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Simple Tv transmitter schematic
This is a small tv transmitter circuit wich trasmittes in VHF, negative sound modulation and PAL video modulation.
It is suitable in countries where the B and G system is used.
88 108 MHz FM transmitter BF982 BF199 BFR90
The most important part of this 88 108 transmitter is the Colpitts oscillator. C3,C4,C5,C6,CD1-CD2 ans L1
determine the transmission frequency. The RF Oscillator circuit has the BF982 MosFet transistor wich is the active part. The others 2 transistors separate the VCO from antenna.
The first stage BF199 amplifies the weak signal from the vco and functions in [...]
Spy Telephone Schematic
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 wich act as anntenna. There is no need for batteries because it got his voltage supply from the phone lines.
There is no need for antenna too, the phone wires [...]
