my SWR reading
 

Richard Fry wrote:
"Roy Lewallen" wrote:
All the power produced by the transmitter arrives at the antenna
less whatever is lost as heat in the transmission line.

How about a case of a non-resonant transmission line whose Zo equals the
load Z except for a discrete mismatch somewhere in the line?
Reflections from that mismatch will be dissipated in the reverse port
termination of a circulator installed at the input of the line. Clearly
not all of the power available at the output of the circulator arrived
at the antenna (less line loss).

Certainly if you install a resistor in the line, whether connected to a
circulator or not, some of the power leaving the transmitter won't make
it to the load. I was assuming when I made my statement that no such
objects were placed in the transmission line, and would hope this
condition would be obvious to most readers.

..Unless the line is perfectly matched, there will be repeating points
of high current and of high voltage. Depending on the nature of the
conductor and insulator, either or both of these can cause localized
heating. In the example you gave, the damage is almost certainly
caused by high current rather than high voltage. ...

I agree, and misunderstood your original post.

Roy Lewallen, W7EL

my SWR reading
 

Gene Fuller wrote:
That's a good one. I did not know that a transmission line is "free space".

It doesn't matter what the medium is - EM waves
obey the conservation of momentum principle in
any medium. Your "sloshing" waves violate that
accepted principle of physics. Sorry.
--
73, Cecil http://www.w5dxp.com

my SWR reading
 

Owen Duffy wrote:

SNIP


You didn't mention the balun, it is significant.

Owen

I can't comment on that as I did not make any measurements without a
balun. It was always going to have a balun because I did not want
any significant RF coming down the outside of the coax and causing
interference.

It would be a simple matter for Jim to make a balun like mine and I
imagine he'd get very similar results.



Charlie.

--
M0WYM
www.radiowymsey.org

my SWR reading
 

Cecil Moore wrote:
Gene Fuller wrote:
That's a good one. I did not know that a transmission line is "free
space".

It doesn't matter what the medium is - EM waves
obey the conservation of momentum principle in
any medium. Your "sloshing" waves violate that
accepted principle of physics. Sorry.

Cecil,

This entire thread is silly beyond belief. In any case, no matter how
irrelevant, there is no problem at all in balancing momentum when there
is lots of stuff around. Momentum is a completely useless concept in
this example.

But I will declare you to be the winner. 8-)

73,
Gene
W4SZ

my SWR reading
 

Gene Fuller wrote:
Momentum is a completely useless concept in this example.

Obviously useless for your side of the argument. :-)
--
73, Cecil http://www.w5dxp.com