ok i ordered trannines from small bear...and the gains are marked on the bag...but i cant find any info on what gain to use for each stage...
help???
lowest gain for first stage, highest for last.
also what is the pin out on these trannies????
what type are they?
the ones I got from smallbear were unmarked. They have a little "nose" where the emitter is. When the emitter is to the left, it's E-B-C.
But please list the type. What is printed on them?
2n404a
2n1305
:shock: no idea what those are.
Email him! Or do a google search for their spec sheets (if any).
You should be able to find the base emitter diode using your Dmm.
The other one would be the collector...
petemoore, I just tested that... can you explain how exactly to do that?
of course if you have a dmm which measures hfE, just pop them in there and turn them around until you get something reasonable. you should know if they're NPN or PNP though. As they are for a tonebender, I'd say PNP. But 2nxxxx is unlike any Germanium I've ever seen (haven't seen all of them though) :?
IIRC I put the DMM in Doide mode,
Took a regular diode to see what it looks like on the meter, also inverted it and looked. One way Beeps the other way gives a [foreward voltage reading?] something like .7v for Si...
Been a while...hope I'm not running you up a tree here...
Anyway, I figured out at least the the base is middle on the transistors I was testing, so I went from middle to outside, the outside to middle on the DMM ...
So for each way from the middle I took two checks..first 'one' way, then 'other' with reversed polarity of the DMM leads.
I found that the DMM acted just like when I'd tested the diode both ways, and I believed I'd found the Emitter diode and base.
Another way I do it is with the DMM's Hfe checker. You may have to try both 'sides if you know not PNP or NPN.
You should get some kind of 'normal' hfe reading..[after you stick em in there everywhich way...] like if your Ge transistor's supposedly rated at between 100 and 150 Hfe and it reads 148 or even 180 [they leak sometimes] you probably have the correct pinout marked on the DMM.
I think I had either way working at one time or another. HTH
Ah, I see. Exactly what I did.. the problem is, I get a voltage reading on both sides! I mean, a tranny is practically made up of two diodes. Using that method, how do you know which diode is which?
The only way to determine it would be if the base/emitter diode had a lower/higher forward voltage than the base/collector one. All the time I mean.
well. The method with the hfE checker works, though. I often use that.