I have been given a quantity of TO-92 transistors with the National Semiconductor brand on them. However, I cannot identify them. When I asked National, they told me they sold their discrete line to Fairchild in 1997. The Fairchild Web site isn't very tech-question friendly, and singularly bereft of eddresses, so I'm going to ask here in a better hope of getting an answer.

 

There are two types; all have colour codes on the back:

 

427 A05 yellow-red-purple

333 A05 silver-silver-silver

 

Anyone have any inkling? Only three colour bands doesn't sound particularly useful, but..

 

Thanks!

I don't know what the colours represent in Ohms, but could you not put a small votage through one of them with an ammeter linked to it and work them out?

I`v just had a look through my semiconductor index and there`s nothing by Fairchild in a To-92 case that matches that description.

I will say however that most all of the color coded T0-92 devices I`v come across have been FETs (P and N channel).

 

it would be a good idea to buy or borrow a multimeter with a transistor test socket on it, at least you`ll be able to find out what sex it is, it`s gain and EBC layout.