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alternative to NPN 2N222 transistor

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bucky09

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alternative to 2n222??

hello everyone, please help!!
i need a NPN 2N222 transistor to finish my project. problem is this part is very old and hard to come by these days. there is a 2N2222A and a 2N2222 on the market but my problem is i dont know if either of these will do the same job? so my question is, what is the best alternative transistor to the old 2N222 as it needs to do exactly the same thing. thank you guys.
 

2N222 is an ancient germanium small signal transistor. You possibly find it in a museum or an antique shop.

For what purpose do you need it?
 

its for a small radio transmitter that needs to omit a clear, crisp signal of around 35khz within a 2 meter radius.
the power suply for this is a 9v battery.

Added after 2 hours 15 minutes:

i can get more information if need be. thanks for your time guys:cry:
 

Try OC72, more info at:
**broken link removed**

IanP
:D
 

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    bucky09

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thank you my friend. i will try this

Added after 5 hours 38 minutes:

if anyone agrees or disagrees with this, your thoughts will be most welcome??
 

I guess, a silicon transistor could be used as well for your application. By the way, 2N222 is PNP (as all germanium transistors), not NPN.

From the data I read, OC75 would be a better replacement than OC72.
 

    B

    bucky09

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if you're using is for the sole purpose of switching then i would recommend
2N3904 - NPN
2N3906 - PNP
both general purpose and easily available.

Best regards
Jamshid
 

FvM said:
By the way, 2N222 is PNP (as all germanium transistors), not NPN.
Click to expand...

I thought the AC127 was the NPN complement to the AC126 PNP?

Keith
 

oh dear, looks like ive opened a can of worms!!!
soldering irons at dawn. thank you all for your input. it is very much apreciated.
 

I thought the AC127 was the NPN complement to the AC126 PNP?
Click to expand...
Yes, I forgot about these transistors, used with small transformerless audio output stages. I should correct my statement to as most
germanium transistors I hope that my information about 2N222 is correct anyway.

Frank
 

I only remember them because I seemed to forever replacing them in faulty equipment for people!

Keith
 

keith1200rs said:
I only remember them because I seemed to forever replacing them in faulty equipment for people!

Keith
Click to expand...

did you replace them like for like keith or did you upgrade them??
 

This was in the early 1970s so I replaced them with the same parts. There wasn't any other option and I was a school kid with very little real knowledge so if there was another option I wouldn't have known how to do it anyway.

Keith
 

When replacing a small signal Ge with a Si transistor, you mainly have to care for necessary bias adjustment. Also the e.g. factor 100
higher bandwidth can bring up parasitic oscillations that have been unknown in the original circuit.

Unless intending to exactly restore an antique instrument, I opt for a Si replacement.
 

    B

    bucky09

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FvM said:
When replacing a small signal Ge with a Si transistor, you mainly have to care for necessary bias adjustment. Also the e.g. factor 100
higher bandwidth can bring up parasitic oscillations that have been unknown in the original circuit.

Unless intending to exactly restore an antique instrument, I opt for a Si replacement.
Click to expand...

what is an si replacement??
 

after much deliberation i will be off to the bootfair the weekend to take home some old radios to see if i can salvage an original replacment as i have no idea how to care for the nessessary bias adjustment. thank you all for your input
 

Also GE transistors operate at .3v instead of .5v for silicon.
OFFTOPIC: I wonder why back in the old days, it was mainly pnps but now mainly npns.
 

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