Topband: Changes To My Shunt Fed Tower

[Bob Garrett]

Hello Topbanders,

It is getting cold in the Northeast and as I get older, I dislike the cold
even more.

In April of this year, I replaced my Cush craft D40 40 meter rotable dipole
with an OptiBeam OB-4030 dipole for 30 and 40 meters right at the top of the
mast.  The overall length of the antenna is about ten feet longer and I am
assuming that it has added some additional capacitance to my 100 foot shunt
fed tower with a Cush craft X7, A3WS, 5 EL M2 6 meter yagi and the new
OptiBeam dipole.  

My match on the tower went from 1.0 x 1. To 1.9 x 1 after I installed the
new antenna.  In terms of loss, this isn't a huge change but my amplifier
doesn't like the change.  Before I spend a lot of time running back and
forth to the tower making random changes, any thoughts as to what I can do
to improve the match.  I'm currently using one series capacitor 1000PF for
the matching network.  I have attempted to adjust this capacitor but it
looks like the 1.9 x 1 is the low point.  Perhaps some thoughts - increase
or decrease the spacing of the shunt wire?  Move the connection up or down
on the tower?  

Before I get to crazy, just wanted to look to the base of knowledge on this
reflector for your input.

73 and tnx in advance.

Bob K3UL