Testing hFE, "I" reading?

[nihoneiga1960]

Hi there,

Recently I acquired a DMM that has a little socket for testing transistor hFE for NPN and PNP trannies. I was going through and checking the ratings of a bunch of transistors I have in search of some suitably low hFE for a fuzz pedal and I noticed I was getting a lot of "1" or "I"(infinity?) readings, meaning there was not reading just something saying "1" or "I" for a bunch of NPNs I've got.

Why could I be getting this reading?

[bone]

Usually this means that the transistor is:
- shorted collector to emitter or
- that it is high leakage or
- the gain is very high. (over 1000?)

You can often get this reading with Germanium transistors as the leakage current is high.

Tony