Well, I bought 50ohm BNC to BNC terminated cable (1m long), I am not sure if it was for TV signal or other kind of applications but it was declared 50ohm cable. When using this cable with my low THD 10kHz sinus generator (straight from gen to scope) I noticed significant oscillation, around 82MHz imposed on 10kHz, 610mV p-p. I blame the oscillator, but when I probe the generator output with original Rigol probe, the oscillation disappeared, so the cable did induce some oscillation. I need some low capacitance coax cable (I guess) for this straight connection. I would like to ask you guys one question, (because I am a dummy). Scope has input impedance of 1Mohm. If I have a source (generator etc.) with low output impedance, can I go to scope directly without probes? In what situation do you use 50ohm termination? Thanks.