Spy Telephone Circuit

This FM spy telephone circuit is mounted serrial with the phone line. When is signal on the wires this transmitter will radiate airwaves thru the wires wic..

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Watson   Oct 10, 2017

Thais circuit does not have a Zener diode to protect it against excessive voltage. The 6 to 9 volt Zener should be across the supply to limit the voltage. This circuit must be connected in series, where the phone line enters the house from the street. Thanks.

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