hello, i’m new to video diy and i was trying to make the rgb encoder on a veroboard. i skipped the sync generator and replaced it with a LMH1980 to provide for the blanking, hsync and vsync. (found this in another thread here) i have 2 monitors and on my mini aliexpres car screen i get a lot of flickering and sometimes and image and on the other i do get a better result but very glitchy. it’s kind of cool somethimes, but not workable. the hsync and vsync of the LMH1980 seem to work because i get stable lines from and oscillator.
these are some questions that came up:
- is it possible to skip the sync generator and use a LMH1980 to extract hsync and vsync from a video signal and use that to sync the ad724 ?
- can the burst of the LMH1980 be used as a blanking signal for the cd4063 ?
- i’m confused about the 2 crystals in the schematic. i read in the ad724 datasheet that a logical high in the stnd input selects ntsc and a 3.579 545 mhz crystal in the fin input. so in the schematic the 5v goes through a 10k to the crystal. shouldn’t the crystal be grounded for it to be selected ?
some pointers or insight are very much appreciated.
thanks for reading,
lieven