
affecting gain is D/lambda, the ratio of diameter to
wavelength. If the antenna is not circular, it is some other
characteristic length/lambda. If you take a given antenna
shape and double its size, but then double the wavelength,
you'll get the same gain.
The area of a sphere grows as r^2 where r is the radius
of the sphere. An antenna like Cassini's with a gain of
50 dB is transmitting its energy into 1/100000 of the
sphere. 1/100000 of a thing growing as r^2 is still growing
as r^2.
Now if you do simple ray tracing, it looks like every ray
leaving the focus and bouncing off a parabolic mirror should
exit parallel. So why is there a beamwidth?
First of all, it is because light is a wave, and the reflection
and focusing of waves is not so simple as ray-tracing. The
pattern from a parabolic antenna is very similar to the diffraction
pattern from a small circular hole, a pattern which also has
angular width ~ D/lambda.
Secondly, the focus is a point, and real antenna feeds
have a volume, so the energy is coming from places
that aren't exactly at the focus.
Third, the shape will never be exactly parabolic. In real
life, there are always variations.
- Randy
.
|
|
| User: "Sorcerer" |
|
| Title: Parabolas for Blind Poe. |
07 Dec 2006 03:02:52 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| Androcles is currently cluttering multiple threads with his
| assertion that beams from parabolic antennas experience no
| 1/r^2 free-space loss.=20
Correct, I am. =20
Parabolic antennae (note spelling) are not omnidirectional
antennae. If they were headlights on cars would be useless.
What inverse square law, fuckhead?
Androcles
.
|
|
|
| User: "Randy Poe" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 03:07:38 PM |
|
|
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| Androcles is currently cluttering multiple threads with his
| assertion that beams from parabolic antennas experience no
| 1/r^2 free-space loss.
Correct, I am.
Parabolic antennae (note spelling) are not omnidirectional
antennae.
No they aren't. I agree. They have very small angular width.
Their energy is radiated into a circular patch of very small
angular extent. It is the same angle at every distance.
Is a 1 degree arc the same length at 10 m and 100 m?
If they were headlights on cars would be useless.
Are headlights at 10 m just as bright as headlights
at 1 km?
What inverse square law, fuckhead?
The one that says that a circular patch which is X degrees wide
has an area of pi*r^2*(X*pi/180)^2.
- Randy
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 05:37:19 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
|=20
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae.
|=20
| No they aren't. I agree. They have very small angular width.
| Their energy is radiated into a circular patch of very small
| angular extent. It is the same angle at every distance.
|=20
| Is a 1 degree arc the same length at 10 m and 100 m?
Don't ask me questions, Poe, answer mine first.
You really want to advertise your ignorance in every thread, don't you?
Blind Poe is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience=20
1/r^2 free-space loss, the fucking troll.
What inverse square law, fuckwit?
.
|
|
|
| User: "Helmut Wabnig .... --. .- -... -. .. .-- @ .- --- -. DOT .- -" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 02:35:11 AM |
|
|
On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
<Headmaster@hogwarts.physics_e> wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
|
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae.
|
| No they aren't. I agree. They have very small angular width.
| Their energy is radiated into a circular patch of very small
| angular extent. It is the same angle at every distance.
|
| Is a 1 degree arc the same length at 10 m and 100 m?
Don't ask me questions, Poe, answer mine first.
You really want to advertise your ignorance in every thread, don't you?
Blind Poe is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience
1/r^2 free-space loss, the fucking troll.
What inverse square law, fuckwit?
Poe, do it, say it, post it, to end it,
http://en.wikipedia.org/wiki/Friis_Transmission_Equation
w.
.
|
|
|
| User: "Randy Poe" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 11:11:54 AM |
|
|
Helmut Wabnig wrote:
On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
<Headmaster@hogwarts.physics_e> wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
|
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae.
|
| No they aren't. I agree. They have very small angular width.
| Their energy is radiated into a circular patch of very small
| angular extent. It is the same angle at every distance.
|
| Is a 1 degree arc the same length at 10 m and 100 m?
Don't ask me questions, Poe, answer mine first.
You really want to advertise your ignorance in every thread, don't you?
Blind Poe is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience
1/r^2 free-space loss, the fucking troll.
What inverse square law, fuckwit?
Poe, do it, say it, post it, to end it,
http://en.wikipedia.org/wiki/Friis_Transmission_Equation
You don't know Androcles. I have calmly posted the inverse
square law many times after this silly little tag line. Guess
what his response is?
"What inverse square law, [profanity]?"
"[Explanation of inverse square law for narrow beams]"
"What inverse square law, [profanity]?"
"[Explanation of inverse square law for narrow beams]"
etc.
Anyway, for "Professional Engineer" Androcles, here is
a chapter from an ENGINEERING text, referencing the
Navy's "Radar System ENGINEERING Handbook", doing
some ENGINEERING calculations of the actual amount of
beam spreading from a parabolic dish.
http://www.qsl.net/n1bwt/app-6a.pdf
All the patterns have sidelobes, an issue I've completely
ignored in this elementary discussion. That is a significant
amount of energy emitted at undesired directions far
away from the main beam.
But in addition, all the patterns show a spread of a few
degrees in the main beam. And of course a pattern which is a
few degrees wide in all directions spreads in area as r^2.
- Randy
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 12:45:43 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165597914.331522.19240@73g2000cwn.googlegroups.com...
|=20
| Helmut Wabnig wrote:
| > On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
| > <Headmaster@hogwarts.physics_e> wrote:
| >
| > >
| > >"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
| > >|
| > >| Sorcerer wrote:
| > >| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > >| > | Androcles is currently cluttering multiple threads with his
| > >| > | assertion that beams from parabolic antennas experience no
| > >| > | 1/r^2 free-space loss.
| > >| >
| > >| > Correct, I am.
| > >| > Parabolic antennae (note spelling) are not omnidirectional
| > >| > antennae.
| > >|
| > >| No they aren't. I agree. They have very small angular width.
| > >| Their energy is radiated into a circular patch of very small
| > >| angular extent. It is the same angle at every distance.
| > >|
| > >| Is a 1 degree arc the same length at 10 m and 100 m?
| > >
| > >Don't ask me questions, Poe, answer mine first.
| > >You really want to advertise your ignorance in every thread, don't =
you?
| > >
| > >Blind Poe is currently cluttering multiple threads with his
| > >assertion that beams from parabolic antennas experience
| > >1/r^2 free-space loss, the fucking troll.
| > >What inverse square law, fuckwit?
| > >
| > Poe, do it, say it, post it, to end it,
| >
| > http://en.wikipedia.org/wiki/Friis_Transmission_Equation
|=20
| You don't know Androcles. I have calmly posted the inverse
| square law many times after this silly little tag line. Guess
| what his response is?
