Two-Tone Buzzer

No, this Project doesn't have two different colors of paint! It's an electronic buzzer whose tone you can change at a flip of the switch.

As you wire this Project, set the Select Switch to A. Press the Key, and you'll hear a tone from the Speaker.

Now set the Select Switch to B—what does the tone sound like now?

Look at the schematic— can you see why this happens? (Don't peek at the answer before you figure it out!)

So what effect do you think increasing the resistance in the emitter-to-base circuit has on an oscillator circuit like this? (Be sure to keep a record of your answer.)