Hey Guys,
What is the best way to test the function of an LFO without an oscilloscope?
Should I use the output to trigger a transistor and an LED?
I would welcome any suggestions.
Thanks!
Derek
You could do that. Alternatively, you could set it to the slowest speed, and park the probe of an analog voltmeter at its output. I stress analog because the needle yields a more coherent indicator of cyclical variation than a digital readout. The advantage of the analog meter over the transistor/LED combo is that you'll know what the output voltage is, approximately.
I once tuned a sine wave oscillator using the method Mark outlined (twas a diode shaping affair). When I finally got a scope I breadboarded the circuit to check it out 'for real' and it was more or less spot on - not bad for a log meter!
To get the LFO slow enough to take a reading I paralleled really large value caps with the one that sets the rate (not always possible to do, depends on the oscillator).