Audio amplifier motor-boating sound.
Adding a Pre-Amp in front of the LM386 creating a Motor-boating sound when I increased the audio volume .
Obvious wasn't due to interaction between audio amplifier circuit and radio frequency circuit .
A good shielding and power supply decoupling may solve this .
See 30 sec motorboating video clip .
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Adding a Pre-Amp in front of the LM386 creating a Motor-boating sound when I increased the audio volume .
Obvious wasn't due to interaction between audio amplifier circuit and radio frequency circuit .
A good shielding and power supply decoupling may solve this .
See 30 sec motorboating video clip .