here is another shot of a custom hack, a dual yagi cut for ch7 but the same guy who did the cm4221 mated to a parabola refelctor hack

http://www.redshift.com/~1king26/DUALYAGI.JPG

That antenna looks very peculiar -- not a yagi pattern and the little stubs look strange as well. And if it is intended to be oriented as shown in the photo, then the polarization is wrong for North America -- maybe this guy is in Oz ?

EDIT: mm.. the little stubs look like impedance-matching tubes, kinda like the coax-loop baluns I use. But how they connect to the "dual yagi" isn't clear from the photo.

Those are gamma matches they come in real handy when you want to have the ability to change the impedence match of an antenna. They usually have a narrow band with but they work good for single channel yagis no need for the transformer balun just attach the coax direct. Some are made with a sliding tube inside so you can tune them by sliding the tube in or out.

the creator expressed that it was another type of antenna, ham related, and he hacked it for USA ch7 purposes