I have a Keithley 26300 Logarithmic Picoammeter that functions but needs repair.
There are nine variations in the Keithley 26000 series:
[positive, bipolar, or negative input] x [(10^-3 to 10^-11), (10^-4 to 10^-12), or (10^-7 to 10^-13) amp range] = 9 choices.
My unit has positive input current, with (10^-7 to 10^-13) amp range.
I have a manual for the Keithley 26220, which is bipolar-input and (10^-4 to 10^-12) amp range, and also a working 26220 meter.
I believe I need to change a factory-set fixed resistor in the log amp offset adjustment, but I don't have the exact wiring diagram for the positive input versions. The bipolar-input versions all have positive outputs for both polarities, but my positive-input unit has a negative output, which is not possible with the wiring diagram used for the 26220.
The usual sources (including Keithley's website and those in the sticky here) don't have the 26300 manual available.
Can anyone help me find the wiring diagram for this unit?