Transistor pinouts

MikeH · October 19, 2006, 10:21:14 AM

I know that there's no convention on transistor pinouts overall, but can pinouts differ between companies for the same model? Like a J201 from manufacturer A is a DSG, but maybe the same model J201 from random company X is a DGS or something like that. I ask because sometimes it's hard to find data sheets for older components or ones made by random, obscure manufacturers, but data sheets from companies like Fairchild and Siliconix, etc. are very easy to come by.

In short, is the pinout for a J201, for example, the same from company to company?

R.G. · October 19, 2006, 10:38:36 AM

Get out your ohmmeter, and look for which pins match which diode conduction.

The gate of a JFET conducts one polarity to both drain and source, and not the other polarity. Any two pins which conduct both ways must be the drain and source.

And yes, manufacturers sometimes produce same part number, different pinout. I was bitterly disillusioned by this at one point.

MikeH · October 19, 2006, 10:41:53 AM

Grrrrrrrrrr.... when will they learn?

Mark Hammer · October 19, 2006, 01:30:42 PM

Just count your lucky stars that you didn't get interested in pedal building when a walk to the nearest electronics distributor could not be followed up by typing "J201 pdf Fairchild" into Google and getting an instant datasheet that told you which pin was which. In them days, you went home with the part, and generally had NO basis for finding out which pin was which unless you had the appropriate equipment, or the distributor had a databook on hand that they let you consult and which was up to date.

Jay Doyle · October 19, 2006, 01:54:19 PM

Quote from: Mark Hammer on October 19, 2006, 01:30:42 PMJust count your lucky stars that you didn't get interested in pedal building when a walk to the nearest electronics distributor

...was uphill, both ways, in the snow?

Sorry Mark, but it was begging for it...

oldschoolanalog · October 19, 2006, 02:12:32 PM

...In bare feet!
apologies...

Mark Hammer · October 19, 2006, 02:37:29 PM

It wasn't so much the driving snow in both directions, the walking uphill, OR the bare feet. Actually, it was the fact that when you go there, theywere closed for inventory.

R.G. · October 19, 2006, 02:49:17 PM

... and semiconductors hadn't been invented yet.

Nor tubes.

Mark Hammer · October 19, 2006, 03:03:49 PM

Quote from: R.G. on October 19, 2006, 02:49:17 PM
... and semiconductors hadn't been invented yet.

Yup. The difference between NPN and PNP was which direction the sticks was pointin when ya rubbed 'em together, and a "field effect transistor" was when ya rubbed them together...in the middle of a field. And we had to use potato batteries! Can you imagne trying to power a Deluxe Electric Mistress with 13 potato batteries in series!?!

I better quit now. I think we're scaring the children.

Seriously, though. The ease with which one is able to find out particulars of components from different manufacturers these days has made a world of difference in the ease with which us folk here can do the things we do. I have some older SAM's Book transistor replacement guides, and a tattered old HEP replacement guide, and as a teenager babysitting at the home of a family where the guy was an EE, I used to browse through his Lafayette and Allied catalogues. As much info as they had, it paled beside what you can find out about a component nowadays. So yeah, we ARE lucky.

R.G. · October 19, 2006, 03:06:03 PM

Quoteas a teenager babysitting at the home of a family where the guy was an EE, I used to browse through his Lafayette and Allied cataloguesmuch info as they

Kewl... EE porn!

Did he keep them in his bottom chest drawer?

But you're right, we're scaring them.

OK, I'll straighten up.

puretube · October 19, 2006, 03:09:52 PM

recently came across an interesting schemo
of a "quasi-complementary" AC-powered tubeamp...

Jay Doyle · October 19, 2006, 03:29:57 PM

I'll admit that my whole experience with buying parts has been through RS, Small Bear and a couple of orders through the big places. All nicely static bagged and stickered...

I went into a surplus place around here in St. Louis and was hit by the old library smell instantly. I walked through slack-jawed at the stuffed PCBs from God Knows What stacked upon one another, bins that were marked '10k pots' that had 100 or so parts in them, none of them matching, and a literal WALL of boxes the size of banker boxes all absolutely filled to the brim with tubes, none packaged, most of the screenprint numbering rubbed off...

Kind of scary...

Though I did clean them out of their 3094s for 0.20 each...

MikeH · October 19, 2006, 03:38:33 PM

I've recently discovered how lucky I am living where I do. About 2 miles from me is a huge vintage and antique radio resoration supply store. All kinds of awesome and hard to come by parts at decent prices. If you're in the Detroit Region of Michigan, check out "Purchase Radio and Supply" in Ann Arbor.

Mark Hammer · October 19, 2006, 03:58:41 PM

Quote from: Jay Doyle on October 19, 2006, 03:29:57 PM
I'll admit that my whole experience with buying parts has been through RS, Small Bear and a couple of orders through the big places. All nicely static bagged and stickered...

I went into a surplus place around here in St. Louis and was hit by the old library smell instantly. I walked through slack-jawed at the stuffed PCBs from God Knows What stacked upon one another, bins that were marked '10k pots' that had 100 or so parts in them, none of them matching, and a literal WALL of boxes the size of banker boxes all absolutely filled to the brim with tubes, none packaged, most of the screenprint numbering rubbed off...

Kind of scary...

Though I did clean them out of their 3094s for 0.20 each...

Knowing how often there are undetected typos here, I have to ask: Is that 3094 or 3904? If the former, did you wanna come over to my house, and bring your parts bin?

Jay Doyle · October 19, 2006, 04:22:02 PM

Quote from: Mark Hammer on October 19, 2006, 03:58:41 PMKnowing how often there are undetected typos here, I have to ask: Is that 3094 or 3904? If the former, did you wanna come over to my house, and bring your parts bin?

It was the former. Thus, I bought them out. I couldn't believe it. I wasn't around when they first came out, but even at the height of their use they couldn't have been that cheap...

I'd love to come over and play, if, you know, you weren't in another country.

I've gotten really lucky on a couple of things, that being a big one, another was basically a huge ziplock bag (they type you put a blanket in) FULL of unmarked transistors that I got off ebay. I was the only bid and I think I picked it up for about $20. I got them in the mail, I paid more for postage than I did for the bag itself, they didn't look like much but I tested one, naww, that can't be right, then another and another... They were ALL germanium and all but a small percentage tested in a pretty decent gain range. Well at least the first 100 or so that I tested, after a while I thought, why bother? if it doesn't sound good grab another! There must be a couple thousand of them. Back before small bear (uphill both ways

) when there was more parts trading going on, I would normally just grab a handful and toss them in the envelope to whoever I was sending stuff to. I think they are 2N404 equiv. but I'm just guessing based on their shape. They sound good to me in the few fuzzes I've built.

Jay

puretube · October 19, 2006, 04:33:46 PM

CA3049
or
3094,

that is the question...

or:
2N3049

or
2N3094

or:
2n3904 ?

Jay Doyle · October 19, 2006, 05:39:34 PM

Quote from: puretube on October 19, 2006, 04:33:46 PM
CA3049
or
3094,

that is the question...

or:
2N3049

or
2N3094

or:
2n3904 ?

CA3094.

Boy, I'll be sure to be more specific next time.

Though that CA3049 looks rather useful to me, that would be PERFECT for building a discrete 3080. Anyone got any for some Ge transistors?

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Transistor pinouts

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