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
Biasing JFETS
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
LCR-T4 ESR Meter LCR led Transistor Tester Diode Triode Capacitance MOS PNP/NPN 664869130256 | eBay
A very thorough article and very well written and easy to understand as well.
Thanks for posting the link.
Thanks for posting the link.
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.
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.
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.
and then tested. Ideally use a multi-position switch with the devices covered from air currents.
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.
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.