rickman wrote:
On 8/2/2015 4:20 AM, Jeff wrote:

No, there will be no energy "supplied from the feeder and conducted down
the coax outer" as it will all be conducted into the antenna and
radiated if the antenna is perfectly balanced. The power flowing up the
coax, when perfectly matched, will only 'see' the antenna load, not the
coax outer as and element in parallel.

Jeff

If it was perfectly balanced before you connected the feeder, it will no
longer be perfectly balanced once the shunt impedance to earth of the
coax braid is connected to *one* side of it. Dare I say that that is
why you need a balun? This asymmetrical shunt impedance is the source
of the whole question.


So if what you are saying is correct then terminating a piece of coax
with a 50 ohm resistor will not cause a perfect match and the load will
not be 50 ohms due to the shunt impedance to earth of the coax braid.

I think not.

Maybe you can draw a diagram and show yourself where the current flows.
The earth connection on the shield outside is in parallel with the
earth connection on the shield inside. You can't have any current flow
on the outside because any current flowing on the shield inside balances
with the current flowing in the center conductor. The resistor requires
the two currents are equal with none left to travel down the shield
outside.

Although I am still waiting for jim to explain his idea that there is no
current flow in the coax. If that is true it will make this a *very*
simple picture.

https://en.wikipedia.org/wiki/Transm....27s_equations

Read and understand the equations and it becomes obvious.



--
Jim Pennino