Black white video scope help can’t get it working

Hi everyone

I have a black and white video scope
And a old tv with Ariel only
I’ve bought a converter for it
And connected everything together
I get something but it’s a horizontal image not vertical ?
And I only get a small
Part of the image and it’s stoning all the time ?
I have played with tuning the tv for ages no improvement

Looks nothing like the demo video
I’m in the uk do I need to buy anything else
It’s so fustrating I thought it would be easy to set up
Any help on this would be fantastic