DVD players make for excellent sources of TV signals for vintage TV sets. The video signal has precise timing and the proper ratios of sync signals, unlike VCR tapes. Also, when using with B&W sets, use the "Y" or "luma" output to feed the TV modulator. The color information is separately stored on the DVD disk, and is only merged with the luma at the "composite" video output jack.
Here I installed a TV modulator inside a DVD player .