Here's the final response:
You want a recap, Poe? Ok.
Donna:
PS RE Sue's comments: Doesn't the inverse square law for the
attenuation only reign true in a vacuum??
Blind Poe:=20
| So far as I know, it's used in air also, but there are additional
| losses
| that have to be accounted for.
Androcles:
http://saturn.jpl.nasa.gov/spacecraft/images/spacecraft-litho.jpg
What inverse square law? (no profanity)
Blind Poe:=20
(news:1165406758.051828.94600@n67g2000cwd.googlegroups.com)
| The one that says signal to noise decreases as 1/R^2, or as
| 20*log10(R) in dB.
| Was that picture supposed to be relevant?
Androcles:=20
That big umbrella on the top isn't for raindrops, idiot. (first insult)
Cassini doesn't radiate is all directions, it's transmitter isn't =
powerful
enough to be heard if the signal wasn't beamed.
What inverse square law? (no profanity)
Blind Poe:=20
(news:1165424060.794583.24150@79g2000cws.googlegroups.com)
The inverse square law that says the area covered by a
constant solid angle increases as the square of the radius.
The one that says the area of the base of a conical
pyramid increases as the square of the height.
Blind Poe:
(news:1165457536.255421.10020@n67g2000cwd.googlegroups.com)
So you not only disbelieve in the inverse square law, but in
absorption spectra?
Blind Poe:=20
(news:1165512324.621977.36760@l12g2000cwl.googlegroups.com)
(Androcles thinks parabolic antennas produce beams which
do not spread with distance)
Blind Poe:
(news:1165511733.596794.227050@j72g2000cwa.googlegroups.com)
You really want to advertise your ignorance in every thread, don't you?
(Androcles believes beams transmitted by parabolic antennas
do not spread and there is no 1/r^2 free-space path loss).
Blind Poe:=20
(news:1165512455.347383.65400@79g2000cws.googlegroups.com)
(Androcles wants everyone in every thread to know he believes
parabolic antennas produce beams that do not spread, and
that do not obey the inverse square law. I'm happy to help
spread his message.)
Blind Poe:=20
(news:1165519259.245771.29120@16g2000cwy.googlegroups.com)
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss.=20
Blind Poe:=20
(news:1165526906.374730.7090@l12g2000cwl.googlegroups.com)
| > The one that says that a circular patch which is X degrees wide
| > has an area of pi*r^2*(X*pi/180)^2.
|=20
| Sorry, that's off by a factor of 4. Radius of a circular
| patch X degrees in diameter is r*X*pi/360.
|=20
| A =3D [pi*(X*pi/360)^2] * r^2
|=20
| Androcles seems to think the only two possibilities are either
| no spread at all, or omnidirectional spread.=20
Androcles:
I did not say that, you stupid LYING *****!
(end recap)
Now it's over, Blind Poe should have said "I don't know, I'll ask."
But Blind Poe is a fucking ignorant LYING troll who tried to *****
his way out of it after sneering at Androcles and misleading Donna,
the fucking *****. Isn't he, Wabnigger? Isn't he, Poe?
It is over,=20
http://en.wikipedia.org/wiki/Friis_Transmission_Equation
but not forgotten.=20
Keep digging, Poe. I'll bury you, you arrogant ***** and stupid *****!
.
|
|
|
| User: "Randy Poe" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 12:57:20 PM |
|
|
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165597914.331522.19240@73g2000cwn.googlegroups.com...
|
| Helmut Wabnig wrote:
| > On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
| > <Headmaster@hogwarts.physics_e> wrote:
| >
| > >
| > >"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
| > >|
| > >| Sorcerer wrote:
| > >| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > >| > | Androcles is currently cluttering multiple threads with his
| > >| > | assertion that beams from parabolic antennas experience no
| > >| > | 1/r^2 free-space loss.
| > >| >
| > >| > Correct, I am.
| > >| > Parabolic antennae (note spelling) are not omnidirectional
| > >| > antennae.
| > >|
| > >| No they aren't. I agree. They have very small angular width.
| > >| Their energy is radiated into a circular patch of very small
| > >| angular extent. It is the same angle at every distance.
| > >|
| > >| Is a 1 degree arc the same length at 10 m and 100 m?
| > >
| > >Don't ask me questions, Poe, answer mine first.
| > >You really want to advertise your ignorance in every thread, don't you?
| > >
| > >Blind Poe is currently cluttering multiple threads with his
| > >assertion that beams from parabolic antennas experience
| > >1/r^2 free-space loss, the fucking troll.
| > >What inverse square law, fuckwit?
| > >
| > Poe, do it, say it, post it, to end it,
| >
| > http://en.wikipedia.org/wiki/Friis_Transmission_Equation
|
| You don't know Androcles. I have calmly posted the inverse
| square law many times after this silly little tag line. Guess
| what his response is?
Here's the final response:
You want a recap, Poe? Ok.
Donna:
PS RE Sue's comments: Doesn't the inverse square law for the
attenuation only reign true in a vacuum??
Blind Poe:
| So far as I know, it's used in air also, but there are additional
| losses
| that have to be accounted for.
Androcles:
http://saturn.jpl.nasa.gov/spacecraft/images/spacecraft-litho.jpg
What inverse square law? (no profanity)
Blind Poe:
(news:1165406758.051828.94600@n67g2000cwd.googlegroups.com)
| The one that says signal to noise decreases as 1/R^2, or as
| 20*log10(R) in dB.
| Was that picture supposed to be relevant?
Androcles:
That big umbrella on the top isn't for raindrops, idiot. (first insult)
Cassini doesn't radiate is all directions, it's transmitter isn't powerful
enough to be heard if the signal wasn't beamed.
What inverse square law? (no profanity)
Blind Poe:
(news:1165424060.794583.24150@79g2000cws.googlegroups.com)
The inverse square law that says the area covered by a
constant solid angle increases as the square of the radius.
The one that says the area of the base of a conical
pyramid increases as the square of the height.
Blind Poe:
(news:1165457536.255421.10020@n67g2000cwd.googlegroups.com)
So you not only disbelieve in the inverse square law, but in
absorption spectra?
Blind Poe:
(news:1165512324.621977.36760@l12g2000cwl.googlegroups.com)
(Androcles thinks parabolic antennas produce beams which
do not spread with distance)
Blind Poe:
(news:1165511733.596794.227050@j72g2000cwa.googlegroups.com)
You really want to advertise your ignorance in every thread, don't you?
(Androcles believes beams transmitted by parabolic antennas
do not spread and there is no 1/r^2 free-space path loss).
Blind Poe:
(news:1165512455.347383.65400@79g2000cws.googlegroups.com)
(Androcles wants everyone in every thread to know he believes
parabolic antennas produce beams that do not spread, and
that do not obey the inverse square law. I'm happy to help
spread his message.)
