50 ohms feed
23cm or 70cm Corner Slots
Design by G8ADM
An interesting alternative to the Alford Slot and probably easier to make.
This is the most popular aerial for TV use. Its directional ability makes for high gain but at the expense of beamwidth. This means that unless used to contact a repeater only, it will need a rotator to point to other stations.
Reasonably simple to build and measurements only become critical at higher frequencies.
A corner slot or Alford slot give lower gain but receives over 360 degrees.