This circuit was found in the December 1992 Radio Electronis magazine. R2 is an NTC, there is a MOV protector or NTC thermistor. The current depends on the thermistor used.
This traditional direct amplification MW radio configuration was obtained in an American...
This filter, which rejects frequencies around 1 kHz, was found in the August 1993 Electronics Now...
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...