I did this 20 years ago when my wife insisted I get PBS (channel 28) which wouldn't come in on the VHF/UHF antenna. I added the UHF antenna 4' below the VHF/UHF antenna. Problem was solved. I now have a UHF/VHF antenna that gets digital but not 100% reliably. I plan to lower the VHF/UHF antenna 4' down the mast and add a UHF antenna on top (probably a CM4248). Twenty years ago VHF was my priority, now UHF is my priority.