If your area has no channels 2 through 6, this antenna becomes a top candidate. It matches the performance of much larger LPDAs. Winegard calls it a “wideband Yagi”. It is actually a Yagi/LPDA hybrid, a Log-Yag. The directors optimize channel 13, while the reflector is cut for channel 7.
If you are good at metalworking, adding more directors increases the gain. Each doubling of the length of the boom adds up to 3 dB to the gain. The author uses one that is 24-feet long.
(Note: The pattern graphs above plot the raw gain, thus they overstate the performance on channels 3 and 5. This antenna has nearly no detectable performance below channel 7.)
This page is part of “An HDTV Primer”, which starts at www.hdtvprimer.com