View Single Post
  #2   Report Post  
Old July 8th 09, 03:57 PM posted to rec.radio.amateur.antenna
Tim Shoppa Tim Shoppa is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 263
Default Twin lead versous Ladder LIne:

On Jul 8, 9:52*am, "Howard Kowall" wrote:
Hello to all
Going to build a Mystery Antenna *to take to the lake for 2 weekshttp://www.w5gi.com/mysteryantenna.htm
It says to use 300 or 450 ohm window line.What I am asking if there is *a
real big diff *if I use 300 Twin Lead.
I realize that the power handling capacity is reduced,but I will be only
running a max of 100w for a short duty cycle(not a big talker).
And I also realize that it is not mechanically as strong.Has anyone have
some thoughts on this.
I will be using a manual tuner on this type of antenna.
Thanks to all in advance
Howard
VE4ISP


TV-type twin lead will in general have markedly worse characteristics
when there's water on the line. 100W won't be a problem until moisture
soaks in.

There are several different types of ham window line with different
gauge conductors and solid vs stranded. Copper-plated-steel window
line like sold by Wireman and others has a handy property: it
remembers that it was originally coiled which can help with stowing it
for portable/occasional use. Handle it wrong and it'll wrap around you
like a cobra :-).

True ladder line (all empty space except for spacer rods) will be
superior to either twinlead or window line.

Any antenna beats no antenna, so don't fret the details too much in an
effort to perfectly clone someone else's setup. Just getting any wire
into the air and loading up into it ought to be the first goal, not
making the pefect clone of someone else's mystery antenna.

Tim.