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Radio Wrangler · 13th Apr 2021, 11:17 pm

Even the '4416 FET has quite a wide range of Idss, so it may be that these probes used selected parts.

Those small pill packages were quite common in the day but needed a hole in the board and careful fitting. Is there a variant of a possible device in the smaller SC70 package... like a little SOT 23.

This looks fixable with a bit of hunting and care.

Oh, and that capacitive divider trick for waggling the drain voltage to null some of the gate capacitance is pure evil. Wish I'd thought of it!

David

13th Apr 2021, 11:17 pm	#2
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Tektronix P6201 FET Probe repair Even the '4416 FET has quite a wide range of Idss, so it may be that these probes used selected parts. Those small pill packages were quite common in the day but needed a hole in the board and careful fitting. Is there a variant of a possible device in the smaller SC70 package... like a little SOT 23. This looks fixable with a bit of hunting and care. Oh, and that capacitive divider trick for waggling the drain voltage to null some of the gate capacitance is pure evil. Wish I'd thought of it! David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done