[sdiy] Matching transistors

[Tim Daugard]

From: "Tom Adam" <tom.adam at telenet.be>

What's the deal about those matching transistors?
Why and where do they have to match . . .

Better answered by others.

 and how do I know I got matched ones?

I measure Hfe at skin temperature. When the Hfes shown on the meter
are the same, I consider them matched.

I hold the transistors between two fingers while measuring. When the
reading stops changing, I assume that the transistor has stabilized at
skin temp. I then write the reading down. I figure it's a closer match
than trying to do it with the transistors being surrounded by air
currents.

Tim Daugard
AG4GZ 30.4078N 86.6227W Alt: 12 feet above MSL
http://home.sprintmail.com/~daugard/synth.htm