High Speed vibration, can't find what's causing it.

I bought one of those 50-60 year old bubble balancer for the right price years ago. But to do my 14 inch slicks I bought a Harbor Freight balancer as I couldn’t do my slicks on my other one. If you pre level the balancer right it works great. I have to do that job when I’m fresh because by yourself it’s a little tricky.
I have a tire sponsor who is going to put them on his machine for me.