Building RG's tranny tester to test mainly Si transistors. Is this a good idea?

Started by cthulhudarren, August 04, 2011, 09:40:52 AM

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cthulhudarren

I don't have a DMM transistor checker, and am interested in making RG's tester. But I am mainly interested in testing Si transistors like BC109s but may occasionally test a Ge. I think the tester should work for Si transistors. I have searched the archives here and seen some threads about the tester.

I want to test the transistors for using in fuzz boxes and the input fuzz circuits of early SS Vox amps. Is the base current in the stock RG tester okay for this task? Right now I think the answer is yes though I'm not sure.

I was thinking of regulating as close as possible the 9.0v with a L7809Cv 1A regulator.

Thanks in advance,

R.G.

It will do it fine, although silicon is generally completely free of the leakage that makes testing germanium that way necessary. If you do it that way, you may as well skip the leakage "gain" test. With silicon, it will be uniformly so near zero that the test isn't needed.

And it's just as well to test silicons in a meter with a gain test. This circuit doesn't ensure greater accuracy. It just does a consistent test of leakage and real gain so you can separate them out.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

cthulhudarren

Quote from: R.G. on August 04, 2011, 11:03:22 AM
It will do it fine, although silicon is generally completely free of the leakage that makes testing germanium that way necessary. If you do it that way, you may as well skip the leakage "gain" test. With silicon, it will be uniformly so near zero that the test isn't needed.

And it's just as well to test silicons in a meter with a gain test. This circuit doesn't ensure greater accuracy. It just does a consistent test of leakage and real gain so you can separate them out.

Thanks RG. BTW, I sent you an email a while back with detailed shots of my Defiant amp. Did you get that?