Built up a test jig for sorting thru the bunch of MRF150 devices I have here and thought I would put up a schematic in case anyone else is interested. With two power supplies, one for the drain and a variable for the gate, you can get an idea for the current gain by comparing gate voltages for a given drain current. Also lets you know if the device is shorted because the light will light brightly or if the device has high leakage from drain to gate or is open. The switch forces the gate to ground to see leakage and cut off the device under test, also I feel better killing the bias line before messing around with the gate line anyway.
It’s built on a old amplifier from a MRI machine, who would have thought that a MRI would use both MRF150 and MRF148 devices? Bought the panels to strip the devices but they also provide a good source for the jest jig.
If there is additional interest may have to do a video!
FETjig.jpg