The hoorah about RF on the outsde of the coax is much less a problem
now that we have gone to Digi TV and cable services for the most part.
At least in respect to TVI.
It only affects your received antenna pattern, and possibly not
detrimentally. I say that because, at any one time your antenna, no
matter how pure in orientation, may have both vertical and horizontal
responses, thus picking up or radiating off the vertical part of the
feeder may not change performance all that much. It "might" allow more
noise pick up, certainly. On transmit, you may have some signal go off
at an angle that is not the primary angle of the majority of radiation
from that antenna, but likely the loss would not be heard by the station
at the other end. What may make it tricky, is the length of feeder you
must have to reach the rig.
There have been many accounts of successfully feeding dipoles with coax
and no balancing devices at the antenna center or at the shack. It is
likely the effects are such, the casual operator cannot measure them
without instruments.
It is probably safe to say most home station hams are not end feeding
random wires since all the attention paid to SWR in recent times, is
most easily satisfied by use of an almost universal tuner or resonant
antennas close to their optimum points. There is likely more concern to
have an antenna that is purpose built to perform on the given band in use.
Yes there are many ideas in ham radio. In a way, that is the fun of it,
to try things others say improve your situation, and if it does not
help, or is neutral, go on to something else. Identify the science in
the antenna analysis of persons like L. B. Cebik, W4RNL, who used
modern modeling methods to exhaustively test antenna ideas on the
computer. In RF authorities like the text book "Reflections", (now vol.
III). On the web sites of
scientists like W8JI, (many topics much good stuff), and N6LF,
particularly in the matter of radials for verticals see
<AntennasbyN6LF.com>. There are many more. Get the texts of the
college masters,
starting with the classic "Antennas" 2nd Ed. by W8JK. The basic EE
texts help to establish the science and fact. With those as a
reference, you can judge the rest.
The Ten Tec radios operate best with a well behaved feedline-antenna
combination, and they will complain when something is loose, or not
right with any of that system that gets your power to where you have
directed it.
-Stuart Rohre
K5KVH
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