The block encoder of the PAL encoder is shown in the figure, it uses gamma corrected RGB signals from the camera tube as input and produces the overall color video signal at its output.
- With the help of metrics, the Y signal and the weighted color difference signal are produced by the R, G and B signals. The bandwidth of the B - Y and R - Y video signals is limited to 1.3 MHz using a low - pass - filter. During this process, the delay is created in this signal compared to the Y signal and to end this delay, the delay line is inserted along with the Y signal.
- The weighted color difference video signal is fed from the filter to the balance modulator. The sinusodial subcarrier is fed directly onto the U modulator and fed to the v modulator by providing a phase shift of 90 °.
- A quadrature quadrature) amplitude modulated (Q.A.M.) chrominance signal is generated by connecting a double side band spread carrier (DSB - SC) received from the modulator
Link ⤵️
BLOCK DIAGRAM
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| PAL CODER |
It is then passed through a filter that removes the harmonics of the subcarrier's frequency and holds the upper (lower) and lower (lower) sidebands to a value. The output of the filter is fed into the adder. Here it combines with luminance and synchronous signals to form a composite video signal. The bandwidth and location of the composite color signal (u and v) along with the Y signal are shown in the figure. In this, the color brust signals are also fed with the help of the adder. In this way, composite color signals are received at the main transmitter.
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