Hello,
When I have a pulse generator into channel 1 thru a 50-ohm feedthru I see a damped ringing on channel 2 (1/delta-t ~190 MHz) even though I don't have anything hooked up on channel 2. When I hook up a PMT to channel 2 thru a 50-ohm feedthru any response from the PMT is obscured by the ringing. Actually, with just a 1.5 ft SMA to BNC cable (DC-3GHz, 30pF/ft) connected to channel 2, the amplitude of the ringing about doubles. Is something wrong with my scope or is it something else?
Thanks, Tony