Telephone History, How telephone works, Identifying Electronic Components, Telephone Privacy Guard, Modem Protector, Phone recorder switch projects, The frustrator, Hold circuits and projects, Telephone Ringer Projects, Phone line Status Circuits and projects, telephone Ringer Projects, Phone line status Circuits and Projects, telephone and Phone Line testers, FM telephone transmitter, telephone projects, Talking / Musical telephone Ringer, telephone Tollsaver, Infinity Bug/ Transmitter Projects.....