Tuner Tips – by Dan, N5AR

This is a short but important tip on how to best use your manual antenna tuner. If you are adjusting your tuner for the lowest SWR at its input, you are probably not using it in the optimum manner. By far the most loss in your tuner is in the inductor. The variable capacitors are nearly lossless. Have you ever looked inside one of the tuners using Air-Dux or similar coils which has had considerable use? It is not unusual to see the coil is distorted. This is due to over heating. Tuners using rotary inductors sometimes show burn marks on the traveling roller contact. I have seen quite a few tuners like this at ham flea markets. This is particularly a problem when matching short antennas on 80 or 160 meters. Many of the commercial tuners, which are OK on the higher bands, cannot handle legal power on the low bands

Here is how to adjust the tuner for lower loss.

  1. Tune for lowest SWR with low power.
  2. Reduce the inductance and retune for the lowest SWR.
  3. Look for the lowest inductor setting which still gives an acceptable SWR.

That’s all there is to it. 73, Dan, N5AR