Nice thread! I don't know how I missed it for so long. I have that same type of old dish that I've been thinking of doing something like this to. It is really close to where my current solar array sits. I think I'll have shading in the evening during parts of the year though. Mine is mounted in concrete.
Those panels you bought are about double the power per sqft and probably per pound, as my old ones
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I'm eager to see how your panel rack (frame) turns out. Mine would need to be very similar if I wanted to put my 4 panels up.