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 converts a high impedance signal into low impedance. The circuit has unit gain and...
With this timer we can start between 30 seconds and one and a half seconds, time set in the pot....
We found this circuit in the December 1968 issue of Radio Electronics magazine. The circuit is...