Has anybody ever found an adapter that fits the odd Jaguar antenna connection that seems to be the same size as a coax cable?

I replaced my aerial antenna with Sams instructions but reception is poor in my area. "https://www.youtube.com/watch?v=vbrHsQ4ORqU"

I think I'm going to replace that setup with a Jensen Amplified Antenna and I would like to get the correct adapter...