Can't see the back side of the dish, but I'll bet there's a place you can stick in inclinometer.
I wouldn't want to take a 12' board up the middle on the front side, just to check the elevation.
The mount being plumb may not really matter much for fixed operation (more critical if you're motorized).
That knob below the feed looks like your skew.
Maybe you pull down on the lanyard, then twist the knob half a turn at a time (?)
Suspect it'll be obvious to ya, once you play with it a bit.
For the dirty middle of the dish, I'd go with a power wash.
Some guys have discussed a stiff brush, hot water, soap, and maybe a little bleach for cleaning.
You've already got an orthomode feed (two LNBs, one for each polarity).
And a fancy matching scalar.
Life doesn't get much better.
Not sure how to clean it, though. Kinda have a similar problem myself.
Depending on your intentions, you might go with inexpensive LNBs like these from
Galaxy Marketing.
Think HyperMegaSat is one of their dealers (unless I am corrected).
Or, you could invest in higher quality
Norsat 8515 LNBs, such as these.
Considering it's a 12' dish, and not motorized, I might just go with the cheaper ones.
Yes, you need two.
To hook the LNBs to your receiver, most folks use a multiswitch, like a 2x4, or 4x4.
Pendragon described a
very nice 4x8 that is very cheap (see the thread).
While it may seem overkill, it was the cheapest solution I could find.
The mod gives 18 volts to both the V and H LNBs for best performance.
You can try an unmodified multiswitch at first, and see if the Vert transponders seem compromised (should still work).
Even a lowly $5 surplus 2x2 multiswitch would be enough, but stumbling over one is less likely.
