You could also remove the protection diode and other components paralleling the 1 meg input resistor to further reduce the capacitance, but you might run into inadequate adjustment range for the attenuators as they are switched into the signal path.
If the aim weren't to just use another probe, or another vendor's probe, you could go active to reduce the tip capacitance loading.
Or go 100X <grin>.
As others have noted, though, probes for the 2465 were peaked up to accomodate the full bandwidth at the tip and even Tek probes, other than the (at the time) P6131 didn't work for beans on the 2465.
Joe Rooney
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--- In TekScopes@..., Geoff Blake <geoff@...> wrote:
On Thu, 28 May 2009, hankc918 wrote:
You cannot "change" the input capacitance of any Tek vertical input.
It is what it is.
Use a Tek probe.
HankC, Boston
Err, what exactly does the calibration of input capacitance do then?
If you have a 'scope with input impedance of say 20pF in parallel with
1Meg, putting a parallel resistor capacitor of 1Meg/20pF in series with
the input (exactly the same as an input normaliser) will change the input
capacitance to 10pF, and resistance to 2Meg.
It will also upset the calibration...
Geoff
