Not a problem. If you are trying to make the transistor impedance
converter, and you have a Rat Shack 2N2222 or PN2222 or some other garden
variety NPN transistor ... then ...

Look at the "front" of the transistor. That's the "flat" side. Hold the
transistor with the flat side towards you and the wire leads down.

From the left to right, the leads are "emitter", "base", and "collector".
Don't worry about what the words mean right now.

You also have several inputs to this little amplifier. One is the +12
battery voltage. One is airframe ground. One is the Alpine audio output.
(The Alpine needs a common ground to airframe.)

The collector of the transistor goes directly to +12 battery supply (through
a LITTLE TINY fuse).

The emitter goes to ground through a 470 ohm resistor.

There is a 47K resistor going from the collector to base. There is a 47K
resistor going from base to ground.

There is a 100 nF capacitor (0.1 uF) from the Alpine audio output to the
base of the transistor.

There is a 10 uF capacitor from the emitter of the transistor to the input
of the audio panel. This will undoubtedly be an electrolytic, so the (+)
lead of the capacitor is to the emitter of the transistor and the (-) lead
is to the audio panel.

Did that help?


Jim






Yes, for someone who knows what it's talking about - I don't even know
where to begin. It appears they come up with numbers from who knows where
and I don't think they start with the impedance and go from there. That's
my problem - I don't want to spend another day staring at those equations
only to get frustrated if someone could just tell me where to begin!

Brian