Hmmm, thanks. It seems AHD 1 is 720p30 and AHD 2 is 1080p30, but basically just plain yellow RCA jack (just, well, overclocked accordingly). Usability as SDR depends on how well the genlock can be turned off, and how well the h/v blanking can be eliminated. One of them, the NVP6114, seems to have a COLOROFF_x register and a selectable color kill mode (no Y/C separation vs. after Y/C separation). The no-separation + color kill seems to be the closest to dumb ADC, if genlock can be eliminated. AGC seems to be somewhat optional.