"Dr. Slick" wrote in message
om...
"Tarmo Tammaru" wrote in message
...
"Dr. Slick" wrote in message
om...

But they never explain WHY a lossy line can INCREASE the
reflected power! The lossless line would not attenuate the reflected
wave at all!

I don't trust their claims on this.

If you get more power reflected than you send into a passive
network, you are getting energy from nowhere, and are thus violating
conservation of energy.


But the reflection coefficient is for Voltage. I think the clew lies in "The
main point of interest lies in the fact that we cannot, in general,
superpose the average powers carried by incident and reflected waves on a
dissipative line, although we could do so on a lossless line" A/C/F
.

I don't see the problem. 100 /_30 degrees divided by 2/_5 degrees is
50/_15
degrees. Different phase angle. By general case they mean not the
lossless
case.


I believe you mean 50 @ 25 degrees.


Yeah, I started typing this line before I had decided what numbers to use.



Also, they go from equation 5.12 to 5.13 without showing us how
they got there.

They use the identity e**jx = cos x + jsin x



Yes? And? How did they get the Zo=(Zn-1)/(Zn+1) from this?


I think the math is the same as for a lossless line

As I said out front. The book is copyrighted 1960. There is a certain
life
to these things.

Tam


But it seems to be out of print, perhaps with good reason...


Slick
The "print file" for a book used to be stored on hundreds of tin or lead
plates. Two N pages per plate. After printing some number of books, these
plates would have been recycled. I don't know that there was not a newer
edition.

Tam/WB2TT

"Tarmo Tammaru" wrote in message ...

But they never explain WHY a lossy line can INCREASE the
reflected power! The lossless line would not attenuate the reflected
wave at all!

I don't trust their claims on this.

If you get more power reflected than you send into a passive
network, you are getting energy from nowhere, and are thus violating
conservation of energy.


But the reflection coefficient is for Voltage. I think the clew lies in "The
main point of interest lies in the fact that we cannot, in general,
superpose the average powers carried by incident and reflected waves on a
dissipative line, although we could do so on a lossless line" A/C/F


But the square of the MAGNITUDE of the Voltage RC is the power
RC.

They never tell us why, and i don't think a lossy line will
increase your chances of getting rho1. In fact, i don't believe this
is possible with a passive network.





Also, they go from equation 5.12 to 5.13 without showing us how
they got there.

They use the identity e**jx = cos x + jsin x



Yes? And? How did they get the Zo=(Zn-1)/(Zn+1) from this?


I think the math is the same as for a lossless line



What is not understood is how one gets from:

Voltage R. C.= (Vr/Vi)e**(2*y*z)

where y=sqrt((R+j*omega*L)(G+j*omega*C))
and z= distance from load

To:

Voltage RC=(Z1-Z0)/(Z1+Z0) for purely real Zo
or Voltage RC=(Z1-Z0*)/(Z1+Z0)

And i have NO problems with the normalized formula,
AS LONG AS Zo IS PURELY REAL.

If Zo is complex, then Zo*/Zo is certainly NOT equal to
one!

I don't really trust this book too much, maybe that's why
it is out of print.



The "print file" for a book used to be stored on hundreds of tin or lead
plates. Two N pages per plate. After printing some number of books, these
plates would have been recycled. I don't know that there was not a newer
edition.

Tam/WB2TT



A book can always be reprinted if there is a demand.
Possibly no one bought the book because it's incorrect?


Slick