I walk through a box of baluns I have known and love. Spoiler Alert: you may be induced to get some of your own
BALUN comes from “Balanced to Unbalanced” This usually means connecting a balanced load such as a dipole antenna to an unbalanced input such as a 50- ohm coaxial cable. The shield side of the cable is usually grounded.
BALUNS can also change impedance levels. For example, 4:1, or 200 ohm to 50 ohm or 300 ohm to 75 ohm.
UNUN means “Unbalanced to Unbalanced” This is a device inserted into a coaxial transmission line usually to reduce “common mode” currents – more on that later.
Your balun performs two important functions:
1. It provides a convenient connection interface between coaxial cable and either ladder line or a longwire antenna
2. It converts from an unbalanced source (e.g., a transmitter or tuner with coaxial output) to a balanced transmission line (e.g., ladder line)
In addition, the balun provides a 4:1 impedance conversion permitting use of higher impedance antennas and transmission lines for example
I have made a bunch of different pocket baluns all fairly small that fit into a pocket. I cleaned out the bins at Sayal for these little hammond boxes