[Elecraft] KX3 and Solar Panel

[Greg Troxel]

A 20W panel that is labeled as for a "12V" system will typically have a
Voc (open circuit) of 22ish V, and a Vmp (maximum power voltage) of 18V.

Generally, one should not hook up a bare panel to a load, and the usual
recommendation is charge controller and battery.   I wonder about a
large cap instead of a battery, enough to make the controller stable.

I have a 20W (HQRP) panel and use a Genasun GV-5 MPPT charge controller and
then charge about 100Ah of batteries.  I have not tried the controller
with no batteries.

The anyvolt3 is an interesting concept for this application.  MPPT
controllers try different voltage/current combinations to find the one
that's in-range for the DC-DC converter and results in maximal power.
I have found that to be around 17.5-18V whenever I get more than 200 mA