Blind Poe:
(news:1165519259.245771.29120@16g2000cwy.googlegroups.com)
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss.
Blind Poe:
(news:1165526906.374730.7090@l12g2000cwl.googlegroups.com)
| > The one that says that a circular patch which is X degrees wide
| > has an area of pi*r^2*(X*pi/180)^2.
|
| Sorry, that's off by a factor of 4. Radius of a circular
| patch X degrees in diameter is r*X*pi/360.
|
| A = [pi*(X*pi/360)^2] * r^2
|
| Androcles seems to think the only two possibilities are either
| no spread at all, or omnidirectional spread.
Androcles:
I did not say that, you stupid LYING *****!
(end recap)
Now it's over, Blind Poe should have said "I don't know, I'll ask."
What didn't I know? I work with this stuff every day. I work
with engineers who are expert in this stuff. The inverse
square law is embedded in the DNA around here. I've
never run into a person before you who didn't believe in it.
Fortunately, the people who actually design the RF systems
know to take it into account in calculation of losses BECAUSE
IT'S ON PAGE ONE OF EVERY FRIGGING RF TEXT!
But Blind Poe is a fucking ignorant LYING troll who tried to *****
his way out of it after sneering at Androcles and misleading Donna,
the fucking *****. Isn't he, Wabnigger? Isn't he, Poe?
It is over,
http://en.wikipedia.org/wiki/Friis_Transmission_Equation
but not forgotten.
Keep digging, Poe. I'll bury you, you arrogant ***** and stupid *****!
Will you? Are you aware that link says that the 1/R^2 free-space
loss is valid for satellite communications, which use parabolic
antennas?
- Randy
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 01:30:50 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165604239.939255.156870@80g2000cwy.googlegroups.com...
|=20
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165597914.331522.19240@73g2000cwn.googlegroups.com...
| > |
| > | Helmut Wabnig wrote:
| > | > On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
| > | > <Headmaster@hogwarts.physics_e> wrote:
| > | >
| > | > >
| > | > >"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
| > | > >|
| > | > >| Sorcerer wrote:
| > | > >| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | > >| > | Androcles is currently cluttering multiple threads with =
his
| > | > >| > | assertion that beams from parabolic antennas experience =
no
| > | > >| > | 1/r^2 free-space loss.
| > | > >| >
| > | > >| > Correct, I am.
| > | > >| > Parabolic antennae (note spelling) are not omnidirectional
| > | > >| > antennae.
| > | > >|
| > | > >| No they aren't. I agree. They have very small angular width.
| > | > >| Their energy is radiated into a circular patch of very small
| > | > >| angular extent. It is the same angle at every distance.
| > | > >|
| > | > >| Is a 1 degree arc the same length at 10 m and 100 m?
| > | > >
| > | > >Don't ask me questions, Poe, answer mine first.
| > | > >You really want to advertise your ignorance in every thread, =
don't you?
| > | > >
| > | > >Blind Poe is currently cluttering multiple threads with his
| > | > >assertion that beams from parabolic antennas experience
| > | > >1/r^2 free-space loss, the fucking troll.
| > | > >What inverse square law, fuckwit?
| > | > >
| > | > Poe, do it, say it, post it, to end it,
| > | >
| > | > http://en.wikipedia.org/wiki/Friis_Transmission_Equation
| > |
| > | You don't know Androcles. I have calmly posted the inverse
| > | square law many times after this silly little tag line. Guess
| > | what his response is?
| >
| > Here's the final response:
| > You want a recap, Poe? Ok.
| >
| >
| > Donna:
| > PS RE Sue's comments: Doesn't the inverse square law for the
| > attenuation only reign true in a vacuum??
| >
| > Blind Poe:
| > | So far as I know, it's used in air also, but there are additional
| > | losses
| > | that have to be accounted for.
| >
| > Androcles:
| > http://saturn.jpl.nasa.gov/spacecraft/images/spacecraft-litho.jpg
| > What inverse square law? (no profanity)
| >
| > Blind Poe:
| > (news:1165406758.051828.94600@n67g2000cwd.googlegroups.com)
| > | The one that says signal to noise decreases as 1/R^2, or as
| > | 20*log10(R) in dB.
| >
| > | Was that picture supposed to be relevant?
| >
| > Androcles:
| > That big umbrella on the top isn't for raindrops, idiot. (first =
insult)
| > Cassini doesn't radiate is all directions, it's transmitter isn't =
powerful
| > enough to be heard if the signal wasn't beamed.
| >
| > What inverse square law? (no profanity)
| >
| > Blind Poe:
| > (news:1165424060.794583.24150@79g2000cws.googlegroups.com)
| > The inverse square law that says the area covered by a
| > constant solid angle increases as the square of the radius.
| > The one that says the area of the base of a conical
| > pyramid increases as the square of the height.
| >
| > Blind Poe:
| > (news:1165457536.255421.10020@n67g2000cwd.googlegroups.com)
| > So you not only disbelieve in the inverse square law, but in
| > absorption spectra?
| >
| > Blind Poe:
| > (news:1165512324.621977.36760@l12g2000cwl.googlegroups.com)
| >
| > (Androcles thinks parabolic antennas produce beams which
| > do not spread with distance)
| >
| > Blind Poe:
| > (news:1165511733.596794.227050@j72g2000cwa.googlegroups.com)
| >
| > You really want to advertise your ignorance in every thread, don't =
you?
| > (Androcles believes beams transmitted by parabolic antennas
| > do not spread and there is no 1/r^2 free-space path loss).
| >
| > Blind Poe:
| > (news:1165512455.347383.65400@79g2000cws.googlegroups.com)
| > (Androcles wants everyone in every thread to know he believes
| > parabolic antennas produce beams that do not spread, and
| > that do not obey the inverse square law. I'm happy to help
| > spread his message.)
| >
| > Blind Poe:
| > (news:1165519259.245771.29120@16g2000cwy.googlegroups.com)
| > Androcles is currently cluttering multiple threads with his
| > assertion that beams from parabolic antennas experience no
| > 1/r^2 free-space loss.
| >
| >
| > Blind Poe:
| > (news:1165526906.374730.7090@l12g2000cwl.googlegroups.com)
| >
| > | > The one that says that a circular patch which is X degrees wide
| > | > has an area of pi*r^2*(X*pi/180)^2.
| > |
| > | Sorry, that's off by a factor of 4. Radius of a circular
| > | patch X degrees in diameter is r*X*pi/360.
| > |
| > | A =3D [pi*(X*pi/360)^2] * r^2
| > |
| > | Androcles seems to think the only two possibilities are either
| > | no spread at all, or omnidirectional spread.
