I assume you mean 8116A (not 8116).
The 8116A can make it to 50MHz.? But it has a specified rise/fall time of <7ns (I measure 5.6ns on my unit), so this will make square and triangle waves look like sine waves by the time it gets to 50MHz since it's spending the majority of the time transitioning.? At 50Mhz I also have some minor reduction in peak-to-peak levels (like 10-20%).
Are you using 50 ohm termination on your scope to view the output?
Unless what you're seeing is severely distorted, a lot of this can be tweaked with adjustments, but having done the adjustment procedure a couple of times I can say it's a bear to get it right.? Many potentiometers are overly sensitive to movement, some adjustments interact with each other, and most are a compromise of what looks least bad.? Be prepared to spend the better part of a day.
Can you post some screen captures/photos of the 8116A settings and waveforms you're seeing?
-mark
