I recently completed this antenna made from parts and materials from home center and hardware store. From my rural area it picks up 48 channels/subchannels when aimed at transmitters 46 miles north on the far side of Washington, D.C., USA, and 30 channels/subchannels when aimed at transmitters 61 miles southwest on the far side of Richmond, VA. This model has high gain for UHF and VHF-high channels while not being very large, weighs 7.5 pounds. My Instructables series about constructing a simpler model Gray-Hoverman antenna has information that could be applied to building any GH antenna. https://www.instructables.com/id/Gray-Hoverman-TV-Antenna-Final-Assembly/
has within it links to the series of applicable Instructables.