By studying the graphs in the User Manual I have come to the following parameters, which are supposed to be good enough for CW work. Note that 80 and 40 meters can not be tuned independently, which is why the centre frequency on 80 meters is set to 3.6 MHz.
So far, I have only used the basic 16 x 4.3 meter radials but I intend to do some experiments with different radial systems in the near future. I will compare few long radials with many short ones and, of course, many long ones, too.
I have now done some SWR measurements for all HF bands, see below. The measurements were done on both wet and dry antenna. I understand it is quite normal that the resonans frequency moves when conditions change, nevertheless, it looks too crazy on 20 meters.