These baluns and ununs can be used for impedance matching and also as End Fed halfwave antenna matching transformers to 50 or 75 ohm coax cable.
Complete Antenna Systems
Choose from OCF, Vertical, Loops, Zepps, end feds using Palomar Engineers Over-Engineered to Outperform(TM) impedance transformers and feed line chokes for outstanding antenna performance!
Palomar Engineers Antenna Info Sheet