As an aside, I wonder if this is proof that a shunt feed tower is no
good??? I can SEE the tower (runway) over the nose of the airplane
at 15 miles out! yet the RMI indicator is wandering! The beacon
ID is in the noise!

I get a good match but the band width is NARROW! this indicates to
me that the Q is high just as it should be? the RF amp meter is
showing current thru the vertical run up the tower face if your
careless around the 2300 pf vac cap you get a nice RF burn.

By the way, I made a mistake, I am using an omega match the values of
the caps:

C-1 500 pf ( from 50 ohm coax center conductor to 2300 PF Vac Var
cap )

C-2 2300 pf vertical wire run thru C-2 2300 pf cap then ground


thanks!!!!

I have just run a preliminary NEC model. I am showing a gain of
-9 dBi at an elevation angle of 10 deg. at 530 kHz. Directly overhead the
gain is about -26 dBi. A typical matching network should
have a loss of about 4 dB, for a TRP of around 1 W or so.
The input impedance will be about 0.2+j176. You should have about
10 A RMS in the base of the gamma match vertical wire and, 1.7 kV RMS ,
assuming a 4 dB loss in the matching network.

My model needs some refinement, but should give a ball
park idea of what to expect. I did not understand exactly how you
are using two capacitors to match the antenna.

Regards,

Frank (VE6CB)