This type of answering machine was common at the time this circuit was published. Using two tape recorders, it was published in the June 1986 issue of Radio Electronics magazine.
This circuit was found in the February 1981 issue of Radio Electronics magazine. The circuit uses...
Found in American documentation from the 90's, this circuit oscillates up to 150 MHz. The...
This circuit can work with power voltages from 6 to 35 V, being suggested by the Motorola Linear...