[Elecraft] K2 ATU and 43-ft Vertical

[Phil & Debbie Salas]

"The base loading coil is nearly identical in design to the toroidal
coil of AD5X, linked below.  I do intend to find 160 & 80m tap
locations for the antenna."

FYI - The maximum power I've run with my 43-foot vertical and matching 
system is 1200 watts with no problems experienced for several months.  But 
then one humid morning the unit did arc from the output connection across 
the electrical box to a nearby ground point (you could see a nice carbon 
trace across the box).  The SWR jumped suddenly and the amplifier (ALS-1300) 
tripped out like it should.  I replaced the output screw with a ceramic 
feedthru and haven't had the problem since.  As Tom W8JI stated, the 
voltages can be extremely high especially if you are running high power.  If 
you run an amplifier, I'd recommend using a ceramic feedthru output, and 
keep the output port several inches away from any ground connections.

Phil - AD5X