Dvd to multple tv's

I have a dvd to link up to multiple tv’s. Have an rf modulator, chan 21-69 preset to chan 40.

Problem is rf mod only has red and white input sockets.My question is do i plug white into digital socket on dvd or yellow(yes sounds stupid i know) socket? Now i believed when all these plugs and sockets were in place, all you had to do was tune tv in. What is stumping me is this, i have modulator on chan 40, so does that mean i have to turn tv to channel 40 and tune in? I have heard channel 2 and 3 is the chan to tune to, does that mean i have to change channel on modulator ? Hope you understand what i am trying to say. And no, i cant use scarts, dont know why, just been told it has to be co-axial.

Thanks in advance.

Sorted the problem. The printing on the rf modulator was wrong, or the plugs inside were back to front. Swapped the cables round, white to audio and red to video out. Worked a treat.