Start with the practical answer: Diagnose a transformer, balun, unun, or loading coil only after proving the feed line and complete geometry; inspect heat, arcing, cracked insulation, loose contacts, water, ratio/topology errors, and power or duty-cycle overload.
What changes the result
Separate the station into power/source, feed line, matching, radiator, return, environment, and propagation so one symptom is not mistaken for another.
The mistake to avoid
Do not transmit into an uncertain, arcing, hot, unstable, or exposure-unsafe system, and do not use a tuner to hide an unresolved fault.
Use this operating sequence
Capture a known-good baseline, remove RF, restore the exact configuration, inspect and measure from radio outward, substitute one known-good part at a time, then document the correction.
Source boundary
Current controlled CKB RF engineering, VHF/UHF, operating, and diagnostic references. Confirm current local coordination, band plans, satellite data, and equipment documentation before operating.
