Transistor or diode??

[Johnnyorange500]

Hi,
I got this in a job lot of germanium transistors.. Was just wanted to identify it? Is it a transistors that’s damaged and is reading as a diode? or is it really a germanium diode? Heres the reading I get for it.. is it worth keeping?

Johnny

 

[jwin615]

Gonna say diode here. They're matched.
Or maybe a Darlington pair that confuses the tester?

 

[Feral Feline]

Diode.

I've seen similar before and there are three-legged Schottky diodes and then Lasers of course.


Schottky

 

[spi]

I say transistor. I had one of those testers and it couldn't identify jack. Try testing with RG Keen's method.

 

[Johnnyorange500]

I say transistor. I had one of those testers and it couldn't identify jack. Try testing with RG Keen's method.

Yeah, that’s what made me wonder. I’ve tested a few transistors and on occasion using the TC1 the results have come back with a diode and even resistors..?? But after multiple tries it normally gives me the right result, but not with this bad boy tho??! So who knows.. there’s defo some faint markings on the can but I’m not able to read it.

 

[Kroars]

I use the same tester for quick results, because they work pretty darn well, for the price. If I ever question the results, I’ll bring out the DCAPro. I’ll say sometimes it will have a glitch and I’ve had the same thing happen on a transistor that read as a transistor in the DCA, but diode in the TC-1. I typically use those TC-1’s to check resistor/capacitor tolerances prior to installation, cause they’re so quick and easy to use.

I will say, out of thousands and thousands of resistors tested, I’ve never had one that was out of spec. I still test every one though, cause I’m a bit nutty….

 

[Johnnyorange500]

I use the same tester for quick results, because they work pretty darn well, for the price. If I ever question the results, I’ll bring out the DCAPro. I’ll say sometimes it will have a glitch and I’ve had the same thing happen on a transistor that read as a transistor in the DCA, but diode in the TC-1. I typically use those TC-1’s to check resistor/capacitor tolerances prior to installation, cause they’re so quick and easy to use.

I will say, out of thousands and thousands of resistors tested, I’ve never had one that was out of spec. I still test every one though, cause I’m a bit nutty….

Yeah, I’m so tempted to buy the DCAPro. But that price tag puts me off every time. £160 call me tight!! But.. maybe one day.

 

[iamjackslackof]

Yeah, I’m so tempted to buy the DCAPro. But that price tag puts me off every time. £160 call me tight!! But.. maybe one day.

Calling @MichaelW . You are required to pass on the DCA bullying encouragement

 

[derevaun]

Near-faulty-to-fully-borked transistors will do that. Interesting Vfs though? Maybe try warming it up with body heat and see if it reads as transistor--it would at least clue as to which lead is what. In any case, it probably belongs in the overflowing bin of "these dead transistors will work great as diodes."

 

[Johnnyorange500]

Near-faulty-to-fully-borked transistors will do that. Interesting Vfs though? Maybe try warming it up with body heat and see if it reads as transistor--it would at least clue as to which lead is what. In any case, it probably belongs in the overflowing bin of "these dead transistors will work great as diodes."

Tried moving it about and warming it up. And got this reading? Think it’s probably worth tossing it in the bin… weird little bugger!

 

[derevaun]

The TC-1 should have a built in google search feature

 

[Johnnyorange500]

The TC-1 should have a built in google search feature

Ha! True.. I’m on it. Not sure it’s was worth all the hassle tho? What a bloody rollacoster! Does this mean it’s a closed case and I’m able to sleep tonight?!

 

[spi]

You should just stick it in a fuzz face and see if it fuzzes.

 

[Feral Feline]

If it is indeed a transistor, at least you can still use it as a diode.



I don't know if a borked transistor will still work as a diode, but I know a good transistor can be used as a diode.

 

[PedalBuilder]

Dead transistors or transistors with an hFE of less than 4 also read as diodes or common cathode diode networks on my DCA55. In my experience they work well as hard clipping diodes, but I've never tried them in a feedback loop.