I am not sure what you mean by -always-. If you mean there is no such thing as a
perfect coax line then your statement is true but does not add any real value.
If you mean by -always- the feedline is a significant component in the antenna
system then I would have to disagree. When operated at their design point coax
transmission lines do not radiate and are not part of the radiating "antenna
system".

Coax is designed to work in a specific environment as a transmission line. These
transmission lines are designed not to radiate. When transmission lines are
operated significantly outside their design range the radiate. Adding a tuner to
one end only controls the characteristics at that point. It does not 'clean up'
the mismatchs.

Dan



Wes Stewart wrote:
On Sat, 27 Aug 2005 14:31:06 -0700, dansawyeror
wrote:


Since you are talking about 50 Ohms I assume you are talking about a
transmission line. If that is the case you should definitely match the feedline
to antenna at the antenna feed point. Any attempt to match the feedline with a
tuner in the shack only turns the whole feedline into part of the antenna
system. By doing that you have lost any good work in building the antenna.


The feedline is -always- part of the antenna system. If it troubles
you to think about matching in the shack, just think of the
transmission line as part of a matching network located at the
feedpoint. In other words, the feedpoint network is comprised of 50'
of coax and coupla LCs in a box. This network then connects to the
transmitter through a non-resonant (flat) coax line.