On 10 May, 11:45, wrote:
robert casey wrote:
art wrote:
What is the ratio of magnetic electrons emitted from a radiator
compared with
with the number of electrons emmitted due to current flow?
What is the combination ratio required of both types of electrons to
form a radiation field?
Regards
Art

You mean the radiation from an antenna driven by a radio transmitter?
It doesn't emit electrons, but it does emit photons at that radio
frequency.
Go find a book on electromagnetism and fields, but be prepared for
calculus level math in that book. I took such a class 30 years ago, and
got a "C", and remember even less now. A high school physics book might
be enough depending on your needs.

The current (May/June) issue of QEX contains the article:

Electromagnetic Radiation: A Brief Tutorial

It contains equations but no calculus that I noticed.

"magnetic electrons emitted from a radiator" isn't mentioned, but
that isn't a surprise to most people.

--
Jim Pennino

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- Show quoted text -

Jim, you have no legitamacy in the subject of radiation, your past
posts prove that. On top of that you do not talk for most people as
you intimate.
You haven't yet capitulated on the static subject or negated the truth
of the mathematics and examples supplied. Just stating consistently
that you can't this or you can't that just doesn't elevate your
stature.

On 10 May, 12:06, art wrote:
On 10 May, 11:45, wrote:





robert casey wrote:
art wrote:
What is the ratio of magnetic electrons emitted from a radiator
compared with
with the number of electrons emmitted due to current flow?
What is the combination ratio required of both types of electrons to
form a radiation field?
Regards
Art

You mean the radiation from an antenna driven by a radio transmitter?
It doesn't emit electrons, but it does emit photons at that radio
frequency.
Go find a book on electromagnetism and fields, but be prepared for
calculus level math in that book. I took such a class 30 years ago, and
got a "C", and remember even less now. A high school physics book might
be enough depending on your needs.

The current (May/June) issue of QEX contains the article:

Electromagnetic Radiation: A Brief Tutorial

It contains equations but no calculus that I noticed.

"magnetic electrons emitted from a radiator" isn't mentioned, but
that isn't a surprise to most people.

--
Jim Pennino

Remove .spam.sux to reply.- Hide quoted text -

- Show quoted text -

Jim, you have no legitamacy in the subject of radiation, your past
posts prove that. On top of that you do not talk for most people as
you intimate.
You haven't yet capitulated on the static subject or negated the truth
of the mathematics and examples supplied. Just stating consistently
that you can't this or you can't that just doesn't elevate your
stature.- Hide quoted text -

- Show quoted text -

Some have stated that 377 ohms is a ratio. I don't understand that
assertion
since I understood that a ratio is not confined to a specific unit and
in fact
does not have units. I am aware that the impedance of a particular
atmosphere is 377 ohms but that is certainly not a ratio. Some say one
must have a knoweledge of calculus to understand radiation. Another
declares he read a book on radiation that did not use calculus which
is just as well if one becomes careless with terms such as a ratio.
But no matter, this newsgroup is a living example of the use of free
speech where amateurs can take on the guise of professionalism despite
their lowly education level.

art wrote:
I am aware that the impedance of a particular
atmosphere is 377 ohms but that is certainly not a ratio.

From: http://whatis.techtarget.com/definit...845268,00.html

Mathematically, the Zo of free space is equal to the square root of the
ratio of the permeability of free space (µo) in henrys per meter (H/m)
to the permittivity of free space (o) in farads per meter (F/m):

Zo = (µo/o)1/2

= [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2

= 377 ohms (approximately)

The exact value of the Zo of free space is 120 pi ohms, where pi is the
ratio of the circumference of a circle to its diameter.
--
73, Cecil, w5dxp.com

On 10 May, 12:58, Cecil Moore wrote:
art wrote:
I am aware that the impedance of a particular
atmosphere is 377 ohms but that is certainly not a ratio.

