I recieved this from a helpful gentleman named Димитър Димитров ---- Measuring of germanium transistors with digital multi-meter may be very inaccurate due to several reasons. Our engineer Mr. Plamen Vasev (firstname.lastname@example.org
) has invented a new method to check quality of germanium transistors via two measurements of the base current. With this we calculate the gain and also can conclude for what the measured transistor can be best used. 1. The leakage current Icbo is measured first. 2. Then the base current Ib is measured at fixed collector current Ic (eg. at 0.5 mA, fixed by a resistor connected to the emitter). 3. Finally the gain hfe = Ic/(Ib+Ibco) is calculated. Example: If Ibco=4µA, Ic=1000µA, Ib=12µA, then hfe=62.5 If this example transistor was measured with a digital multi-meter it would show a figure about 100!! or about 60% error!!!???
Best Regards,Dr. Dimiter Dimitrov Manager BgEbus Is this method different than the one you longtime EE typed have been using?
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