"Dave" wrote in message
...

"Reg Edwards" wrote in message
...

Reflected power is a mere fiction. Power which is not radiated from an
antenna never actually arrives there. In fact it never leaves the
transmitter.

but, but, but, i can SEE reflected power! it shows on my TDR, i can see
ghosts in video from it, i can measure it, i can catch it in a circulator!
how can it be fiction?!?!?!


Clearly there is reflected power. Just don't take the SWR meter too
literally. It does not actually measure power, but the scale has been fudged
so it indicates the correct power if the load is equal to some design value.
I can see a long thread here.

Tam/WB2TT

"Tam/WB2TT" wrote in message
...
Clearly there is reflected power. Just don't take the SWR meter too
literally. It does not actually measure power, but the scale has been
fudged
so it indicates the correct power if the load is equal to some design
value.
I can see a long thread here.

see my last replies to this thread... i'm done... cecil and reg are back and
will undoubtedly re-hash optical methods and conjugate matches till the
server dies... as for me, this thread is now over.

Reg:

Consider a signal generator connected through a circulator to the input of a
slotted line. The circulator provides a constant impedance to the signal
generator no matter what impedance is connected to the output port of the
circulator. Now, if your quote below is true, please explain the standing
wave pattern measured via the slotted line probe whenever the slotted line
itself is terminated in other than its characteristic impedance.

Also ponder this scenario. A transmitter is adjusted to deliver the maximum
output power of which it is capable (limited by its power supply) into a 50
ohm transmission line several wavelengths long, terminated in a 50 ohm
antenna. The transmission line is just barely rated to handle the power
delivered by the transmitter under these conditions.

Now something fails within the antenna, and its input Z rises to 2000 ohms.
If the transmitter has no protective circuits to shut it down, it will
continue to generate power, and the transmission line will arc/burn. Of
course, so might the tx output circuits, but let's say they are "very
robust," and the tx continues to operate.

What is the source of the additional power causing the line failure? The tx
already was delivering all the power it could before the failure, so it
isn't coming from there.

RF

Visit http://rfry.org for FM broadcast RF system papers.

____________________

"Reg Edwards" wrote
Reflected power is a mere fiction. Power which is not radiated
from an antenna never actually arrives there. In fact it never
leaves the transmitter.

If this old mind recalls correctly a TV station with an undesireable SWR
will not transmit a clear image to its viewers because the delayed
re-reflection arrives at the TV set later and casues a ghost or smear.
Could you please explain the "Reflected power is a mere fiction." and the
smear or ghost?

tnx
Hank WD5JFR
"Reg Edwards" wrote in message
...

"Richard Clark" wrote:
What you describe as reflection and re-reflection occurs between the
mismatched antenna and the tuner that has been adjusted to minimize
power returned to the transmitter. The sole function of the tuner is
to keep this power from being dissipated by the transmitter (common
experience of arcing, denoting a voltage reflection, or thermal
runaway, denoting a current reflection). The "virtual" reflection
(offered by the tuner) is generally know as the complex conjugate of
the remote load, seen at the near end of the line through which it is
returning. This means that the line transforms the phase and
amplitude of the reflection, and the tuner's job is to invert that
relationship to counteract it, and return it to the antenna.

There are both wave descriptions of this process, and lumped circuit
equivalents. Both work, and both describe the same process from
different points of view. One does not negate the other's validity
(unless, of course, you attempt to mix the points of view and demand
consistency in terms - a frequent rhetorical trap here).

There will no doubt be a flurry of denials to this simple example with
contortions of logic to match. As for the math, you will find it by
the reams, once you've been overwhelmed with the arcana of hyperbolic
descriptions of a novel physics that have to proceed its proof.

Keep your eye on how your literal points in your question go abandoned
with these arcane theories.

73's
Richard Clark, KB7QHC
====================================

Dear Richard, you are confusing the matter even further, if that were
possible.

The only saving grace about your tedius message is that you yourself
eventually realise what a load of overcomplicated nonsense it is.

Reflected power is a mere fiction. Power which is not radiated from an
antenna never actually arrives there. In fact it never leaves the
transmitter.

All the power which leaves the transmiter is radiated except for that
which
is lost in the line. It has nowhere else to go!

But for the existence of so-called SWR meters, the words 'forward and
reflected power' would never enter people's vocabularies. For the few who
become involved with such matters, the misleading fiction also appears in
the language of mathematics.

Names have to be invented in order to discuss mathematical equations in
plain English. But there's no reason why they should be propagated, just
to
confuse, into the real World.

