Doug Petrie appeared in a web-based film in 2008.
An infinity transmitter -LRB- also known as a harmonica bug -RRB- is a surveillance device used to covertly monitor conversation in a room through a telephone line .. harmonica. harmonica. Its name derives from the fact that , by using a telephone line as a transmitter , it can work at an infinite distance , unlike other bugging devices that have only a finite signal range .. The alternative name ` harmonica bug ' refers to the fact that such devices were originally activated using the tone produced by a harmonica .. harmonica. harmonica. Design of infinity transmitters has varied , according to developments in telephone systems .. In some instances , the bug is activated after the target answers and hangs up their phone .. In countries where there is a delay between connection and the first ring , the bug can be activated before the target phone rings , so that the infinity transmitter essentially ` answers ' the call .. In more advanced systems , the transmitter can be placed in a parallel telephone line to prevent the victim 's phone line remaining engaged .. As modern telephone lines no longer establish a voice path until the call is answered a variant of this now exists that uses CND , or caller ID .. Usually an unusual sequence of non printing characters is used and thus will not show up on a display device .. Sometimes the caller ID device itself has the bug but it can be nearly anywhere .. In much the same manner a cellphone can be configured for silence on ring and auto answer and hidden , frequently placed inside something that has power available to maintain the battery .. This allows the infinity transmitter to be hidden inside an automobile or other location where a land line is not an option .