The primary problem with the bow-tie design you used is the spacing between elements. At the low-end of UHF, the SWR (measure of how well power is transferred between antennas and cables) goes up and the overall gain of the antenna goes way down. At KERA's RF channel (14), there's almost as much signal power bouncing around the antenna as being delivered into the cable. Use the plans documented
here to improve KERA and have actual positive gain for channels 7-13, similar to or better than a dipole. You can even buy pre-made parts from the designer. Good luck!