[Antennas] Running Ladder Line Through a Wall

[Cletus W Whitaker]

de WB2CPN                 2004.09.09

If the transmission line is a tuned line, as ladder
line usually is, then the effect of inserting a section
of parallel coaxial cable into the run depends upon
so many factors that the mathematical analysis is
mind-boggling.  Where the coax length is 1/8 wave
length or less and not placed at a current node the
overall loss could be insignificant.  In other
circumstances the loss could be excessive.  You'll
know, just run max power CW for a few minutes and
go feel the coax.  Worse case is if the coax causes
a complex admittance or impedance, however you look
at it, that the tuner can't handle.  Again, you'll know.
I don't usually try to protect the ladder line, just
run it where ever it has to go, under windows, through
air conditioning ducts, above false ceilings.  Just
don't try to tape it to a metal pipe anyplace.

73  Clete