View Single Post
  #4   Report Post  
Old April 11th 06, 12:40 AM posted to rec.radio.amateur.antenna
ml
 
Posts: n/a
Default vert distortion?

In article ,
Wes Stewart wrote:

On Sun, 09 Apr 2006 13:18:18 GMT, ml wrote:

hi


i've noticed a few installations of say a 2m beam vertically mounted to
a regular metal tv style mast

from looking at it, you have the mast(metal) going between 2 elements
and longer than the elements

so i was wondering as this is a common mounting style and method

how bad is the beam pattern for rx and tx ? effected by the metal mast?



it also got me thinking i've noteced some beams as in the above use a
fiberglass boom while others use metal

how does this effect patterns and efficiency

both from a practical point of view and technically speaking


The metal mast affects the performance to some degree, but I don't
know of a rule of thumb for predicting it. So the answer is, it
depends.

A fiberglass or other non-metallic mast will help, it you also use a
non-metallic coax line.





???


thanks


thanks for the interesting reply's , i was originally wondering how it
would negatively effect it, which is my concern and knowing in what ways,

but the j pole thing got me sorta thinkn' once i know the downside
specifics' perhaps i might be able to turn it into a good thing??

cool