Electronic Circuits and Diagram-Electronics Projects and Design

TV transmitter circuit. A very simple and high quality TV transmitter circuit based on IC MC374 is shown in this article.MC1374 is an integrated TV modulator circuit that can be used in various TV transmitter applications. The MC1374 includes all necessary circuitries required for a TV modulator such as sound carrier oscillator, FM audio modulator, dual input RF modulator etc. The IC packed with a lot of great features like wide dynamic range, single supply operation, low distortion, variable gain radio frequency modulator section, minimum intermodulation distortion, + or – Sync etc. The IC requires few external components and can…

Description. The circuit shown here is of a TV antenna booster based on the transistor BF180. The circuit operates in the UHF band and has a gain of 15dB. Capacitors C2,C3 C4 ,C5 and inductors L3, L4 forms a UHF band pass filter. The input signal is fed to the emitter of Q1 through this filter. Resistor R2 and R3 biases the transistor Q1 which is wired in the common base configuration. Circuit diagram. Notes. Assemble the circuit on a good quality PCB. For better performance, enclose the circuit in a metal box. The circuit can be powered from 12V…

Description. Here is the circuit diagram of simple but highly effective TV remote jammer circuit. Most of the TV remotes have 38KHz operating frequency. A flood of IR beams in the same frequency can easily confuse the TV receiver and this is the operating principle of our jammer. The circuit is nothing but an astable multivibrator based on NE555 IC. The output of NE555 is amplified using a PNP transistor SK100 to drive the IR LEDs. Not only TV remotes, but any IR remotes operating in the 38KHz frequency region can be also jammed by using this circuit. Circuit diagram….

Description. The TV transmitter circuit given here uses UK standard 1 FM modulation for sound and PAL for video modulation. The audio signal to be modulated is pre-amplified using the transistor Q1 and associated components. The transistor Q2 has two jobs: production of carrier frequency and modulation. The pre-amplified audio signal is fed to the base of transistor Q2 for modulation. Capacitor C5 and inductor L1 forms the tank circuit which is responsible for producing the carrier frequency. The video signal is fed to the emitter of transistor Q2 via POT R7 for modulation. The modulated composite signal (audio+video) is…