[brentb636]

"BTW, I'm curious what you are referring to when you say "push up and pull down", because this can do very different things, depending on what you define as up and down.
When a dish is pointed south, there is no confusion relative to what "up" means, but when the dish is motored far to the east or west, up can mean a few different things,depending on where the free play is in your system, and depending on whether you are lifting the motor axis inclination, the dish elevation (ie the declination), or are just lifting straight up from the lowest edge of the dish, which will tend to follow the arc to some extent. The way you do the pushing and pulling, ie where you are applying the pressure, and which direction you push or pull make a big difference with respect to how you interpret the results."

Thanks for the commentary, it's informative to see other opinions and the logic behind them. Another factor, at least in the case of my setup, is the weight of the Invacom QPH031 LNBF . I have read other posts that indicated the Winegard 76cm dish was better able to handle that weight than my Fortec Star. In order to optimize my "South" satellite quality level, I had to raise my dish elevation ( not motor elev ) about 6 degrees. I've wondered if that was because of the weight of the LNBF.

However, since I track lots of birds from 53W to 129W in USALS and get the expected results, I figured my rooftop aim is not bad enough to mess with. If I weren't so lazy, I'd set up ALL the birds in the sky in DiseCq motor control mode, and optimize each, but so far I don't have the time.

I do still have the suspicion that the heavy Invacom unit is not rigidly fixed in relation to the dish as it rotates and skews around the axis. It's a theoretical factor , to be sure, but it hasn't taken any enjoyment out of this FTA stuff.

Again, thank you for all your explanations.

Brent