I don't know the difference between a pnp and an npn, but I had a transistor. All I knew was the middle terminal acted like a valve for current to pass between the outer terminals. So how did I find out? I used a pot to find breakdown, replaced it with an equivalent resistor, and went from there. All I know from there is when the base was grounded, it opened the valve, and I had my circuit.
Later I was working with a reed relay. Apparently the coil was polarity sensitive, so I figured that one out and I had my circuit. That doesn't count all the time I spent trying to use a transistor. This time it failed. The voltage on the radio speaker wasn't enough.
So now I have two clocks, one with a fire alarm bell and the other with a fire alarm buzzer pending shipment. When it gets here I can just conveniently plug it in to the extension cord female dangling off the back of the clock.
If there's a mistake that can be made, I will routinely make it.
Mistake Crusader Jon from Ohio