[BC] Re: antenna trimming

[Xmitters@aol.com]

In a message dated 7/24/05 10:33:19 PM Central Daylight Time, 
broadcast-request at radiolists.net writes:

<< Unless you're using an ATU of some sort, or an LTU if it's at the
  line input end.....
 
  I'll concede you *might* need to change the transform of the Z, but no,
  it's not true that one *must* change the electrical length. >>

Cowboy:

If it is required to maintain some vertical radiation characteristic, you do 
in fact have to alter the length of the antenna, Matching for VSWR is not the 
whole picture. Even on 2 meter FM, I would not a mobile antenna that was so 
long that it had high angles of radiation; that's not where the signal needs to 
go. Of course if the frequency change is relatively small to where the vert 
radiation characteristics do not change appreciably (where the definition of 
"appreciably" being determined by what's to be accomplished) then what you are 
saying is correct.


Jeff Glass
WB9ETG since 1070