Need some transistor testing mansplaining

[swelchy]

so I watched a recent video about curve tracing germanium transistors to get a better idea of a closer HFE and leakage than just throwing them in the dca75 and hitting the go button.. which is what i've been doing and have gotten lucky most of my builds.... I attached two pics of the same transistor measured on the dca75.. one is just the simple identify test and the second is a trace curve setup in the parameters as the diy guitar pedals guy explain on his video.. so if this curve trace simulates the small bear test method would i assume that this transistor is 100 HFE with 1.124 Ma leakage? isnt that over a thousand microamps and considered a reaaaaaly leaky transistor?

 

[steviejr92]

Yes that is one leaky transistor! I think anything over 300ua is considered really leaky!

 

[swelchy]

can anyone confirm this is a good way to test? and that the parameters i have set up look correct?

 

[steviejr92]

Ive done this exact test before and know the video you speak of. It looks like you have the correct parameters that ive used. Im sure someone more experienced will know more.

 

[swelchy]

the curve trace gives it a much different hfe and leakage result

 

[swelchy]

trying to record my stash so i have some numbers on them... going to send someone on here a set for an mk1.. so i'm trying to find him an ideal set... The last coupple tone benders i did them with the breadboard test to get the numbers and that was a pita

 

[steviejr92]

Yup ive stopped using it because it kept reading all of my transistors as really really leaky but when i would put it in the CCT it would be well below what the curve tracing on the DCA was reading. I started only using the curve tracing on the DCA to find accurate hfes...

Im sure theres a better method to measure leakage on there.

 

[SillyOctpuss]

the curve trace gives it a much different hfe and leakage result

The curve trace will be giving you leakage and hfe at a range of +/-12mA. When you just use the simple test it's just one point on your curve trace at 5mA. They're both accurate to the test current that was used.