| >
| > Androcles:
| > I did not say that, you stupid LYING *****!
| >
| >
| > (end recap)
| >
| > Now it's over, Blind Poe should have said "I don't know, I'll ask."
|=20
| What didn't I know? I work with this stuff every day. I work
| with engineers who are expert in this stuff. The inverse
| square law is embedded in the DNA around here. I've
| never run into a person before you who didn't believe in it.
|=20
| Fortunately, the people who actually design the RF systems
| know to take it into account in calculation of losses BECAUSE
| IT'S ON PAGE ONE OF EVERY FRIGGING RF TEXT!
|=20
| > But Blind Poe is a fucking ignorant LYING troll who tried to =
*****
| > his way out of it after sneering at Androcles and misleading Donna,
| > the fucking *****. Isn't he, Wabnigger? Isn't he, Poe?
| > It is over,
| > http://en.wikipedia.org/wiki/Friis_Transmission_Equation
| > but not forgotten.
| >
| > Keep digging, Poe. I'll bury you, you arrogant ***** and stupid =
*****!
|=20
| Will you? Are you aware that link says that the 1/R^2 free-space
| loss is valid for satellite communications, which use parabolic
| antennas?
=
http://wildwoodsurvival.com/survival/fire/magnifier/Magnifyingglassfire17=
41.jpg
Keep digging, Poe. I'll bury you, you arrogant ***** and stupid *****!
| Helmut Wabnig wrote:
| > On Thu, 07 Dec 2006 23:37:19 GMT, "Sorcerer"
| > <Headmaster@hogwarts.physics_e> wrote:
| >
| > >
| > >"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165525658.428880.259130@l12g2000cwl.googlegroups.com...
| > >|
| > >| Sorcerer wrote:
| > >| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > >| > | Androcles is currently cluttering multiple threads with his
| > >| > | assertion that beams from parabolic antennas experience no
| > >| > | 1/r^2 free-space loss.
| > >| >
| > >| > Correct, I am.
| > >| > Parabolic antennae (note spelling) are not omnidirectional
| > >| > antennae.
| > >|
| > >| No they aren't. I agree. They have very small angular width.
| > >| Their energy is radiated into a circular patch of very small
| > >| angular extent. It is the same angle at every distance.
| > >|
| > >| Is a 1 degree arc the same length at 10 m and 100 m?
| > >
| > >Don't ask me questions, Poe, answer mine first.
| > >You really want to advertise your ignorance in every thread, don't =
you?
| > >
| > >Blind Poe is currently cluttering multiple threads with his
| > >assertion that beams from parabolic antennas experience
| > >1/r^2 free-space loss, the fucking troll.
| > >What inverse square law, fuckwit?
| > >
| > Poe, do it, say it, post it, to end it,
| >
| > http://en.wikipedia.org/wiki/Friis_Transmission_Equation
|=20
| You don't know Androcles. I have calmly posted the inverse
| square law many times after this silly little tag line. Guess
| what his response is?
Here's the final response:
You want a recap, Poe? Ok.
Donna:
PS RE Sue's comments: Doesn't the inverse square law for the
attenuation only reign true in a vacuum??
Blind Poe:=20
| So far as I know, it's used in air also, but there are additional
| losses
| that have to be accounted for.
Androcles:
http://saturn.jpl.nasa.gov/spacecraft/images/spacecraft-litho.jpg
What inverse square law? (no profanity)
Blind Poe:=20
(news:1165406758.051828.94600@n67g2000cwd.googlegroups.com)
| The one that says signal to noise decreases as 1/R^2, or as
| 20*log10(R) in dB.
| Was that picture supposed to be relevant?
Androcles:=20
That big umbrella on the top isn't for raindrops, idiot. (first insult)
Cassini doesn't radiate is all directions, it's transmitter isn't =
powerful
enough to be heard if the signal wasn't beamed.
What inverse square law? (no profanity)
Blind Poe:=20
(news:1165424060.794583.24150@79g2000cws.googlegroups.com)
The inverse square law that says the area covered by a
constant solid angle increases as the square of the radius.
The one that says the area of the base of a conical
pyramid increases as the square of the height.
Androcles:
Now it's over, Blind Poe should have said "I don't know, I'll ask."
But Blind Poe is a fucking ignorant LYING troll who tried to *****
his way out of it after sneering at Androcles and misleading Donna,
the fucking *****. Isn't he, Wabnigger? Isn't he, Poe?
It is over, but not forgotten.=20
Androcles
http://en.wikipedia.org/wiki/Friis_Transmission_Equation
.
|
|
|
|
|
|
|
|
| User: "Autymn D. C." |
|
| Title: Re: Parabolas for Blind Poe. |
09 Dec 2006 02:08:08 AM |
|
|
Sorcerer wrote:
Don't ask me questions, Poe, answer mine first.
You really want to advertise your ignorance in every thread, don't you?
Blind Poe is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience
1/r^2 free-space loss, the fucking troll.
What inverse square law, fuckwit?
As Sorserer cretin likely blockd my posts, someone tell him about
Coulomb's law.
.
|
|
|
|
|
| User: "Randy Poe" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 03:28:26 PM |
|
|
Randy Poe wrote:
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| Androcles is currently cluttering multiple threads with his
| assertion that beams from parabolic antennas experience no
| 1/r^2 free-space loss.
Correct, I am.
Parabolic antennae (note spelling) are not omnidirectional
antennae.
No they aren't. I agree. They have very small angular width.
Their energy is radiated into a circular patch of very small
angular extent. It is the same angle at every distance.
Is a 1 degree arc the same length at 10 m and 100 m?
If they were headlights on cars would be useless.
Are headlights at 10 m just as bright as headlights
at 1 km?
What inverse square law, fuckhead?
The one that says that a circular patch which is X degrees wide
has an area of pi*r^2*(X*pi/180)^2.
Sorry, that's off by a factor of 4. Radius of a circular
patch X degrees in diameter is r*X*pi/360.
A = [pi*(X*pi/360)^2] * r^2
Androcles seems to think the only two possibilities are either
no spread at all, or omnidirectional spread. There are other
possibilities, such as a beam which is 1 degree wide. Such
a beam increases in area proportional to r^2, but it isn't
omnidirectional.
