[TenTec] [Fwd: Line Isolator Balun (sorta) question.] Sorta OT philosophy, or where does it get us?

[Stuart Rohre]

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