This program models the behaviour of a transmission line plus antenna.
The line impedance can have any Zo. The antenna feedpoint impedance
can be any value of R+jX. Line length can be any fraction and number
of wavelengths. Line overall attenuation can be any value of dBs.

There is an SWR meter located at each end of the line. The meters also
indicate the reflection coefficients at the locations. Meter Zo can
be set equal to line Zo or to the standard 50 ohms.

Line input impedance can be observed to change versus line length in
wave-lengths, line attenuation and antenna impedance. The transforming
action of the line can be demonstrated. The smaller SWR and reflection
coefficient at the transmitter end of the line can be seen. The exact
increase in loss due to standing waves on the line is calculated.

The program can be used in practical applications and also for
educational purposes. It is hoped it may prevent the outbreaks in
violence which frequently occur in newsgroups about the meanings of
SWR and the notions of reflected power.

Download program SWRARGUE from website below in a few seconds. File
size = 41 Kbytes. Run immediately. No unzipping inconvenience.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

"Reg Edwards" wrote in message
...
This program models the behaviour of a transmission line plus antenna.
The line impedance can have any Zo. The antenna feedpoint impedance
can be any value of R+jX. Line length can be any fraction and number
of wavelengths. Line overall attenuation can be any value of dBs.

There is an SWR meter located at each end of the line. The meters also
indicate the reflection coefficients at the locations. Meter Zo can
be set equal to line Zo or to the standard 50 ohms.

Line input impedance can be observed to change versus line length in
wave-lengths, line attenuation and antenna impedance. The transforming
action of the line can be demonstrated. The smaller SWR and reflection
coefficient at the transmitter end of the line can be seen. The exact
increase in loss due to standing waves on the line is calculated.

The program can be used in practical applications and also for
educational purposes. It is hoped it may prevent the outbreaks in
violence which frequently occur in newsgroups about the meanings of
SWR and the notions of reflected power.

Download program SWRARGUE from website below in a few seconds. File
size = 41 Kbytes. Run immediately. No unzipping inconvenience.
----
.................................................. .........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. .........
Reg, the two SWR meters, one at each of the line, follows precisely the
method I presented in Appendix 8 of Reflections 2 to explain how to
determine the additional line attenuation attributed to SWR. Appendix 8 can
be found on my web site at w2du.com. Click on 'Read Appendices from
Reflections 2', then click on Appendix 8.

Walt, W2DU

Walt,

As suggested, I looked up your paper in your website about "Additional
power lost in trans-lines due to SWR."

It is applied only to coaxial lines, of course, because the usual SWR
meter cannot be used on balanced twin lines. Actually it applies to
all lines.

I think your calculating formula is an approximation. It is due to the
SWR meter discarding all information about the PHASE ANGLE of
reflections. ie., the angle of the reflection coefficient (Gamma) from
which you have used to calculate SWR in your explanation.

Gamma has an angle which can lie in any of the four quadrants.
Theoretically this cannot be neglected.

I can't prove the approximation because I havn't the mental energy to
do the exact calculations involved.

For interest, my program SWRARGUE calculates the exact power lost in
the line for any SWR for a given input power of 100 watts. Power lost
is then a percentage of input power. Transmission efficiency then
follows. Note that the internal resistance of the transmitter or
conjugate matching is immaterial.

It does this by first of all calculating the input impedance of the
line, when terminated with the antenna feedpoint impedance, in the
form of Rin + jXin.

From the input power it then calculates the line input current and
volts.

From normal transmission line formulae it then calculates line output
current and volts.

It then calculates the power dissipated in the antenna input resistive
component. This is the power radiated.

The difference between radiated power and 100 watts line input must be
the power lost in the line. Line efficiency and the decibels follow.

The excess loss due to SWR is the difference between actual loss and
the line's overall matched attenuation, which is an input to the
program. Which, to me, appears to be an artificial way of looking at
things and your approximation arises from it.

The way to prove the point is to calculate the excess loss due to SWR
your way and compare with the results from my program.

I wouldn't be surprised if there's no significant difference. The
matter about the imaginary meanings of SWR and confusing reflected
power is not worth the trouble of arguing about.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

Reg, our thoughts and prayers go out to your countrymen after the cowardly
attacks on your transportition system

"Reg Edwards" wrote in message
...
Walt,

As suggested, I looked up your paper in your website about "Additional
power lost in trans-lines due to SWR."

"Reg Edwards" wrote in message
...
Walt,

As suggested, I looked up your paper in your website about "Additional
power lost in trans-lines due to SWR."

It is applied only to coaxial lines, of course, because the usual SWR
meter cannot be used on balanced twin lines. Actually it applies to
all lines.

Reg, my Appendix does not apply only to coaxial lines. Like you also said,
it applies to all lines. Balanced twin lines also have SWR, as you already
know, but my words didn't limit measurements of SWR only to coaxial lines.
There are ways of measuring the SWR on open-wire lines other than
instruments limited to use on coaxial lines.

