Demodulation video signal to pal
I saw schematics for "PAL TRANSMITTER" in the web, this is called modulation.
But how do I demodulate PAL signal? Any schematics, please?
Would it be possible to get circuit from old CRT TV receiver and just hook up the RF input and get PAL output from there?
A much better solution, is to get yourself a discarded VCR.
Those VCRs were discarded because most likely a mechanical component in the quite sophisticated tape handling mechanism has been damaged.
But the electronic circuitry is usually fine.
VCRs came with TV tuners and the PAL (or NTSC) demodulators, and had output connectors in the back, where the demodulated baseband video and audio would be available.
The good thing of a VCR versus a TV, there are no high voltages present.
PAL is a fairly complicated modulation scheme which involves quadrature modulators and gated sub-carrier pulses. Demodulation is even more complicated by the need to phase lock the sub-carrier oscillator and detect it's relative phase shift to know when to invert the color information. As Schmitt Trigger states, designing one yourself is very difficult but everything is already built for you in a salvaged VCR. Although a demodulator will also be present in a TV, I would advise against trying to salvage one because they often rely on signals from the timebase circuits which you probably don't want to reproduce.
Brian.
European IC manufacturers don't release PAL Demodulator anymore due to DVB-T broadcasting but some far-east sourced ICs can be found in the market.
Application is so simple.Differential IF output of a Analog Tuner is filtered through a SAW filter and applied to Video-Sound Demodulator Combo.The outputs of the IC are Baseband Video Signal (CVBS) and Audio.