What voltage did you use?
What resistor value did you use?
What was the Vds while the Id was passing?
What resistor value did you use?
What was the Vds while the Id was passing?
9V from battery and 1.3 volts drop through the resistor leaves just 7.7V across the jFET.
It will under-read at this low Vds. Idss is measured at 10Vds.
1.3V might go as high as 1.35V at the full test voltage.
That puts it far enough beyond the 12mA maximum of a BL to be concerned.
Measure the Vpinch-off and from there determine the gm and compare to specification.
It will under-read at this low Vds. Idss is measured at 10Vds.
1.3V might go as high as 1.35V at the full test voltage.
That puts it far enough beyond the 12mA maximum of a BL to be concerned.
Measure the Vpinch-off and from there determine the gm and compare to specification.
Sorry that I'm not good in electronics. Does this mean I need to use higher voltage to measure it?
If you need to be reassured that your devices are within specification, then you need a bit more accuracy in your method of measurement.
Idss is measured with Tj=25degreesC, when Vgs= 0 and Vds = 10V
If you accept that they are all close enough, then using 7.7Vds is OK.
You/me cannot exactly replicate the manufacturer's method, particularly Tj.
Idss is measured with Tj=25degreesC, when Vgs= 0 and Vds = 10V
If you accept that they are all close enough, then using 7.7Vds is OK.
You/me cannot exactly replicate the manufacturer's method, particularly Tj.
After long sourcing the parts, finally I managed to get all the parts.
This is the picture I almost finish. Please check is this correct? I'm a newbie here and I don't know much about electronics. I can't find much info/pictures here.
The parts I left out at the moment are C203 (10uF), 2SK170 and 2SJ109. I managed to get some 2SJ74 which I heard it can be parallel together, but how do I parallel it? Is there any diagram I could refer to? For example the leg arrangement.
This BA1 I would use as a pre. After long reading this post, I notice that R207 will leave it empty and the variable resistor need to be changed to 1k, correct?
This is the picture I almost finish. Please check is this correct? I'm a newbie here and I don't know much about electronics. I can't find much info/pictures here.
The parts I left out at the moment are C203 (10uF), 2SK170 and 2SJ109. I managed to get some 2SJ74 which I heard it can be parallel together, but how do I parallel it? Is there any diagram I could refer to? For example the leg arrangement.
This BA1 I would use as a pre. After long reading this post, I notice that R207 will leave it empty and the variable resistor need to be changed to 1k, correct?
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