EV>So a Quagi looks like it has two square reflector sections instead of
EV>reflector elements?
EV>I would guess that them being of a larger size helps the Front to Back
EV>Ratio?

Actually one of the "Square" elements is the Active radiating element
connected to the coax cable and the one of the reflector.

EV>As I was typing near the end of this message I remembered a SQUALO
EV>Antenna, if I spelled it right, and just had to write about it.
EV>I think it was a Square Halo antenna way back in the 1960's for 6M and
EV>maybe 2M. It's been a L O N G time since I've thought about those.

You could consider the Quagi a verticaly polarized SQUALO with
directors and a reflector.
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 þ SLMR 2.1a þ 0