Another RV Directv question

My grandpa just got a new travel trailer and we are looking for an automatic antenna. Looking at the King KOP4800 pro, but had a question before we buy. The King product specs say that it only does standard definition, which is fine, but we're wondering if the HD channels still come through just in SD? Or will those channels not come through at all? His receiver is an H24-100. Thanks in advance.