3AX31C hfe

[rankot]

I have a few of 3AX31C transistors, so I tested them with transistor tester. They're all PNP, but hfe range from 60 to 427(!). Is it really possible that Ge transistors have such a big hfe, or those are some kind of fakes?

[tonyharker]

How did you test them?  Its likely that the higher gain ones have high leakage.

[italianguy63]

I've had them in the past... I think they were Chinese manufacture.

They were usually high gain and high leakage.

(makes a cool narley fuzz)

MC

[mcknib]

I've got a few old RCA 2N2613's with hFEs from 240 to over 360 all with very low leakage

So it's defo possible to get big hFe's with PNP Germaniums

I was kinda thrown a wee bit too so asked Jon @ acidfuzz about them

Hi Billy,

The RCA 2N2613 is kind of an oddball germanium. It has the highest gain of just about any I've seen, but they also typically have very low to moderate leakage, which is a little counterintuitive for gains that high.

All of my RCA 2N2613 measure between ~165 to 300, with a current leakage of ~.02 to .12 mA at ~73 degrees F.  So, 350+ Hfe is a bit high, but your measurements may be off, or you may have a different year/batch. Even well respected brands like RCA & Mullard have inconsistencies between batches where the specs will be slightly different from proior and later dates of the same device.

Nice guy Jon

[rankot]

hFE 450 - ICE0 240uA
hFE 200 - ICE0 40uA

So it seems they're fine. Measured with GM328A transistor tester.

I've already built Tres Hombres fuzz with them and it sounds nice, real ZZ Top sound, but I didn't measure those that I put inside.