Color CRT Television
Color Picture tube consists of three electron
guns which stimulate the primary colors using control grids and shadow masks on
phosphor dots coated on the screen. There
are mainly three types of color picture tubes
1. Precision In Line Picture Tube |
2.Delta Gun Colour Picture Tube |
3.Trinitron Colour Picture Tube |
Color Television Receiver Circuitry
The only difference
between black and White Television set and colour Television set is the IF
circuit is the importance of bandwidth for colour receivers. Remember that video
frequencies around 3.58 MHz just show details in monochrome, but
these frequencies are essential for colour information. Without them, there is
no colour. This is why the fine tuning control on colour television sets
must be tuned exactly, or else the colour disappears, along with the higher
resolution.
The sound is usually
taken off before the video detector in colour sets, and a separate
converter is used for it, instead of taking it from the video detector. The
reason that this is done is to minimize a 920 KHz beat signal that can result
between the 3.58 MHz colour subcarrier and the sound carrier signal. This
signal would show up as interference in the television picture.
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