This crystal or galena radio uses a germanium diode. C1 is an old radio variable and L1 has 100 turns of 26 or 28 wire in a 1 inch PVC pipe. The antenna must be a long wire.
Figure bellow shows how the flip-flops of a 4027 can be connected to perform a divide-by-5 counter [odd...
The basis of this 90s circuit is a CA3130 operational amplifier. The circuit does not need a...
With the indicated components, this circuit oscillates at 1232 Hz. Consider the tolerance of the...