Got this scope the other day off e-bay. It was sold as deffective, and eventually showed up as DOA. Fortunately it was only a blown fuse and some corrosion in the internal PSU connetor, so the scope came alive.
I started to check the rise time performance of the scope with my pulse generator. This generator has vague rise time specifications (only says <1ns), but at work we measured with a LeCroy 4GHz scope to be 425ps.
So with this generator I got nearly identical rise time results on CH3 and CH4 around 600ps (which is quite nice from a 500MHz scope...
)
CH2 on the other hand has some sort of under damped behavior, so the resulting rise time is around 1.2ns, and is basically independent of V/div setting as I saw
There is a sticker on the front panel stating CH1 50 Ohm termination is open, and it is indeed open, however using a Tee adapter with an external 50 Ohm terminator it shows similar rise time as CH3 and CH4.
Is there a way to adjust the compensation of the attenuator on CH2?
See picture below, from top to bottom CH4-3-2-1