Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz operating on the third harmonic. The transistor admits equivalent.
This filter with the 741 op amp was found in the February 1995 Electronics Now magazine. The power...
Suggested by an old American documentation the circuit below keeps a battery charged and at the...
Found in documentation from the 90s, this circuit was used in communications receivers of the...