From:http://whatis.techtarget.com/definit...845268,00.html

Mathematically, the Zo of free space is equal to the square root of the
ratio of the permeability of free space (µo) in henrys per meter (H/m)
to the permittivity of free space (o) in farads per meter (F/m):

Zo = (µo/o)1/2

= [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2

= 377 ohms (approximately)

The exact value of the Zo of free space is 120 pi ohms, where pi is the
ratio of the circumference of a circle to its diameter.
--
73, Cecil, w5dxp.com

O.k. Cecil I will for the moment embrace that a ratio must have a unit
of measurement which puts me in line with all the amateurs of this
newsgroup (see I am flexible). I will also change from particles now,
to electrons and now to protons as requested ( see I am flexible
again)
For my interest, what is the unit that must be used for the front to
back ratio of a directive antenna?
Regards
Art

art wrote:
For my interest, what is the unit that must be used for the front to
back ratio of a directive antenna?

Power ratios are commonly stated in dB.
--
73, Cecil http://www.w5dxp.com

Art wrote:
"For my interest, what is the unit that must be used for front to back
ratio of a directive antenna?"

I must be an idiot for venturing an answer, but ratios can be just
numbers, but numbers have origins. If radiated power in one direction is
twice that in another (reference), we can say it has a directive gain of
two or we can say it has a 3 dB gain. Front to back ratios have the same
origins and units. For legitimacy, Terman says on page 871 of his 1955
opus:
"The directive gain can be expressed either as a power ratio, or in
terms of the equivalent number of decibels.

Best regards, Richard Harrison, KB5WZI

On 10 May, 14:41, (Richard Harrison) wrote:
Art wrote:

"For my interest, what is the unit that must be used for front to back
ratio of a directive antenna?"

I must be an idiot for venturing an answer, but ratios can be just
numbers, but numbers have origins. If radiated power in one direction is
twice that in another (reference), we can say it has a directive gain of
two or we can say it has a 3 dB gain. Front to back ratios have the same
origins and units. For legitimacy, Terman says on page 871 of his 1955
opus:
"The directive gain can be expressed either as a power ratio, or in
terms of the equivalent number of decibels.

Best regards, Richard Harrison, KB5WZI

So it is now the norm not to cancel units of measurement in physics?
Woe is me. Free speech takes on a new meaning for some but not
acceptable from others meaning a term for a formula can now be called
a ratio with units of one's choice. Still, this is amateur radio after
all, it does not have to follow professional standards as most was
learned in the CB era

art wrote:
So it is now the norm not to cancel units of measurement in physics?
Woe is me. Free speech takes on a new meaning for some but not
acceptable from others meaning a term for a formula can now be called
a ratio with units of one's choice. Still, this is amateur radio after
all, it does not have to follow professional standards as most was
learned in the CB era

Art, maybe you should take time to study "dimensional
analysis". It really opened my eyes a half-century ago.
If you want to divide joules by amps, just put the most
elementary dimensions into the division and see what
are the results.
--
73, Cecil http://www.w5dxp.com

art wrote:
On 10 May, 14:41, (Richard Harrison) wrote:
Art wrote:

"For my interest, what is the unit that must be used for front to back
ratio of a directive antenna?"

I must be an idiot for venturing an answer, but ratios can be just
numbers, but numbers have origins. If radiated power in one direction is
twice that in another (reference), we can say it has a directive gain of
two or we can say it has a 3 dB gain. Front to back ratios have the same
origins and units. For legitimacy, Terman says on page 871 of his 1955
opus:
"The directive gain can be expressed either as a power ratio, or in
terms of the equivalent number of decibels.

Best regards, Richard Harrison, KB5WZI

So it is now the norm not to cancel units of measurement in physics?
Woe is me. Free speech takes on a new meaning for some but not
acceptable from others meaning a term for a formula can now be called
a ratio with units of one's choice. Still, this is amateur radio after
all, it does not have to follow professional standards as most was
learned in the CB era

Example:

Forward gain = 12db
Reverse gain = 2db

Front to back ratio = 12db/2db = 6; no units as they cancel.

5th grade mathematics.

--
Jim Pennino

Remove .spam.sux to reply.

Richard Harrison wrote:
Art wrote:
"For my interest, what is the unit that must be used for front to back
ratio of a directive antenna?"

I must be an idiot for venturing an answer, but ratios can be just
numbers, but numbers have origins. If radiated power in one direction is
twice that in another (reference), we can say it has a directive gain of
two or we can say it has a 3 dB gain. . .

Forgive me for picking a nit here, but the front/back ratio is the ratio
of radiated *field strength* or radiated *power density*, not radiated
power. Strictly speaking, there is zero power radiated in any single
direction.

Roy Lewallen, W7EL