I've been reviewing my 1950s college textbooks to
see where my concepts came from. Here's a couple
of example quotes:

"Transmission Lines and Networks", Walter C. Johnson,
(c) 1950.

"... when the load reflects part of the incident energy,
it is found that the rms voltage and current vary almost
periodically along the line. This *effect* is *caused*
by the *interference* between the incident and reflected
waves, and the *resultant* variation is called a standing
wave."

The idea that interference *causes* effects (such as
standing waves) was not originated by me.

"Fields and Waves in Modern Radio", Ramo and Whinnery,
(c) 1944, 1953

"... energy cannot pass the perfect conductor ... Hence
all *energy brought* by the incident wave must be returned
in a reflected wave."

The idea that waves *bring* energy and that there is actual
energy in a reflected wave was not originated by me.

These concepts were probably around before I was born.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

The idea that interference *causes* effects (such as
standing waves) was not originated by me.

It must have taken great courage to admit that. Perhaps there's some
consolation in the fact that you can still take credit for originating
the idea that interference causes waves to reflect. :-)

The idea that waves *bring* energy and that there is actual
energy in a reflected wave was not originated by me.

Believe it or not, even prior to the advent of radio it was presumed
that waves transport energy, from the Sun to the Earth for example.
Still, it must be a humbling concession to make. :-)

ac6xg

Jim Kelley wrote:
Cecil Moore wrote:
The idea that interference *causes* effects (such as
standing waves) was not originated by me.

It must have taken great courage to admit that. Perhaps there's some
consolation in the fact that you can still take credit for originating
the idea that interference causes waves to reflect. :-)

I have *never* said I was uttering anything original. I
am on record for learning all this in college 50 years
ago. Any prudent physicist would be forced by reality to
admit that the principle of conservation principle is valid
and the wave reflection model is valid. If you accept the
validity of those two models, you cannot help but realize
that wave cancellation results in reflections.

If two coherent waves are canceled in one direction in a
transmission line, where do their energy components go?
It's a no-brainer. There is only one other direction
available.

The idea that waves *bring* energy and that there is actual
energy in a reflected wave was not originated by me.

Believe it or not, even prior to the advent of radio it was presumed
that waves transport energy, from the Sun to the Earth for example.
Still, it must be a humbling concession to make. :-)

I have never asserted that anything I have presented was
original. I have said I learned it all in college 50 years ago.

Some have asserted that reflected waves must not contain any
energy because they don't care where the energy goes. Such are
the delusions of grandeur exhibited by some on this newsgroup.
--
73, Cecil http://www.w5dxp.com

On Dec 11, 10:29 am, Cecil Moore wrote:
I've been reviewing my 1950s college textbooks to
see where my concepts came from. Here's a couple
of example quotes:

"Transmission Lines and Networks", Walter C. Johnson,
(c) 1950.

"... when the load reflects part of the incident energy,
it is found that the rms voltage and current vary almost
periodically along the line. This *effect* is *caused*
by the *interference* between the incident and reflected
waves, and the *resultant* variation is called a standing
wave."

The idea that interference *causes* effects (such as
standing waves) was not originated by me.

"Fields and Waves in Modern Radio", Ramo and Whinnery,
(c) 1944, 1953

"... energy cannot pass the perfect conductor ... Hence
all *energy brought* by the incident wave must be returned
in a reflected wave."

The idea that waves *bring* energy and that there is actual
energy in a reflected wave was not originated by me.

These concepts were probably around before I was born.
--
73, Cecil http://www.w5dxp.com

Did Johnson really say "almost periodically"?
Pretty close to periodic, but not quite? Hmmmm!

I suppose it just shows that even the best write
with a bit of laxness now and then.

Short quotations without the context are so unfair.

....Keith

Keith Dysart wrote:
On Dec 11, 10:29 am, Cecil Moore wrote:
I've been reviewing my 1950s college textbooks to
see where my concepts came from. Here's a couple
of example quotes:

"Transmission Lines and Networks", Walter C. Johnson,
(c) 1950.

"... when the load reflects part of the incident energy,
it is found that the rms voltage and current vary almost
periodically along the line. This *effect* is *caused*
by the *interference* between the incident and reflected
waves, and the *resultant* variation is called a standing
wave."

. . .
Did Johnson really say "almost periodically"?
Pretty close to periodic, but not quite? Hmmmm!

I suppose it just shows that even the best write
with a bit of laxness now and then.

Short quotations without the context are so unfair.

...Keith

Yes, Johnson said that, but it's due to being precise rather than lax.
Much of the following sections deals with lines having loss, so his
statement is quite apparently intended to include them.

Roy Lewallen, W7EL

Keith Dysart wrote:
Did Johnson really say "almost periodically"?
Pretty close to periodic, but not quite? Hmmmm!

Yep, Johnson was very accurate. The "almost" could
be dropped from the statement for a lossless condition.

I suppose it just shows that even the best write
with a bit of laxness now and then.

It's the opposite of laxness that caused him to use
the word "almost".
--
73, Cecil http://www.w5dxp.com

On Dec 11, 10:24 pm, Roy Lewallen wrote:
Keith Dysart wrote:
On Dec 11, 10:29 am, Cecil Moore wrote:
I've been reviewing my 1950s college textbooks to
see where my concepts came from. Here's a couple
of example quotes:

"Transmission Lines and Networks", Walter C. Johnson,
(c) 1950.

"... when the load reflects part of the incident energy,
it is found that the rms voltage and current vary almost
periodically along the line. This *effect* is *caused*
by the *interference* between the incident and reflected
waves, and the *resultant* variation is called a standing
wave."

. . .
Did Johnson really say "almost periodically"?
Pretty close to periodic, but not quite? Hmmmm!

I suppose it just shows that even the best write
with a bit of laxness now and then.

Short quotations without the context are so unfair.

...Keith

Yes, Johnson said that, but it's due to being precise rather than lax.
Much of the following sections deals with lines having loss, so his
statement is quite apparently intended to include them.

Ooooppppss. My apologies to Johnson.

I suppose I have just proved my own point that
taking sentences out of context can lead to
incorrect interpretations.

....Keith