- Randy
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 05:57:21 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165526906.374730.7090@l12g2000cwl.googlegroups.com...
|=20
| Randy Poe wrote:
| > Sorcerer wrote:
| > > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > > | Androcles is currently cluttering multiple threads with his
| > > | assertion that beams from parabolic antennas experience no
| > > | 1/r^2 free-space loss.
| > >
| > > Correct, I am.
| > > Parabolic antennae (note spelling) are not omnidirectional
| > > antennae.
| >
| > No they aren't. I agree. They have very small angular width.
| > Their energy is radiated into a circular patch of very small
| > angular extent. It is the same angle at every distance.
| >
| > Is a 1 degree arc the same length at 10 m and 100 m?
| >
| > > If they were headlights on cars would be useless.
| >
| > Are headlights at 10 m just as bright as headlights
| > at 1 km?
| >
| > > What inverse square law, fuckhead?
| >
| > The one that says that a circular patch which is X degrees wide
| > has an area of pi*r^2*(X*pi/180)^2.
|=20
| Sorry, that's off by a factor of 4. Radius of a circular
| patch X degrees in diameter is r*X*pi/360.
|=20
| A =3D [pi*(X*pi/360)^2] * r^2
|=20
| Androcles seems to think the only two possibilities are either
| no spread at all, or omnidirectional spread.=20
I did not say that, you stupid LYING *****!
| There are other
| possibilities, such as a beam which is 1 degree wide. Such
| a beam increases in area proportional to r^2, but it isn't
| omnidirectional.
Ah... "OTHER POSSIBILITIES". "NOT OMNIDIRECTIONAL".
How true. =20
Proportional, Blind Poe? WHAT FUCKING PROPORTION?=20
1/r^2, 2/r^2, r/r^2, r^2/r^2, 1/1, other?=20
What inverse square law?
That was the question I asked you, STOOPID *****.
.
|
|
|
| User: "Randy Poe" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 10:56:41 PM |
|
|
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165526906.374730.7090@l12g2000cwl.googlegroups.com...
|
| Randy Poe wrote:
| > Sorcerer wrote:
| > > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > > | Androcles is currently cluttering multiple threads with his
| > > | assertion that beams from parabolic antennas experience no
| > > | 1/r^2 free-space loss.
| > >
| > > Correct, I am.
| > > Parabolic antennae (note spelling) are not omnidirectional
| > > antennae.
| >
| > No they aren't. I agree. They have very small angular width.
| > Their energy is radiated into a circular patch of very small
| > angular extent. It is the same angle at every distance.
| >
| > Is a 1 degree arc the same length at 10 m and 100 m?
| >
| > > If they were headlights on cars would be useless.
| >
| > Are headlights at 10 m just as bright as headlights
| > at 1 km?
| >
| > > What inverse square law, fuckhead?
| >
| > The one that says that a circular patch which is X degrees wide
| > has an area of pi*r^2*(X*pi/180)^2.
|
| Sorry, that's off by a factor of 4. Radius of a circular
| patch X degrees in diameter is r*X*pi/360.
|
| A = [pi*(X*pi/360)^2] * r^2
|
| Androcles seems to think the only two possibilities are either
| no spread at all, or omnidirectional spread.
I did not say that, you stupid LYING *****!
Then why do you keep attributing the statement to me that
parabolas are omnidirectional, when all I am saying is that
they spread?
I never said omnidirectional. Yet you keep claiming I did.
Who is lying?
| There are other
| possibilities, such as a beam which is 1 degree wide. Such
| a beam increases in area proportional to r^2, but it isn't
| omnidirectional.
Ah... "OTHER POSSIBILITIES". "NOT OMNIDIRECTIONAL".
How true.
Very good.
Proportional, Blind Poe? WHAT FUCKING PROPORTION?
1/r^2, 2/r^2, r/r^2, r^2/r^2, 1/1, other?
Proportional to 1/r^2 means a constant times 1/r^2. You
knew that, right?
What inverse square law?
That was the question I asked you, STOOPID *****.
You haven't seen my answer(s)? OK, I'll try again: A circular
beam of diameter X degrees is spread over an area of
pi*r^*(X/360)^2 = [pi*X^2/360^2] * r^2 at distance r. If
the total energy is E, the intensity at distance r is
[E*360^2/(pi*X^2)] / r^2
That is proportional to 1/r^2. The proportionality constant
is [E*360^2/(pi*X^2)].
That inverse square law.
- Randy
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 11:13:50 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165553800.998080.220320@f1g2000cwa.googlegroups.com...
|=20
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165526906.374730.7090@l12g2000cwl.googlegroups.com...
| > |
| > | Randy Poe wrote:
| > | > Sorcerer wrote:
| > | > > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | > > | Androcles is currently cluttering multiple threads with his
| > | > > | assertion that beams from parabolic antennas experience no
| > | > > | 1/r^2 free-space loss.
| > | > >
| > | > > Correct, I am.
| > | > > Parabolic antennae (note spelling) are not omnidirectional
| > | > > antennae.
| > | >
| > | > No they aren't. I agree. They have very small angular width.
| > | > Their energy is radiated into a circular patch of very small
| > | > angular extent. It is the same angle at every distance.
| > | >
| > | > Is a 1 degree arc the same length at 10 m and 100 m?
| > | >
| > | > > If they were headlights on cars would be useless.
| > | >
| > | > Are headlights at 10 m just as bright as headlights
| > | > at 1 km?
| > | >
| > | > > What inverse square law, fuckhead?
| > | >
| > | > The one that says that a circular patch which is X degrees wide
| > | > has an area of pi*r^2*(X*pi/180)^2.
| > |
| > | Sorry, that's off by a factor of 4. Radius of a circular
| > | patch X degrees in diameter is r*X*pi/360.
| > |
| > | A =3D [pi*(X*pi/360)^2] * r^2
| > |
| > | Androcles seems to think the only two possibilities are either
| > | no spread at all, or omnidirectional spread.
| >
| >
| > I did not say that, you stupid LYING *****!
|=20
| Then why do you keep attributing the statement to me that
| parabolas are omnidirectional, when all I am saying is that
| they spread?
|=20
| I never said omnidirectional. Yet you keep claiming I did.
| Who is lying?
|=20
| > | There are other
| > | possibilities, such as a beam which is 1 degree wide. Such
| > | a beam increases in area proportional to r^2, but it isn't
| > | omnidirectional.
| >
| > Ah... "OTHER POSSIBILITIES". "NOT OMNIDIRECTIONAL".
| > How true.
|=20
| Very good.
|=20
| > Proportional, Blind Poe? WHAT FUCKING PROPORTION?
| > 1/r^2, 2/r^2, r/r^2, r^2/r^2, 1/1, other?
|=20
| Proportional to 1/r^2 means a constant times 1/r^2. You
| knew that, right?
|=20
| > What inverse square law?
| > That was the question I asked you, STOOPID *****.
|=20
| You haven't seen my answer(s)? OK, I'll try again: A circular
| beam of diameter X degrees is spread over an area of
| pi*r^*(X/360)^2 =3D [pi*X^2/360^2] * r^2 at distance r. If
| the total energy is E, the intensity at distance r is
| [E*360^2/(pi*X^2)] / r^2
|=20
| That is proportional to 1/r^2. The proportionality constant
| is [E*360^2/(pi*X^2)].
|=20
| That inverse square law.
