One of the easiest and quickest antennas to build is the Vertical Bazooka, which is made entirely from coaxial cable.
Category: Homebrew
7 element Yagi for 20 Meters band
Yagi Antenna for 20 Meters band
The 9:1 Balun
A homebrew 9:1 Balun experience
Raspebrry PI for the new year
Starting with a new ham radio toy in my shack. The Rasperry PI