simon.plata Posted November 3, 2017 Share Posted November 3, 2017 Hi, I tried some simple composite video mods for my Atari 2600 with terrible results: Blurry image, ghosting, dark image, etc. Then I designed my own mod and it works good enough for me. I wanted to share it with all who want to give a try. First you need to remove some components from the board. I prefer to remove all unused components and store them. But if you are more conservative then remove the following components only Also, you need to remove or disconnect the "RF Modulator Module" and built the Video Amplifier. I designed two simple video amplifiers: The first is a simple one stage amplifier. This circuit Works good but due to the limited gain of only one amplification stage, there is some limitation in the brightness of the image. Most people will not notice it, but I wanted to ensure the best quality possible keeping it simple. The second is a two stage amplifier. This is still a very simple circuit with flat gain up to 4.2MHz (Composite video band width) which ensures brightness and color preservation with minimun distortion. Use the 5K trimmer to adjust the gain (brigthness) of the signal. Teorically you will have 0dB or unity gain with 1577Ohm. This is the Bode plot of my LTSpice simulation of the circuit This is the board with the circuit installed And finally this is the results: Video on a CRT TV Video on a LED TV 7 Quote Link to comment Share on other sites More sharing options...
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