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Old 09-02-2016, 02:59 PM
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old_tv_nut old_tv_nut is offline
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Join Date: Jul 2004
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I think you are more likely to find CRT drivers with feedback in computer monitor designs. Usual TV drivers were class A resistive loads, with large power dissipation. Like tube video outputs, they were run with the maximum gain possible to reduce the need for multiple earlier stages. Transistor sets, especially once video ICs were introduced, still commonly used class A outputs, only now there were three for R,G, and B. Push-pull outputs were also developed ( I remember them in European sets)- much less power dissipation, and less hefty transistors could be used, but the CRT arc protection had to be better to avoid frying the smaller die. The class A outputs would get quite non-linear at high frequencies and large signals due to the capacitive loading of the CRT, but it didn't make much difference for a 3 or 4 MHz bandwidth video signal - just put in emitter peaking capacitance to get enough amplitude and don't worry about the shape of a 4 MHz sine wave. Computer monitors needed more bandwidth, and hence more complex design; also compromises like even more output current and dissipation, less output swing, etc., etc.

The above is my partial knowledge and memory of the status of things in the mid 80s, so I am sure there is more to learn.
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