"Reg Edwards" wrote in message
...
I'm not quite clear what you are talking about, but the impedance seen
looking into the feedpoint of a 1/2-wave resonant dipole when the
feedpoint is at the centre, is a purely resistive 70 to 73 ohms.

As the feedpoint is moved away from the centre the impedance rapidly
increases (approximately proportional to the square of the offset) BUT
REMAINS PURELY RESISTIVE until, as the feedpoint nears the end of the
dipole, it rises to several thousand ohms, purely resistive.

This is the impedance which terminates the twin feedline. But if there
is a choke in the line at this point then the choke can be considered
to be a short length of line of the same length and Zo as is wound on
the choke.

The short length of line on the choke will then TRANSFORM the antenna
input impedance to a somwhat different value to terminate the line.
(For the purpose of calculating SWR on the line, and the line's input
impedance, etc.)

Now carry on from there. ;o)
----
Reg, G4FGQ

Thanks, Reg, for sharpening up the picture on off-center feeding of a wire
antenna. And thanks, Roy for bringing out the likelihood of asymmetrical
coupling to the off-center feedline and the difficulties that can result.

73, Chuck W6PKP