Colin wrote:

The power supply for this radio is a 175 watt inverter powered from a 12
volt battery, which in turn is charged by a set of solar panels, the charge
from which is regulated by a Morningstar Sunsaver charge controller. If I
unplug the radio from the inverter and plug into the regular power supply
from the grid, the noisy signal becomes clear. Additionally, after I unplug
from the inverter, for a second or so as the fields in the system die down
the signal becomes clear before the radio stops working.

This seems to indicate that the antenna is ok, and that the interference is
in the solar system somewhere, but not the inverter (otherwise the night
time reception would be bad) but perhaps the charge controller is having an
effect on the Trisonic amplifier?

I'm guessing that the inverter or charge controller are throwing out RF noise
that's interfering. Since it's "heliotropic," maybe the latter. Have you
tried unplugging the solar cell from the charge controller during the day and
seeing if it clears up? If not, give it a go and see what you learn...