Using the integrated circuit 723 we found this power supply in an article in the magazine Radio Electronics from August 1971. The transistor may be a BD136 equipped with a heat sink.
This circuit uses two Raytheon RC4558 operational amplifiers that are similar to the 741. The...
This small stereo amplifier for headphones was found in a documentation on integrated circuits from...
This is a MOSFET version of a grid dip meter for frequencies between 1.8 MHz and 150 MHz,...