Thanks for response Reg, here are a couple of follow up questions:

Reg Edwards wrote:

Zeno, In answer to some of your questions -

For multi-band working, ladder-line or preferably open wire line is almost
essential.

Overall antenna length is very non-critical. When using a tuner you can be
many feet adrift from the theoretical calculation without any degredation in
performance. A change in length affects only the radiation pattern which
for practical purposes can be considered omni-directional anyway.

For multiband operation be prepared to make relatively small changes in
length of feedline as part of tuner operation.

Are you saying that every time you would switch bands or frequencies, one might
have to change length of feedline? I am trying to picture that, is there some
convenient solution to this process?



Use a simple choke balun at the transmitter end with a balanced feedline.
Make no attempt with a voltage-ratio balun to match feeder input impedance
to 50 ohms. Leave that entirely to the tuner.

A choke balun for 160 meters consists of a 1.5" to 2" diameter ferrite ring
wound with 8 to 12 turns of 18-gauge flexible speaker cable, or similar.


Just to make sure we are on the same page he are you saying to use this
choke balun just for operation on 160m if I want to use my Kenwood tuner? I am
assuming that when using the Johnson Matchbox for the bands it was designed for
I would connect the feed line directly to the Matchbox terminals, and that
feedline would connect directly to the antenna (no baluns, no chokes, or
anything).



A coax feedline means lossy operation on other than the fundamental
frequency.

A balanced feedline near to phone or power cables will cause no trouble
unless nearly touching over a long distance.
---
Reg, G4FGQ