Im wondering if it would make sense to design a luma encoder DIY module.
The simple way is just to mult a signal to all three inputs of the C2, but my initial thought is that there might be a cheaper/smaller/simpler build possible? Perhaps a dual channel luma encoder would be even more cool.
Would have only one Jack input per channel and therefore only need for one buffered input per luma channel etc…
It of course halts on the assumption that the ICs ( AD724?) doing the actual video signal magic can be found in a single channel/luma version instead of the now used RGB color version.
With my limited knowledge, i searched the analog devices homepage, but it seems there ar only RGB and more advanced chips being produced by them. But perhaps there exist other suitable manufacturers or even older ICs still lying around that could be of use here…