According to the ***** Poe any parabolic antenna is=20
omnidirectional to make his math work, and cylindrical beams
are spherical. =20
Thank you for explaining that and mixing 360 degrees with
2pi radians.=20
I'll get rid of my car's headlight reflectors, you STOOOPID *****!!
.
|
|
|
|
|
|
| User: "Sue..." |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 03:36:06 PM |
|
|
Randy Poe wrote:
Randy Poe wrote:
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| Androcles is currently cluttering multiple threads with his
| assertion that beams from parabolic antennas experience no
| 1/r^2 free-space loss.
Correct, I am.
Parabolic antennae (note spelling) are not omnidirectional
antennae.
No they aren't. I agree. They have very small angular width.
Their energy is radiated into a circular patch of very small
angular extent. It is the same angle at every distance.
Is a 1 degree arc the same length at 10 m and 100 m?
If they were headlights on cars would be useless.
Are headlights at 10 m just as bright as headlights
at 1 km?
What inverse square law, fuckhead?
The one that says that a circular patch which is X degrees wide
has an area of pi*r^2*(X*pi/180)^2.
Sorry, that's off by a factor of 4. Radius of a circular
patch X degrees in diameter is r*X*pi/360.
A = [pi*(X*pi/360)^2] * r^2
Androcles seems to think the only two possibilities are either
no spread at all, or omnidirectional spread. There are other
possibilities, such as a beam which is 1 degree wide. Such
a beam increases in area proportional to r^2, but it isn't
omnidirectional.
- Randy
Androcles might take us to dinner with the King of Sweden
so don't pick on him.
<<Now, does not the prize to Einstein imply
that the Academy recognised the particle
nature of light? The Nobel Committee says
that Einstein had found that the energy exchange
between matter and ether occurs by atoms emitting
or absorbing a quantum of energy,hv .
As a consequence of the new concept of light quanta
(in modern terminology photons) Einstein proposed the
law that an electron emitted from a substance by
monochromatic light with the frequency has to have
a maximum energy of E=hv-p, where p is the energy needed to
remove the electron from the substance. Robert Andrews
Millikan carried out a series of measurements over a
period of 10 years, finally confirming the validity of this
law in 1916 with great accuracy. Millikan had, however,
found the idea of light quanta to be unfamiliar and strange.
The Nobel Committee avoids committing itself to the
particle concept. Light-quanta or with modern terminology,
photons, were explicitly mentioned in the reports on
which the prize decision rested only in connection with
emission and absorption processes. The Committee says
that the most important application of Einstein's photoelectric
law and also its most convincing confirmation has come from
the use Bohr made of it in his theory of atoms, which explains
a vast amount of spectroscopic data. >>
http://nobelprize.org/physics/articles/ekspong/index.html
Sue...
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 06:17:23 PM |
|
|
"Sue..." <suzysewnshow@yahoo.com.au> wrote in message =
news:1165527365.981031.114800@f1g2000cwa.googlegroups.com...
|=20
| Randy Poe wrote:
| > Randy Poe wrote:
| > > Sorcerer wrote:
| > > > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > > > | Androcles is currently cluttering multiple threads with his
| > > > | assertion that beams from parabolic antennas experience no
| > > > | 1/r^2 free-space loss.
| > > >
| > > > Correct, I am.
| > > > Parabolic antennae (note spelling) are not omnidirectional
| > > > antennae.
| > >
| > > No they aren't. I agree. They have very small angular width.
| > > Their energy is radiated into a circular patch of very small
| > > angular extent. It is the same angle at every distance.
| > >
| > > Is a 1 degree arc the same length at 10 m and 100 m?
| > >
| > > > If they were headlights on cars would be useless.
| > >
| > > Are headlights at 10 m just as bright as headlights
| > > at 1 km?
| > >
| > > > What inverse square law, fuckhead?
| > >
| > > The one that says that a circular patch which is X degrees wide
| > > has an area of pi*r^2*(X*pi/180)^2.
| >
| > Sorry, that's off by a factor of 4. Radius of a circular
| > patch X degrees in diameter is r*X*pi/360.
| >
| > A =3D [pi*(X*pi/360)^2] * r^2
| >
| > Androcles seems to think the only two possibilities are either
| > no spread at all, or omnidirectional spread. There are other
| > possibilities, such as a beam which is 1 degree wide. Such
| > a beam increases in area proportional to r^2, but it isn't
| > omnidirectional.
| > - Randy
|=20
| Androcles might take us to dinner with the King of Sweden
| so don't pick on him.
Be seen with you? I doubt the King of Sweden would enjoy=20
Burger King or McDonalds. "There are other possibilities",=20
such as "Wendy's" and "Denny's".
The King of Sweden might enjoy Honey Barbecued Spare
Ribs from Jade Garden in Chatham, England, Ginger
Prawns from Whiskey Pete's in Daytona Beach, Florida,
a Delmonico steak from Ambridge, Pennsylvania, or even
a seafood pizza from Calais, France, but such succulence=20
would be wasted on you, even if I know the best in the world.
I could make you scrambled eggs, I suppose. Bring your own=20
Maryland to Florida Callinectes sapidus. =20
http://www.jaxshells.org/bcrabs.jpg
Now shut up about food unless you have an airline ticket.=20
.
|
|
|
|
|
|
|
| User: "Sue..." |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 03:28:50 PM |
|
|
Sorcerer wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| Androcles is currently cluttering multiple threads with his
| assertion that beams from parabolic antennas experience no
| 1/r^2 free-space loss.
Correct, I am.
Parabolic antennae (note spelling) are not omnidirectional
antennae. If they were headlights on cars would be useless.
What inverse square law, fuckhead?
Androcles
Is isotropy spelled A-T-T-E-N-U-A-T-IO-N?
Is attenuation spelled I-S-O-T-R-O-P-Y?
Surely someone misspelled something here:
http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html
Sue...
.
|
|
|
| User: "Sorcerer" |
|
| Title: Re: Parabolas for Blind Poe. |
07 Dec 2006 06:27:24 PM |
|
|
"Sue..." <suzysewnshow@yahoo.com.au> wrote in message =
news:1165526930.265673.94720@80g2000cwy.googlegroups.com...
|=20
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message =
news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae. If they were headlights on cars would be useless.
| > What inverse square law, fuckhead?
| > Androcles
|=20
| Is isotropy spelled A-T-T-E-N-U-A-T-IO-N?
No.
| Is attenuation spelled I-S-O-T-R-O-P-Y?
No.
What inverse square law, fuckhead?
