Using the 2N2646 this circuit was found in a Radio Electronics magazine from July 1968. The transistors are from the time and the lamp can be replaced by a high-power LED in a current version.
This circuit operates with frequencies from 0.5 to 400 MHz. We find it in a 90’s NASA...
CMOS 4046 (PLL) is not very common. In this circuit it generates short pulses to excite a high...
This circuit to produce clock pulses is manually driven. The circuit is TTL and must be powered by 5...