This looks like an analogue RGB to video converter.
But what you need is a RGBI (red, green, blue, intensity), (also called digital RGB or RGB TTL) converter to video.
As mentioned, if your TV can accept analogue RGB signals then you just need a converter for analogue to digital RGB, which might be cheaper or easier to make one yourself.
I found schematics and it isn't that difficult!
You just need 6 resistors and 3 diodes.
Here is a German site which explains how to do it (even when you cannot read German you can see the schematics):
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