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100G -1000G Resistors

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magic:
Not sure what sort of circuit this resistor goes into, but Johnson noise and stray capacitance may make significantly faster speeds infeasible anyway, so the customer may simply need to adjust his expectations.

TimFox:

--- Quote from: magic on May 14, 2023, 03:26:08 pm ---Not sure what sort of circuit this resistor goes into, but Johnson noise and stray capacitance may make significantly faster speeds infeasible anyway, so the customer may simply need to adjust his expectations.

--- End quote ---

The article I linked above goes into great detail about optimizing the speed of a sensitive electrometer circuit with these resistors.

TimFox:

--- Quote from: jwet on May 14, 2023, 02:16:35 pm ---Tim Fox- I could be wrong about who made Victoreen R's- I was told this somewhere along the line.  Victoreen had a lot little specialty shops in that big place near Shaker Heights.  There was a little shop for making those view through electrometer based dosimeter pens, quite an operation- saw it around 1986.

--- End quote ---

I looked at the BOM (1977 manual) for my Keithley 261 Picoampere source (precision voltage source driving selectable high-value resistors), designed to calibrate electrometers.
The "deposited carbon" resistors have manufacturer's code 80164 (Keithley), but that may be since Keithley measured them individually for calibration.

jwet:
Tim Fox- I just started digging into that 1965 Article- thanks very much!  You're kind of on your own with a lot of this esoteric stuff.  Keithley made a low level measurements handbook that is very good too and I have it but its more about appplications (selling instruments) than design.

jwet:
Magic- I agree, I think they're hoping for >5 per second for pot tweaking or other adjusting.  At these currents, you're getting down to statistical currents sort of like shot noise.  I'm in the proposal and discussion phase now- I haven't got a contract yet.  I have to be fairly polite still...  I might pass- I have a week to decide.

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