Transistor hunt.....

[182201]

I have access to 200 boards from Hewlett Packard computer audio cards. Each board has 8-13 transistors.

What numbers or models should I look for?? I have one here and it has:

(texas state) 2N1304-7005B AND 2N388A-7010
ALSO 1853-0001-7016A

1850 0062-274

M 1850-0040-013

NPC 185001.01

Any of those for anything? I have them for free.

[petemoore]

Type in NTE, in the adress bar, and when you get to the transistor and IC cross reference guide page, save it to favorites...punch your numbers in the bottom window of the CR guide...see what NTE says ab out them.
 Then, if you're DMM has a Hfe checker...build a pin extension socket...[three pin socket with wires from the bottom of a small perf piece that will poke deep into the DMM's Hfe checker socket....then you can easily test your 'shortleg' Q's...
 stick them in the Hfe checkers pins every which way till you see an Hfe reading that looks reasonable...then read whether thats PNP or NPN and what the pinout is....I don't know that this does or doesn't work with FET's...if the source or emitter is in the middle it wont...unless you 'twist' two legs...

[Paul Perry (Frostwave)]

2N388A in a computer audio card??
acc to my databook here, 2N388A is a NPN Ge!!
just google it & you get refs to various fuzz face derivatives.
Oh and the 2N1304 is PNP Ge, all I can imagine is that they are part of a low voltage complementary pair output??? good score, anyway!

[182201]

Type in NTE, in the adress bar, and when you get to the transistor and IC cross reference guide page, save it to favorites...punch your numbers in the bottom window of the CR guide...see what NTE says ab out them.
 Then, if you're DMM has a Hfe checker...build a pin extension socket...[three pin socket with wires from the bottom of a small perf piece that will poke deep into the DMM's Hfe checker socket....then you can easily test your 'shortleg' Q's...
 stick them in the Hfe checkers pins every which way till you see an Hfe reading that looks reasonable...then read whether thats PNP or NPN and what the pinout is....I don't know that this does or doesn't work with FET's...if the source or emitter is in the middle it wont...unless you 'twist' two legs...

HUH....

This is my first foray into transistors...which ones of these are useful???

I will have to desolder them from the boards but could have hundreds if I want them.

What are the most wanted ones to search for??
This place is huge and has thousands and thousands of boards.

[phillip]

The 2N388 makes an excellent fuzz transistor for classic fuzzes, like Fuzz Face and ToneBender MKII, that you want to make into a NPN Germanium.  I've used them extensively in such circuits.

The 2N1304 is also an excellent fuzz transistor, but it's actually a NPN Germanium like the 2N388.  I had some that I made a NPN Germanium Fuzz Face out of, but it's a very aggressive sounding transistor...I much prefer the sound of the 2N388.

Phillip

[Mark Hammer]

Get yourself a pack of solder wick and get to work, fella.  A simple and cheap way to assure that you don't damage too many by heat is to take a piece of paper towel or toilet paper, wet it with cold water and squeeze it out, then clip it to the metal cover of the transistor with an alligator clip.  The water will not damage the transistor.

A stockpile of 2N388A's will make you a heap of friends in a hurry. :wink:

[182201]

A stockpile of 2N388A's will make you a heap of friends in a hurry. :wink:

Will do.  I 'll get some boards and start this over the weekend. How can I measure them to see if they are good. OH yea these boards are from the 70's and are NEW/ some never opened!
(I will pull all the 2n388a's first)also on these boards is  a 2n708-012M

any other magic numbers to look for?

[Paul Perry (Frostwave)]

(I will pull all the 2n388a's first)also on these boards is  a 2n708-012M

No, pull the other stuff out first, for practice :wink:
One method that worked for me, was to attach a spring clamp (actually pliers with a rubber band around them) to the transistor I wanted, so it dangled under the board, then I melt the solder on all 3 legs & the weight pulls the transistor out, it & the pliers drop to the table.
But with that many, you will soon work out the best way!
The 2N708 is a npn silicon.