The sole purpose of an SWR meter is to indicate whether or not the
transmitter is loaded with 50 ohms.
----
Reg, G4FGQ

Hank:

Aren't you confusing the reflections that a TV signal experiences when
it bounces off nearby buildings and structures (causing ghosts) with
transmission line refections -- two entirely different things.

Al


"Henry Kolesnik" wrote in message om...
If this old mind recalls correctly a TV station with an undesireable SWR
will not transmit a clear image to its viewers because the delayed
re-reflection arrives at the TV set later and casues a ghost or smear.
Could you please explain the "Reflected power is a mere fiction." and the
smear or ghost?

tnx
Hank WD5JFR
"Reg Edwards" wrote in message
...

"Richard Clark" wrote:
What you describe as reflection and re-reflection occurs between the
mismatched antenna and the tuner that has been adjusted to minimize
power returned to the transmitter. The sole function of the tuner is
to keep this power from being dissipated by the transmitter (common
experience of arcing, denoting a voltage reflection, or thermal
runaway, denoting a current reflection). The "virtual" reflection
(offered by the tuner) is generally know as the complex conjugate of
the remote load, seen at the near end of the line through which it is
returning. This means that the line transforms the phase and
amplitude of the reflection, and the tuner's job is to invert that
relationship to counteract it, and return it to the antenna.

There are both wave descriptions of this process, and lumped circuit
equivalents. Both work, and both describe the same process from
different points of view. One does not negate the other's validity
(unless, of course, you attempt to mix the points of view and demand
consistency in terms - a frequent rhetorical trap here).

There will no doubt be a flurry of denials to this simple example with
contortions of logic to match. As for the math, you will find it by
the reams, once you've been overwhelmed with the arcana of hyperbolic
descriptions of a novel physics that have to proceed its proof.

Keep your eye on how your literal points in your question go abandoned
with these arcane theories.

73's
Richard Clark, KB7QHC
====================================

Dear Richard, you are confusing the matter even further, if that were
possible.

The only saving grace about your tedius message is that you yourself
eventually realise what a load of overcomplicated nonsense it is.

Reflected power is a mere fiction. Power which is not radiated from an
antenna never actually arrives there. In fact it never leaves the
transmitter.

All the power which leaves the transmiter is radiated except for that
which
is lost in the line. It has nowhere else to go!

But for the existence of so-called SWR meters, the words 'forward and
reflected power' would never enter people's vocabularies. For the few who
become involved with such matters, the misleading fiction also appears in
the language of mathematics.

Names have to be invented in order to discuss mathematical equations in
plain English. But there's no reason why they should be propagated, just
to
confuse, into the real World.

The sole purpose of an SWR meter is to indicate whether or not the
transmitter is loaded with 50 ohms.
----
Reg, G4FGQ

On 23 May 2004 19:02:20 -0700, (alhearn) wrote:

Hank:

Aren't you confusing the reflections that a TV signal experiences when
it bounces off nearby buildings and structures (causing ghosts) with
transmission line refections -- two entirely different things.

Al

Hi Al,

No, he has it correct. There is no material difference between the
two except for the velocity constant (which has no bearing on the
matter).

73's
Richard Clark, KB7QHC

SWR ghosts are usually smear because the transmission line is short and the
displacement fo the image is small compared to object reflection shost which
have a greater image displacement becasue the reflected signal travels over
a greater distance.
73
Hank WD5JFR
"alhearn" wrote in message
om...
Hank:

Aren't you confusing the reflections that a TV signal experiences when
it bounces off nearby buildings and structures (causing ghosts) with
transmission line refections -- two entirely different things.

Al


"Henry Kolesnik" wrote in message
om...
If this old mind recalls correctly a TV station with an undesireable SWR
will not transmit a clear image to its viewers because the delayed
re-reflection arrives at the TV set later and casues a ghost or smear.
Could you please explain the "Reflected power is a mere fiction." and
the
smear or ghost?

tnx
Hank WD5JFR
"Reg Edwards" wrote in message
...

"Richard Clark" wrote:
What you describe as reflection and re-reflection occurs between the
mismatched antenna and the tuner that has been adjusted to minimize
power returned to the transmitter. The sole function of the tuner
is
to keep this power from being dissipated by the transmitter (common
experience of arcing, denoting a voltage reflection, or thermal
runaway, denoting a current reflection). The "virtual" reflection
(offered by the tuner) is generally know as the complex conjugate of
the remote load, seen at the near end of the line through which it
is
returning. This means that the line transforms the phase and
amplitude of the reflection, and the tuner's job is to invert that
relationship to counteract it, and return it to the antenna.

There are both wave descriptions of this process, and lumped circuit
equivalents. Both work, and both describe the same process from
different points of view. One does not negate the other's validity
(unless, of course, you attempt to mix the points of view and demand
consistency in terms - a frequent rhetorical trap here).

