The attached pdf file provides a circuit diagram, list of components, pictures and basic instructions for constructing a simple circuit that will simulate the sound of the small diesel engine that powers mechanical reefers.
Groovy! My pop has everything on that list at his workbench, except for the speakers. Are they a "standard" Radio Shack item?
John, I updated the pdf file to include more info on the audio transducer for this circuit, including where to find it.