.
|
|
|
| User: "The Thing" |
|
| Title: Re: Parabolas for Blind Poe. |
08 Dec 2006 12:35:57 AM |
|
|
On Fri, 08 Dec 2006 00:27:24 +0000, Sorcerer wrote:
"Sue..." <suzysewnshow@yahoo.com.au> wrote in message news:1165526930.265673.94720@80g2000cwy.googlegroups.com...
|
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae. If they were headlights on cars would be useless.
| > What inverse square law, fuckhead?
| > Androcles
|
| Is isotropy spelled A-T-T-E-N-U-A-T-IO-N?
No.
| Is attenuation spelled I-S-O-T-R-O-P-Y?
No.
What inverse square law, fuckhead?
Proof by Tourette Syndrome. How could he possibly be wrong.
Regards
The
.
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| User: "Sue..." |
|
| Title: Antennas 101 for Androcles |
08 Dec 2006 01:15:22 AM |
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The Thing wrote:
On Fri, 08 Dec 2006 00:27:24 +0000, Sorcerer wrote:
"Sue..." <suzysewnshow@yahoo.com.au> wrote in message news:1165526930.265673.94720@80g2000cwy.googlegroups.com...
|
| Sorcerer wrote:
| > "Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
| > | Androcles is currently cluttering multiple threads with his
| > | assertion that beams from parabolic antennas experience no
| > | 1/r^2 free-space loss.
| >
| > Correct, I am.
| > Parabolic antennae (note spelling) are not omnidirectional
| > antennae. If they were headlights on cars would be useless.
| > What inverse square law, fuckhead?
| > Androcles
|
| Is isotropy spelled A-T-T-E-N-U-A-T-IO-N?
No.
| Is attenuation spelled I-S-O-T-R-O-P-Y?
No.
What inverse square law, fuckhead?
Proof by Tourette Syndrome. How could he possibly be wrong.
He isn't wrong. He just want to rewrite
all of physics and metrology. ;-)
Just is case anyone takes him seriously;
they can probably find the Androcles version of
these conforming to the Androcles physics,
on his website in a few weeks:
http://mathworld.wolfram.com/PolarCoordinates.html
http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html
http://www.ee.surrey.ac.uk/Personal/D.Jefferies/antennas.html
http://www.rp-photonics.com/gaussian_beams.html
http://nobelprize.org/physics/articles/ekspong/index.html
Save 'em on CD because they will likely disappear after
Androcles enlightens the world with his new math and
physics.
Sue...
Regards
The
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| User: "Dirk Van de moortel" |
|
| Title: Re: Antennas 101 for Androcles |
08 Dec 2006 05:33:01 PM |
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|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
Androcles is currently cluttering multiple threads with his
Randy, it seems you got him in panic mode again, while
he of course is trying to make it look like it's the other
way around.
Good job. Congratulations :-)
Dirk Vdm
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| User: "Dirk Van de moortel" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 01:34:45 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss. Rather than continue to clutter those
threads, let me put the relevant information into one place.
Engineers characterize every antenna by its gain, which
relates the power to omnidirectional power. A perfectly
omnidirectional antenna has a gain of 1, or 0 dB. Gain is
related to directivity. An antenna with a gain of 30 dB
(a factor of 1000) is highly directional. If receiving, it
gets its energy from about 1/1000-th of the sphere. If
transmitting, it is putting its energy out in 1/1000 of the
sphere and therefore the intensity is 1000 times higher
in that direction than if it tried to spread the energy in
all directions equally.
Good parabolic antennas have gains in the neighborhood
of 50 dB. Aside from shape, the most important parameter
affecting gain is D/lambda, the ratio of diameter to
wavelength. If the antenna is not circular, it is some other
characteristic length/lambda. If you take a given antenna
shape and double its size, but then double the wavelength,
you'll get the same gain.
The area of a sphere grows as r^2 where r is the radius
of the sphere. An antenna like Cassini's with a gain of
50 dB is transmitting its energy into 1/100000 of the
sphere. 1/100000 of a thing growing as r^2 is still growing
as r^2.
Now if you do simple ray tracing, it looks like every ray
leaving the focus and bouncing off a parabolic mirror should
exit parallel. So why is there a beamwidth?
First of all, it is because light is a wave, and the reflection
and focusing of waves is not so simple as ray-tracing. The
pattern from a parabolic antenna is very similar to the diffraction
pattern from a small circular hole, a pattern which also has
angular width ~ D/lambda.
Secondly, the focus is a point, and real antenna feeds
have a volume, so the energy is coming from places
that aren't exactly at the focus.
Third, the shape will never be exactly parabolic. In real
life, there are always variations.
- Randy
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Dirk Vdm
.
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|
|
| User: "Randy Poe" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 01:40:32 PM |
|
|
Dirk Van de moortel wrote:
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Since I actually work with EEs professionally, all of whom can
calculate antenna beamwidths in their sleep, I can state
confidently that whatever Androcles' background, it didn't include
what seems to be basic EE training.
- Randy
.
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|
|
| User: "Dirk Van de moortel" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 01:47:52 PM |
|
|
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165520432.228916.250040@n67g2000cwd.googlegroups.com...
Dirk Van de moortel wrote:
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Since I actually work with EEs professionally, all of whom can
calculate antenna beamwidths in their sleep, I can state
confidently that whatever Androcles' background, it didn't include
what seems to be basic EE training.
- Randy
hehe...
I wish you all the luck in the world. You'll need it ;-)
Dirk Vdm
.
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|
| User: "Sue..." |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 01:54:55 PM |
|
|
Randy Poe wrote:
Dirk Van de moortel wrote:
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Since I actually work with EEs professionally, all of whom can
calculate antenna beamwidths in their sleep, I can state
confidently that whatever Androcles' background, it didn't include
what seems to be basic EE training.
- Randy
Dork van der Pee Pee doesn't like anyone that
uses maths in the real world because he
knows they see right throught his symbol shuffling
shennanigans.
http://mathworld.wolfram.com/BellhopParadox.html
Sue...
.
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|
|
| User: "Phineas T Puddleduck" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 02:21:36 PM |
|
|
In article <1165521295.350436.269490@73g2000cwn.googlegroups.com>,
"Sue..." <suzysewnshow@yahoo.com.au> wrote:
Dork van der Pee Pee doesn't like anyone that
uses maths in the real world because he
knows they see right throught his symbol shuffling
shennanigans.
http://mathworld.wolfram.com/BellhopParadox.html
Still posting your nonsense Dennis?
--
Just \int_0^\infty du it!
--
Posted via a free Usenet account from http://www.teranews.com
.
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|
| User: "Gordon" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 01:59:30 PM |
|
|
On Thu, 07 Dec 2006 19:34:45 GMT, "Dirk Van de moortel"
<dirkvandemoortel@ThankS-NO-SperM.hotmail.com> wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message news:1165519259.245771.29120@16g2000cwy.googlegroups.com...
