Hi Steve,
You were right! The problema was in my oscilloscope probe. Anyway, I have connected the encoder with a CLC021 serializer and the image is bad. The problema is not in the CLC021 ic because I have generated several test patterns from it and them work properly. The 8 bits from the encoder go to the 8 MSB of the serializer.
I have switched the register 0x03 in the TVP5150AM1 to change from high impedance to signal the 8-bit ITU-R 601 signals. Should I change other registers?
Thanks and regards,
Félix.