[Johnson] Ladder-line mounting question

[C Eus]

I suspect that it really isn't an impedence bump that is the concern but rather the absorbtion of the rf by these bicycle hooks. If it is any consolation, I ran a similar configuration using twin lead that fed a dipole and the balun output to my Johnson Matchbox, but the leads were taped to a set of segmented Radio Shack T.V. antenna masting. Apparently, the signal got our find but if I were to do it over again, I'd use standoff insulation to keep the twinlead from the metal masting. FWIW, Cal, N6kYR/8

John Lawson <jpl15 at panix.com> wrote:

Just got my fence-perimeter NVIS loop installed yesterday (thanks to 
the kind slave-labor assistance of Brad, KB7FQR). I'm using 450-ohm 
feedline from the loop back to the tuner in the shack. It comes thru a 
hole in the shack wall and I had planned to suspend it along the rafters 
on those large 'bicycle hooks' for the 20 or so feet from the entry point 
over to where the Gear all lives.

It has been suggested that this is a Not Good Thing - that any metallic 
object like that touching the ladder-line will alter the impedance, stress 
the insulation, etc.

I can see the insulation concern, but I don't get how a pice of 3/8ths 
steel rod covered with plastic at right-angles to the feedline conductors 
can make much of an impedance bump.

So I thought to solicit the general wisdom of those of us who might know 
the real 411 on this subject, because I'm not the brightest bulb in the 
marquee when it comes to HF antennae and feedlines.



Cheers

John KB6SCO
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