I have a little square wave generator that uses 2 of the inverters on a 40106 (very simple circuit with a capacitor, a resistance and a potentiometer) and using two 100k resistance to mix the two signals
But when i try to tune both waves at the same frequency they end up cancelling each other, what can i do to stop that ?
Are they inverted from each other, try running one of them through a spare inverter and then mixing them together, only thing I can think of is phase cancellation. I remember mixing my who rig back in to the mixer at some point from the monitoring and getting no sound at all. It was 180 deg out of phase.
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It’s a characteristic of the 40106 that oscillators made from one chip tend to cross talk with each other. In your case, it may be that the result is they’ve become locked at 180 degree phase, in other words, one is the inverse of the other, so when summed they cancel.
There are 6 inverters in the chip. Have you tried using different pairs of inverters? Perhaps some other pair would have less cross talk, or might lock at 0 degrees phase.
If that doesn’t work, using one inverter from each of two chips might.
Or convincing yourself that having two oscillators producing the same frequency with the same waveform isn’t that useful anyway…
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I tried to use the two farthest inverters on the chip and the waves are now in phase ! Sadly there is still a lot of annoying cross talk but it’s not cutting the waves anymore
Thank you very much for your answer !
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