Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!irwin From: irwin@m.cs.uiuc.edu Newsgroups: sci.electronics Subject: Re: Crystal radios - wasn't it a 'galen Message-ID: <21000048@m.cs.uiuc.edu> Date: 1 Dec 89 01:40:54 GMT References: <5386@internal.Apple.COM> Lines: 31 Nf-ID: #R:internal.Apple.COM:5386:m.cs.uiuc.edu:21000048:000:1528 Nf-From: m.cs.uiuc.edu!irwin Nov 30 09:13:00 1989 /* Written 11:57 am Nov 29, 1989 by henry@utzoo.uucp in m.cs.uiuc.edu:sci.electronics */ In article <24473@cup.portal.com> ISW@cup.portal.com (Isaac S Wingfield) writes: >>...we concluded that germanium diode specs >>were all kind of loose, and it was possible to duplicate (or even better) >>all specs *except* FCD using silicon, and that's what nearly everybody >>was doing! The ITT devices came in at 0.3V, and everything was fine. >I was sort of curious about this, and ran some tests on the 1N34s I've >got in my parts box at home. They are from Rockwell, I think -- at least >the tiny symbol on the side looks like the Rockwell logo! I *think* these >are germanium; the current-vs-voltage curve does start to break at 0.3V. >What startled me a bit was how gradual the rise was after that; within >the limits of my simple measuring setup, it looked like a near-linear rise >at about 1mA/100mV, whereas the one for a 1N4148 is nearly vertical at >circa 0.6V. Is this normal for germanium, or have I got something funny >like silicon pretending to be germanium? -- >That's not a joke, that's | Henry Spencer at U of Toronto Zoology >NASA. -Nick Szabo | uunet!attcan!utzoo!henry henry@zoo.toronto.edu /* End of text from m.cs.uiuc.edu:sci.electronics */ Henry, your tests looks ok to me, the last time I checked, a 1N34 was germanium and a 1N4148 was silicon. I have used both types through the years in various projects. Al Irwin Univ of Illinois Dept of Comp Sci Urbana, IL irwin@m.cs.uiuc.edu Brought to you by Super Global Mega Corp .com