chas wrote:
> I am using a Cobra Senior with 100' 450 ohm ladderline run into a 1:9
> balun then into a tower antenna switch then into the shack. Running a
> kilowatt into the antenna.
>
> Routing the ladderline is a pain!!
>
> People local in the state tell me that
> 1. Ladder line does not radiate...
> 2. Ladder line does not receive...
>
> apparently all it does is provide a factor to the antenna to get the
> SWR down to a manageable amount.
>
>
> is all this a bunch of hooey??
>
> It would help me a LOT if I could either coil up about 50 feet of the
> ladderline or just cut it off. I know one operator who just tosses it
> out on the ground and has a superb signal from the Texas Hill country,
> West of San Antonio into Houston. I would try it but I still think it
> radiates and might burn my dog.
>
>
> WHERE are the facts about ladderline??
In the case of the Cobra antennas the ladder line section is important
to the operation of the antenna itself. They recommend if it is too
long or difficult to route that you coil it outside and off the ground
in as large and loose a coil as possible.
In general the advantage to ladder line/balanced line/window line is
that it has a much lower loss than coax in high SWR situations. This
is typically the case when you have a tuner at your radio then a long
run between there and the antenna. Your radio sees a low SWR because
of the tuner but the feedline may have a huge SWR.
Compare some numbers under different conditions here...
<http://www.ocarc.ca/coax.htm>
Tim, N9PUZ
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