This circuit was found in a 90s Wels' Think Tank. The frequency depends on C2 and R3. The handset or speaker must be at least 80-ohm. Observe the low supply voltage.
In the figure we have the typical circuit of a stereo decoder using the TBA450N integrated...
This test for electrolytic capacitors was found in the October 1960 Radio Electronics magazine. Note...
The selected circuit is from the Texas Instruments optoelectronics manual. With it you can receive...