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss. Rather than continue to clutter those
threads, let me put the relevant information into one place.
Engineers characterize every antenna by its gain, which
relates the power to omnidirectional power. A perfectly
omnidirectional antenna has a gain of 1, or 0 dB. Gain is
related to directivity. An antenna with a gain of 30 dB
(a factor of 1000) is highly directional. If receiving, it
gets its energy from about 1/1000-th of the sphere. If
transmitting, it is putting its energy out in 1/1000 of the
sphere and therefore the intensity is 1000 times higher
in that direction than if it tried to spread the energy in
all directions equally.
Good parabolic antennas have gains in the neighborhood
of 50 dB. Aside from shape, the most important parameter
affecting gain is D/lambda, the ratio of diameter to
wavelength. If the antenna is not circular, it is some other
characteristic length/lambda. If you take a given antenna
shape and double its size, but then double the wavelength,
you'll get the same gain.
The area of a sphere grows as r^2 where r is the radius
of the sphere. An antenna like Cassini's with a gain of
50 dB is transmitting its energy into 1/100000 of the
sphere. 1/100000 of a thing growing as r^2 is still growing
as r^2.
Now if you do simple ray tracing, it looks like every ray
leaving the focus and bouncing off a parabolic mirror should
exit parallel. So why is there a beamwidth?
First of all, it is because light is a wave, and the reflection
and focusing of waves is not so simple as ray-tracing. The
pattern from a parabolic antenna is very similar to the diffraction
pattern from a small circular hole, a pattern which also has
angular width ~ D/lambda.
Secondly, the focus is a point, and real antenna feeds
have a volume, so the energy is coming from places
that aren't exactly at the focus.
Third, the shape will never be exactly parabolic. In real
life, there are always variations.
- Randy
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Dirk Vdm
Is Androcles a digital or an analog robot, or some combination of
the two? Or, did you mean "Electronics Engineer?" ;-)
.
|
|
|
| User: "Dirk Van de moortel" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 03:10:26 PM |
|
|
"Gordon" <gordonlr@DELETEswbell.net> wrote in message news:0fsgn2d5t6qu3mqjcdqtgj68lup564o15p@4ax.com...
On Thu, 07 Dec 2006 19:34:45 GMT, "Dirk Van de moortel"
<dirkvandemoortel@ThankS-NO-SperM.hotmail.com> wrote:
[snip]
This is all very nice, but you seem to forget one important
annoying but devastating little detail: Androcles is an
"Electronic Engineer, Professionaly".
Dirk Vdm
Is Androcles a digital or an analog robot, or some combination of
the two? Or, did you mean "Electronics Engineer?" ;-)
"Electronic Engineer, Professionaly".
Read all about it here:
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Engineer.html
Dirk Vdm
.
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| User: "Helmut Wabnig .... --. .- -... -. .. .-- @ .- --- -. DOT .- -" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 03:01:36 PM |
|
|
On 7 Dec 2006 11:20:59 -0800, "Randy Poe" <poespam-trap@yahoo.com>
wrote:
:...
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss. Rather than continue to clutter those
threads, let me put the relevant information into one place.
....
Nice.
Some number crunchers:
www.xlmicrowave.com/path_loss_&_fresnel_calculator.xls
www.ka9q.net/jjsat/full_links.xls
www.cqham.ru/projects/rf_calc.xls
www.stec2005.space.aau.dk/files/AMSAT-IARU_Link_Budget_Rev2.2.2.xls
http://www.viestikallio.fi/tools/eme-pathloss.php
www.amsat.org/amsat/ftp/software/spreadsheet/AMSAT-IARU_Link_Budget_Rev1.xls
http://www.satsig.net/linkbugt.htm
http://www.tutorialsweb.com/satcom/satellite-link-budget-calculator.htm
http://www.amsat.org/amsat-new/echo/Echo_Linkbudget.php
Some theory:
http://classweb.gmu.edu/jmontana/lecture04a.ppt
w.
.
|
|
|
| User: "Helmut Wabnig .... --. .- -... -. .. .-- @ .- --- -. DOT .- -" |
|
| Title: Re: Antennas 101 for Androcles |
07 Dec 2006 03:23:16 PM |
|
|
On Thu, 07 Dec 2006 22:01:36 +0100, Helmut Wabnig <.... --. .-
-... -. .. .-- @ .- --- -. DOT .- -> wrote:
On 7 Dec 2006 11:20:59 -0800, "Randy Poe" <poespam-trap@yahoo.com>
wrote:
:...
Androcles is currently cluttering multiple threads with his
assertion that beams from parabolic antennas experience no
1/r^2 free-space loss. Rather than continue to clutter those
threads, let me put the relevant information into one place.
....
Nice.
Some number crunchers:
www.xlmicrowave.com/path_loss_&_fresnel_calculator.xls
www.ka9q.net/jjsat/full_links.xls
www.cqham.ru/projects/rf_calc.xls
www.stec2005.space.aau.dk/files/AMSAT-IARU_Link_Budget_Rev2.2.2.xls
http://www.viestikallio.fi/tools/eme-pathloss.php
www.amsat.org/amsat/ftp/software/spreadsheet/AMSAT-IARU_Link_Budget_Rev1.xls
http://www.satsig.net/linkbugt.htm
http://www.tutorialsweb.com/satcom/satellite-link-budget-calculator.htm
http://www.amsat.org/amsat-new/echo/Echo_Linkbudget.php
Some theory:
http://classweb.gmu.edu/jmontana/lecture04a.ppt
w.
may I add
http://en.wikipedia.org/wiki/Friis_transmission_equation
.
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| User: "" |
|
| Title: Re: Antennas 101 for Androcles |
09 Dec 2006 04:17:48 AM |
|
|
On Dec 8, 12:20 am, "Randy Poe" <poespam-t...@yahoo.com> wrote:
First of all, it is because light is a wave, and the reflection
and focusing of waves is not so simple as ray-tracing. The
pattern from a parabolic antenna is very similar to the diffraction
pattern from a small circular hole, a pattern which also has
angular width ~ D/lambda.
- Randy
So light is a wave. EM wave! Technical terms, mathematics,
measurements come later. Will you or anybody else tell me what is EM
wave? In absence of aether, EM fields must actually travel. This is
possible in only two ways. One is like a bullet or the other is as
described by Maxwell's equations. Will you be able to give me rough
idea-a picture-about it? If time dependent EM fields are creating each
other around them, then forget 1/r^2, they will be ulmost completely
destroyed within few meters. This, inspite of the antenna design.
Secondly, what prevents generation of fields in all directions except
in the line of propagation, in a pulse of laser?
.
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