Electret microphone output

For my reproduction of the FredBox/SixBox I wanted to know how much voltage output to expect from an electret microphone. Actually my mind is already on a 6m QRP FM transmitter, but the output swing is good to be known.

The oscilloscope comes handy for this kind of measurements. A resistor, capacitor and a surplus electret microphone do the job. Then, speak into it. Oh, don't forget a power supply!

My daughter really enjoyed screaming into the microphone and observing changes on the o'scope screen. I couldn't have tested it without her.

At her loudest scream the microphone outputted 200mV peak. On the DSO she also learned which button would freeze the trace. It was a very instructive experiment for all of us!