An original project by I0QM of a 7 element yagi anetnna in a PDF File.
The QM7 antenna is a simple 7 elements Yagi with 3.7 m boom length for the lower 144 MHz
SSB/MGM band
forward gain is 1.35 dBd; i.e. 13.5 dB forward gain over the isotropic radiator, while the F/R is about 12.5 dB