[TowerTalk] Tune 160/80 Vertical

[Jim Brown]

I really like the method Jim outlined here -- I've been using it on my 
Tee vertical ever since I moved to W6 ten years ago!  I use a parallel 
combination of small doorknob caps to tune it.

73, Jim K9YC

On Sat,11/20/2010 6:51 PM, Jim Thomson wrote:
> ##  Install  a  capacitor in series with the feedpoint of the vertical, right at the base. Make the horizontal wire long enough, so the resistive component is  50-60 ohms on the freq you are interested in.  At that point you will have some XL.   Then tweak the cap  so the Xc of the cap  will cancel out the XL  on 160m.  Presto, flat swr on 160m.    On 80m, the cap  has to be shorted out.  No big deal with a suitable spst relay.
> A buddy used a motor driven  2500 pf cap... and a 100' tall  vertical, with an inverted vee type capacity hat on top.   This entire mess  was  suspended on a catenary line, between 2 x trees.  It's flat swr across the entire 200 khz.
> Note, on some vac caps, they have a feature on em, whereby when the cap is fully meshed, and then some, the plates  will  short out.   This saves you having to install a relay across the cap, in cases where you want it shorted out.... as in your dual band set up.
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