In plain language: A balun is a network that interfaces a balanced circuit with an unbalanced circuit and may also transform impedance, depending on its design ratio and construction.
Why the station behaves this way
Voltage and current baluns behave differently, usable impedance and frequency ranges are finite, and core heating depends on mismatch, power, duty cycle, and common-mode voltage.
A common wrong turn
Choosing a balun only from a printed ratio can produce poor choking, core saturation, or an impedance transformation the antenna never needed.
What to do at the radio
Identify the source and load balance, expected impedance range, frequency, power and duty cycle, required common-mode isolation, then use the exact maker’s data and test the installed system.
Operating boundary
Use current equipment instructions, legal operating limits, the exact signal path, and observed conditions. A connector, software label, transformer ratio, or forecast value does not prove complete-system performance.
