[Antennas] Ladder line use with beams

[Sandy and Kees Talen]

I'd like to ask some opinions on this.....	

I have a 250ft run to the HF beam and typically drive at 
150W or less. Since low loss (and low cost) is desired,  
I settled on a long run of 450 ohm ladder line through the 
trees, smooth long radius bends (most through radiator 
hose where it touches something, etc. An antenna tuner 
is used at the Tx/Rx end.

At the tower, it runs through pieces of PVC spaced 12" out 
from the tower with plastic stock and  20 ft apart (55ft tower). 
At the top it runs through a "loop" of smaller heater hose to 
get around the rotor and is tied directly to the beam. Seems 
to work fine. I was going to use a 9:1 or at least a 4:1 balun 
at the beam end (or at least so I could get around the rotor 
with coax) but figured that the mismatch wouldn't affect
anything because of the low IR loss in the ladder line and 
I could always match to the Tx with the tuner.....so I tied it 
directly to the beam. There may be some substantial
voltages developed at the beam end (and ?) because of the 
mismatch.  What else do I need to look for ?

Any ladder line is affected by moisture, I've heard that open 
(4"+ spacing) is not. Any verification of this ? What is 
a good cheap spacer ? ...light, cheap, easy to rework, stable, 
easy to attach, strong, low wind resistance. 250 old BIC pens ?
...just kidding. I'm not boiling wood sticks in hot parafin with 
PVC available. 

Comments ?


73s  Kees K5BCQ