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.
The input of this circuit remains in a high impedance state when the power of the LT6100 is cut...
This low voltage circuit was found in the November 1960 Radio Electronics magazine announcing new...
This high impedance driver was found in a 1980s documentation. The integrated circuit is a type of...