Question How to hook up a PS4 to an old tv that only has a coaxial hook up?

[Paigenicolemcg]

hey guys! So my 12 year old is super into vintage electronics. His dad recently passed away and he had an old box tv in his room at his dads House that he would play his wii and Nintendo on. When his dad died, his beloved box tv got thrown out. So i searched everywhere and finally found him an old magnavox from the 80s. He really wants to be able to play his dads PS4 console on this old tv and i can't seem to figure it out. Nothing online has been helpful so far. I bought an RF modulator and an HDMI to AV converter. I have everything hooked up correctly however the tv just displays these thick rainbow lines and the words "no signal" on it no matter what I try. Can anyone help me, please? Do i have the wrong converter? I really want to figure this out for my son. Any advice would be so appreciated!