Help Video scope

Hi everyone

Help please :stuck_out_tongue_winking_eye::upside_down_face::melting_face:
I have a b&w video x op a old tv with Ariel cable only

I bought a rf converter

Put it all together and all I get is a faint hint at the scope imagoes like in the demo video

The image is horizontal not vertical and strobes

Do I need an another tv or maybe a projector ? I really wanted to use a old tv

I’ve been trying to tune in the the tv and scope but no improvement

It’s bugging me

How do I get it to work ?