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Mr Moose · 5th Sep 2010, 12:22 pm

Hello,
Towers gives the minimum Hfe (Common emitter current gain) for each type as follows:-

OC71 30 (minimum) @ 5mA bias

OC81 50 (minimum) @ 100mA bias

OC81D 20 (minimum) @ 5mA bias

I think there can be quite a variation in gain with different transistors of the same type.

Yours, Richard

5th Sep 2010, 12:22 pm	#4
Mr Moose Octode Join Date: Jul 2008 Location: Gloucestershire, UK. Posts: 1,043	Re: Transistor Choice in radio project Hello, Towers gives the minimum Hfe (Common emitter current gain) for each type as follows:- OC71 30 (minimum) @ 5mA bias OC81 50 (minimum) @ 100mA bias OC81D 20 (minimum) @ 5mA bias I think there can be quite a variation in gain with different transistors of the same type. Yours, Richard Last edited by Mr Moose; 5th Sep 2010 at 12:32 pm.