Use this simple circuit to listen to your programs as they save and load or to search for programs on tape without pulling the earphone cord and adjusting the volume control each time.
The circuit consists of one 3.5 mm (0.125 inch) phone plug wired to a 3.5 mm miniature phone jack with another 3.5 mm phone jack wired in parallel through a 1KΩ resistor. Build it into any type of holder (a Radio Shack project box is neat and inexpensive), although a metal housing helps avoid TV interference. Using a small coaxial cable (rather than separate conductors) for the wire to the cassette plug further avoids interference.
Once you build the device, plug the phone plug into the cassette earphone jack, an earphone into the jack with the resistor, and the ZX80 into the other jack. Now you can listen to your tapes through the earphone with the volume set to maximum, even if the ZX80 is listening too.
Paul Holzchuher called to tell a strange story. His ZX80 worked fine on the dining room table, but on an aluminum table it wouldn’t load prerecorded or newly recorded tapes. Raising it off the table with books was no help. A wooden table cured the problem. When you have trouble reloading programs, move your ZX80 to a non-conducting surface.