Doesn’t support system NTSC-M/PAL-M/PAL-N (4.5 MHz sound carrier). It only supports 6.5 MHz sound carrier system PAL-D/K or SECAM-D/K format. Need to choose or ask if there’s any system M or B/G sound frequency system. Not compatible with any NTSC only tuner TV sets. Colored NTSC picture but no sound.
video output works. Audio does not. At least that's the case for my PAL televisions. I live in Europe, all my CRT TVs are PAL and they there is no sound. Just static noise sound. This was also the case for another model RCA AV to RF converter I bought in the past. I guess there is nothing to do about it.