[TowerTalk] More on trimming the 75 ohm hardline

[w8ji.tom]

> I understand where 1.808, 3.601, 7.213, 14.43, 21.65 and 28.88 MHz are
coming from (even harmonic multiples of the basic half wave length, in this
case corresponding to 1.808 mHz). 5.401 mHz must then be the 3/2 WL point,
correct? This would be consistant with the other phenomenon of the series
of frequencies above:

The low Z point occurs at ANY multiple of 1/2 wl, not just even or odd
multiples.

Since SWR bandwidth of the feedline is narrowest at the highest frequency,
we are often better off to fine tune the line for the favorite freq on the
highest band used and live with the rest. But first ALWAYS trim a bit long
on the lowest band!
 
73 Tom

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm