Topband: shunt fed tower (was: How to measure the resonance of a tower)

Guy Olinger K2AV olinger at
Thu Jan 20 10:46:36 PST 2011

You should probably have a conversation with SteppIR about being the top
antenna on a tower that is being loaded on 160.  I really don't know what
they recommend.   BUT, if you are QRO there are many kV of RF trying to find
the next best path to extend, and the capability of arcing and creating
destructive carbon paths that will take expensive repair to remedy.  Perhaps
the boom is bypassed to the center of the forward and rearmost elements.  I
don't know, but you should establish that with engineers at SteppIR.

73, Guy.

On Thu, Jan 20, 2011 at 11:47 AM, DM4iM <hamradio at> wrote:

> Topbanders,
> today i found that i need to ground both legs of my ladderline that
> feeds my dipole to make it sort of invisible to the vertical.
> Now, the swr-curve changes are small when i lower the dipole,
> but i still don't get a match.
> I had a discussion with a guy who has a similar setup as i have, he said
> the capacitance of the SteppIR is too small because the
> parasitic elements are floating. They are not connected to the boom,
> so they don't contribute to the tophat.
> Does anyone have a better idea than to bond the parasitic elements to
> the boom?
> --
> 73,
> Martin DM4iM
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK

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