Ummm...While working on my first fuzzface I think I killed my nice Germanium transistors from small bear. This is my first potentially costly mishap. I got a little overconfident and put them both in backwards...sux
:cry: whhhaaaaaaa!
...It was my first time to use a breadboard and I started working way too fast for someone of my modest ability level. Just to make sure that I am right I'd like to find some way to check them out. Is there an easy way to test them with a DMM that doesn't have the ability to measure hfe? I've built an audio probe and it sounds like lots of stuff is losing level after Q1. Is that the best test I can hope to do without buying a new DMM? I'm gonna doublecheck the debugging page and RG's faq at GEO but I think it's gonna be a total loss on the transistors unless there's something cool you can build with messed up ones.
As usual any help will be appreciated...
peace,
James
they probably aren't messed up.
you can do a quick check using the diode setting on your meter. check from e to b and from c to b and look for a voltage around .2 to .3 volts on your meter. if you don't see anything, reverse the leads. once you get a reading, keep the same color lead on "b".
if you manage to get a reading of .2 to .3 volts on both e to b and c to b, your transistor is probably ok. you can usually do this test even if the transistor is in-circuit, but disconnect the battery.
Ok...On the one I was using for Q1 I got .180 from c to b and .185 from e to b. This was originally in a bag that Smallbear had labelled as 97...But I bet I'm comparing apples to oranges. On Q2 I got .178 from c to b and .182 from e to b. Again this one was in a bag that read 152. It didn't quite come up to the .2 to .3 range so does this mean that it's likely I toasted them? Do you think there's any chance they'll still work right?
You know...I think I like just soldering the parts on a PCB or perf first using sockets and stuff...I work more carefully that way...
Thanx for the help so far!
From your post it sounds like they're probably ok.
Jered
dibs on "Killing Cool Transistors" as a band/album name...
Kerry M
Putting ebc instead of cbe won't hurt a transistor.
Other swaps might hurt, though.
Quote from: Paul Perry (Frostwave)Putting ebc instead of cbe won't hurt a transistor.
Other swaps might hurt, though.
Is that true in this case just because of the low voltages(9volts) or always true as far as you know, even with say 12 volts?
12 volts is still low voltage. your transistors sound fine. just put them back the right way and press on.
My breadboard is a really old one that I borrowed from a friend...I couldn't get the circuit to work in it and thought I had killed the transistors. So I just built the board with perf and used lots of sockets and headers and it worked on the first try. It sounds great! Thanx to everybody, especially Mr ZVEX for helping me to get over my chicken little freakout.
peace