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Mechatrommer:

--- Quote from: Electro Fan on September 01, 2020, 07:59:43 am ---- just to confirm, this was my (Electro Fan's) error caused by my mis-read on the values displayed, it was not a mis-read or any error by Mechatrommer

--- End quote ---
retested again with Leo Bodnar Pulser and built-in rT math on CH2 (no cable, direct connection from pulser to inline (diy) terminator to scope. yup confirmed somewhere 1.3-1.8ns (|AX-BX| in manual cursor). so the BW is 200+ MHz. one youtuber confirmed this as well (using -3dB FG amplitude observation) and as Fungus said, many others did too, so i'm normal ;D but when you decrease V/div to 200mV/div (in 1X attenuation setting), relay clicked and boom, 2.6ns and bad risetime (3rd pic) about similar looking to your 2072 picture @ 10mV/div


Fungus:

--- Quote from: Mechatrommer on September 01, 2020, 09:42:06 am ---when you decrease V/div to 200mV/div (in 1X attenuation setting), relay clicked and boom, 2.6ns and bad risetime (3rd pic) about similar looking to your 2072 picture @ 10mV/div

--- End quote ---

1x probes have more capacitance.

rf-loop:

--- Quote from: Fungus on September 01, 2020, 10:23:11 am ---
--- Quote from: Mechatrommer on September 01, 2020, 09:42:06 am ---when you decrease V/div to 200mV/div (in 1X attenuation setting), relay clicked and boom, 2.6ns and bad risetime (3rd pic) about similar looking to your 2072 picture @ 10mV/div

--- End quote ---

1x probes have more capacitance.

--- End quote ---

 |O First write and after then think... good practice, is it.  (even when your sentence is right itself but in context and with images you answer just :bullshit:

Mechatrommer:

--- Quote from: Fungus on September 01, 2020, 10:23:11 am ---
--- Quote from: Mechatrommer on September 01, 2020, 09:42:06 am ---when you decrease V/div to 200mV/div (in 1X attenuation setting), relay clicked and boom, 2.6ns and bad risetime (3rd pic) about similar looking to your 2072 picture @ 10mV/div

--- End quote ---
1x probes have more capacitance.
--- End quote ---
your statement is not wrong, but i guess in this case, it has nothing to do with attenuation setting in FW (FW just multiple the signal accordingly) nor a 1x coax cable. i was using the same 50 ohm termination setup (no cable), i only rotated the V/div knob (500mV/div to 200mV/div in 1X setting ie 5V/div to 2V/div in 10X setting), relay clicked and the displayed signal changed, same input signal setup, no change. i highly believe its the signal paths difference inside the oscilloscope.

David Hess:

--- Quote from: Mechatrommer on September 01, 2020, 09:42:06 am ---but when you decrease V/div to 200mV/div (in 1X attenuation setting), relay clicked and boom, 2.6ns and bad risetime (3rd pic) about similar looking to your 2072 picture @ 10mV/div
--- End quote ---

Look very carefully at the area from 1 to 3 nanoseconds after the trigger in your last image; the shape of the pulse edge changed!  And it became very straight which indicates overload or cutoff of an amplifier stage due to excessive slew rate, so the full power bandwidth is not sufficient to support 100 MHz operation.  The full power bandwidth matters because at 200mV/div, the relay click you noticed removes the high impedance input attenuator and applies an order of magnitude more signal to the input stages.

Older 100 MHz oscilloscopes with *faster* transistors maintained an order of magnitude less signal at the input stage by including more input attenuators to control signal levels and not surprisingly, delivered consistent performance at all input attenuator settings.

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