I think your calculating formula is an approximation. It is due to the
SWR meter discarding all information about the PHASE ANGLE of
reflections. ie., the angle of the reflection coefficient (Gamma) from
which you have used to calculate SWR in your explanation.

No approximations at all, Reg. As you know, reflection is the cause of SWR,
not the reverse. Further, the coefficient of the reflection that results in
SWR is the magnitude of the complex value in polar form. Therefore the
magnitude of the SWR is determined by the complex reflection coefficient,
resulting in the correct value, not an approximation. The complex reflection
coefficient can be used to determine the complex impedance. SWR simply lacks
the angle of the polar information, and is thus unable to supply the
required information to determine complex impedance. Thus the value of SWR
does provide the polar magnitude of the complex reflection coefficient, not
just the |rho| value.

Gamma has an angle which can lie in any of the four quadrants.
Theoretically this cannot be neglected.

And I submit, Reg, that although the numerical value of the angle is
omitted, the effect of the angle has not been neglected.

I can't prove the approximation because I havn't the mental energy to
do the exact calculations involved.

I'm saving you the mental energy, Reg, because there are no approximations
involved--the exact calculation has been made.

For interest, my program SWRARGUE calculates the exact power lost in
the line for any SWR for a given input power of 100 watts. Power lost
is then a percentage of input power. Transmission efficiency then
follows. Note that the internal resistance of the transmitter or
conjugate matching is immaterial.

I downloaded your SWRARGUE program, Reg, and ran it. The numbers using your
program and those using my Appendix 8 are identical.

snip

The excess loss due to SWR is the difference between actual loss and
the line's overall matched attenuation, which is an input to the
program. Which, to me, appears to be an artificial way of looking at
things and your approximation arises from it.

As I said above, Reg, the values obtained using your program and those using
my Appendix 8 are identical. My method does not reveal any approximate
values, so it cannot be an artificial way of viewing the procedure.

The way to prove the point is to calculate the excess loss due to SWR
your way and compare with the results from my program.

As I just said, I have compared my results with those of your program and
the resulting numbers are identical.

I wouldn't be surprised if there's no significant difference. The
matter about the imaginary meanings of SWR and confusing reflected
power is not worth the trouble of arguing about.

Not only is there no significant difference, Reg, there is NO difference.
Think about it.

Walt, W2DU

"Fred W4JLE" wrote -
Reg, our thoughts and prayers go out to your countrymen after the
cowardly
attacks on your transportition system.

---------------------------------------------------------

Fred, your sincere sentiments are very much appreciated. But we also
have in mind the 100's of thousands of Iraqis who have died under
attack during the last dozen years.
----
Yours, Reg.

Reg Edwards wrote:
"Fred W4JLE" wrote -

Reg, our thoughts and prayers go out to your countrymen after the

cowardly

attacks on your transportition system.


---------------------------------------------------------

Fred, your sincere sentiments are very much appreciated. But we also
have in mind the 100's of thousands of Iraqis who have died under
attack during the last dozen years.
----
Yours, Reg.


I see you ignored the fact that the internal strife and dictatorship
murdered far more per day than any out side influence may have caused.

Walt, my suspicion about approximation, based only on appearance, was
not justified.

So your "two SWR meter" formula and my program agree exactly.
Therefore your formula must be correct. ;o)

Thanks for your trouble to sort things out for me.
----
Reg, G4FGQ

Reg Edwards wrote:

"Fred W4JLE" wrote -

Reg, our thoughts and prayers go out to your countrymen after the

cowardly

attacks on your transportition system.


---------------------------------------------------------

Fred, your sincere sentiments are very much appreciated. But we also
have in mind the 100's of thousands of Iraqis who have died under
attack during the last dozen years.
----
Yours, Reg.


Where are these Hundreds of Thousands coming from? The defeat of the
Iraqi Army during Desert Storm. That was a conflict started by the Iraqi
President. The US President lead the army that defeated him. The
majority of the casualties suffered during the current action have been
the result a deliberate campaign by those opposed to the Iraqi people
guiding their own destiny. To say otherwise is to devalue the lives lost
in this action. I look foreword to the day that all non Iraqi military
personnel can go home in peace and with honor.

Dave N

Reg Edwards wrote:
"Fred W4JLE" wrote -

Reg, our thoughts and prayers go out to your countrymen after the

cowardly

attacks on your transportition system.


---------------------------------------------------------

Fred, your sincere sentiments are very much appreciated. But we also
have in mind the 100's of thousands of Iraqis who have died under
attack during the last dozen years.
----
Yours, Reg.



Not to mention the millions killed in interesting and novel ways by the
Hesein family and their puppets.

tom
K0TAR