Sound like you are very close.
Which receiver are you using, the Viewsat?
Does the picture breakup, or play fine?
Viewsats are known to have Low Quality readings on FTA Sats, keeps the Round Birds from pegging the meter.
Can you connect it to the 100cm Dish to compare Quality readings?
Keep the cap bolts tightened, that pushing up or down slightly is just to giveyou an idea if either way helps the video, if so then your elevation is a little off.
If it dont make a difference I'd say you have other adjustments to look at, like maybe how well centered the feedhorn is, whether it is too far or too close to the dish (focal distance). I have a 5'dish I ran as KU only for awhile, worked pretty good I thought. Until I hooked up a primestar 1m on the same satellites I was watching, and got about 30point improvement in PQ and signal strength. I'm a believer now, in using dishes made for KU to watch KU ! Some big dishes may do a great job on ku band but others might not.
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