[Elecraft] KAT100 with Ladder Line

Joe-aa4nn aa4nn at earthlink.net
Sat Nov 17 10:56:56 EST 2007


It can be quite tedious to build one's own ladder line.  Wire size and
spacing between wires is a critical factor in determining the resulting
impedance of the line.  Maintaining consistent spacing between wires
is difficult.  For closely spaced wires (eg. 1.5 to 2.0 inch for 450 ohm)
slight variations in spacing is very critical to maintaining consistent
impedance; whereas for 6 inch spacing there is less effect on impedance
with slight variations in spacing.  Eg. 6  inch spacing using #12 wire will
give approximately 600 ohm open wire feeders.  More info at:

http://www.cebik.com/trans/par.html
http://www.cebik.com/gup/gup31.html

I find lexan difficult to cut due to the low melting point and clogged
saw teeth.  Plexiglass is a little bit better.  I would opt for the smallest
PVC pipe, cut into 6.5 inch lengths.  Cut a 1/4 inch depth notch in
either end wide enough to accept #12 wire.  Use a band saw, scroll
saw or hand held saber saw.  After inserting the wire in the PVC,
put a dab of Marine Glue and Sealant on there, or other quick drying
adhesive.
de Joe, aa4nn 



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