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Matching a large number of jfets - best howto
Matching a large number of jfets - best howto
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Old 22nd November 2019, 08:54 PM   #21
adason is offline adason  United States
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I have been using this simple test rig, Fig 9. All on breadboard, with connectors for fresh batteries and sockets for transistors. And two multimeters.
Biasing JFETS
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Old 22nd November 2019, 08:58 PM   #22
adason is offline adason  United States
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Other option is one of these cheap chinese test meters. While I do not know exactly what voltages they apply, and what are exact conditions of the measurements, they are consistent, acceptable for matching.
LCR-T4 ESR Meter LCR led Transistor Tester Diode Triode Capacitance MOS PNP/NPN 664869130256 | eBay
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Old 22nd November 2019, 09:02 PM   #23
gary s is offline gary s  Australia
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A very thorough article and very well written and easy to understand as well.

Thanks for posting the link.
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Old 23rd November 2019, 12:11 AM   #24
woofertester is offline woofertester  United States
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I use a Keithley 2602 System Sourcemeter that I scored being at the right place at the right time.

It allows me to characterize just about any semiconductor that will be used in a piece of audio gear.

If I did not have this I would use a two channel power supply and two or more DMMs. All of them would have to have remote control capability. Writing the software would be a chore.

On the to-do list is some software controlling a mini printer that will create the measured parameters on receipt sized paper to be stashed with the device in a small zip lock bag.
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Old 23rd November 2019, 12:32 AM   #25
rayma is offline rayma  United States
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I would test larger quantities with all devices (or a reasonable number) powered simultaneously, warmed up long enough,
and then tested. Ideally use a multi-position switch with the devices covered from air currents.
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Old 23rd November 2019, 01:42 AM   #26
aspringv is offline aspringv  Australia
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Matching a large number of jfets - best howto
Thanks everybody, and particularly John and Nelson. I'm flattered that you'd both take the time to share your insights.

OK, well I reckon I'll get on with it with the parts I currently have and get a gauge on time, process and end sale price, and see if it all makes sense to do a lot more.

Thanks again everyone, I'll update there after I get a few things done.

Cheers! A.
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