There will no doubt be a flurry of denials to this simple example
with
contortions of logic to match. As for the math, you will find it by
the reams, once you've been overwhelmed with the arcana of
hyperbolic
descriptions of a novel physics that have to proceed its proof.

Keep your eye on how your literal points in your question go
abandoned
with these arcane theories.

73's
Richard Clark, KB7QHC
====================================

Dear Richard, you are confusing the matter even further, if that were
possible.

The only saving grace about your tedius message is that you yourself
eventually realise what a load of overcomplicated nonsense it is.

Reflected power is a mere fiction. Power which is not radiated from
an
antenna never actually arrives there. In fact it never leaves the
transmitter.

All the power which leaves the transmiter is radiated except for that
which
is lost in the line. It has nowhere else to go!

But for the existence of so-called SWR meters, the words 'forward and
reflected power' would never enter people's vocabularies. For the few
who
become involved with such matters, the misleading fiction also appears
in
the language of mathematics.

Names have to be invented in order to discuss mathematical equations
in
plain English. But there's no reason why they should be propagated,
just
to
confuse, into the real World.

The sole purpose of an SWR meter is to indicate whether or not the
transmitter is loaded with 50 ohms.
----
Reg, G4FGQ

Reg Edwards wrote:
Reflected power is a mere fiction. Power which is not radiated from an
antenna never actually arrives there. In fact it never leaves the
transmitter.

Therefore, radar cannot work since it relies upon reflected
joules/second. Mirrors also cannot work since there is an ExB
amount of power in those reflections.

Reg, for a 291.5 ohm antenna to accept 100 watts requires the forward
power to the antenna to be 200 watts. 100 watts is accepted by the
antenna and 100 watts is rejected by the antenna. 200 watts to the
antenna is routinely accomplished by a 100 watt ham transmitter and
a Z0-match provided by a tuner.

This is exactly like a partially silvered mirror that reflects half
the irradiance and allows half the irradiance through.

Assume a one second long lossless unterminated transmission line.
Pour 1000 watts into it for one second. During the next second, we
disconnect the line from the source and you grab the two wires, one
in each hand. Then tell us whether reflected power exists or not.
--
73, Cecil http://www.qsl.net/w5dxp



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Cecil Moore wrote:

Reg Edwards wrote:

Reflected power is a mere fiction. Power which is not radiated from an
antenna never actually arrives there. In fact it never leaves the
transmitter.


Therefore, radar cannot work since it relies upon reflected
joules/second. Mirrors also cannot work since there is an ExB
amount of power in those reflections.

I made note of this in a thread I just started. Is this a good analogy?
Certainly the signal goes out, hits something and then comes back.
Wouldn't this scramble the signal by some definable amount in an antenna?


Reg, for a 291.5 ohm antenna to accept 100 watts requires the forward
power to the antenna to be 200 watts. 100 watts is accepted by the
antenna and 100 watts is rejected by the antenna. 200 watts to the
antenna is routinely accomplished by a 100 watt ham transmitter and
a Z0-match provided by a tuner.

This is exactly like a partially silvered mirror that reflects half
the irradiance and allows half the irradiance through.

Assume a one second long lossless unterminated transmission line.
Pour 1000 watts into it for one second. During the next second, we
disconnect the line from the source and you grab the two wires, one
in each hand. Then tell us whether reflected power exists or not.

All we have to do is get an antenna that is 186,347.3233361 miles long.
Or would that be 122,989.233401 miles?

At any rate, the answer should be pretty easy to verify by using a very
long but practical sized antenna. Anyone done that?

- Mike KB3EIA -

Mike Coslo wrote:

Cecil Moore wrote:
Therefore, radar cannot work since it relies upon reflected
joules/second. Mirrors also cannot work since there is an ExB
amount of power in those reflections.

I made note of this in a thread I just started. Is this a good
analogy? Certainly the signal goes out, hits something and then comes
back. Wouldn't this scramble the signal by some definable amount in an
antenna?

Of course, but the point is that there exists energy as power, ExH,
in the reflected wave. If there is no energy in a reflected wave,
radar wouldn't work. Anyone who says there is no energy in a
reflected wave is just pulling your leg.

Assume a one second long lossless unterminated transmission line.
Pour 1000 watts into it for one second. During the next second, we
disconnect the line from the source and you grab the two wires, one
in each hand. Then tell us whether reflected power exists or not.

At any rate, the answer should be pretty easy to verify by using a
very long but practical sized antenna. Anyone done that?

Anyone who has ever used a TDR on a mismatched transmission line.
--
73, Cecil http://www.qsl.net/w5dxp



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