Practical answer: Measure VHF/UHF SWR at the reference plane that answers the question: the radio end checks what the transmitter sees; the antenna end isolates antenna match from feed-line effects.
What changes on the air
Lossy coax can make station-end SWR look better by attenuating both forward and reflected waves. That does not improve the antenna or recover lost signal.
Plan the installation
- Calibrate the instrument with the final test leads.
- State frequency and measurement plane.
- Use the shortest practical test fixture at the antenna.
- Save a sweep, not one favorable point.
Common mistakes
- Comparing traces from different planes.
- Calling low station-end SWR efficient.
- Ignoring adapter and jumper effects.
Technical boundary
General VHF/UHF antenna and transmission-line practice. Use the current product guide for exact dimensions, ratings, connectors, mounting, and supported configurations.
