First Tune-Up

It tunes on 20, reads 3:1 on 17, and 15 won't settle. Is something wrong?

Short answer: no. That is a vertical dipole before the tuner is in the picture, and it is working. Here are the six things that turn those readings into every band, 160 through 6. Most installs need one or two of them; almost none need a phone call.

1. The tuner must be wide-range

The tuner built into a radio handles about 3:1 and quits; that is the limit most people hit. You need a wide-range tuner, in the shack or at the antenna. Both work and thousands of owners run each. A good shack-side external tuner works fine; so does a remote tuner at the base. Shack or remote, explained →

2. The ladder line is part of the antenna. Get it off the ground.

The ladder line from the feedpoint is not just a wire to the tuner; it is carrying balanced current and it behaves like part of the radiator. Lying on dirt or grass, it couples to the earth and the readings go sideways. Keep it off the ground — to test, set the adapter end on a chair or a bucket — and run it straight up and away from the pole, fences, and anything metal, with the spacers holding the two wires apart. Air is its friend.

3. All five ferrites, pushed up against the connector

The five snap-on ferrites in the kit go on the coax at the adapter end, stacked side by side and pushed right up against the connector. That is your choke. It keeps RF off the outside of the coax so the feedline stops acting like a third element. Five at the connector, none spread down the line. If a remote tuner sits at the base, the choke goes on the radio side of the tuner instead. Where the choke goes, with pictures →

4. The longer element goes to the coax center conductor

The antenna is an off-center-fed dipole: a longer element above the feedpoint and a shorter one below. The longer element should connect, through the ladder line and the adapter, to the center conductor of the coax. Easy to check with an ohmmeter from the coax center pin to the upper tube. If it reads to the lower tube instead, swap the red and black ladder-line leads at the adapter and retune. One polarity tunes noticeably easier on 40 and 80; that is the right one.

5. How long is the coax, and how thin?

Small-diameter coax on a long run adds loss, especially above 20 meters. It is worth fixing — LMR-400 class is the sweet spot at HF — but it is never the root of a major tuning problem. If the antenna will not load on a band, the coax is not why. See what your run costs you →

6. Clear the tuner's memories and let it learn

A new antenna means new impedances on every band. If your tuner stores settings, the old ones are wrong by definition. Clear them, then tune each band once from scratch and let it remember the new ones. Adding the 9' whip later? Clear and retune again.

Related: Assembly Quick Card · Low SWR, still losing signal? · Do I need to ground it?

Ham Radio is fun again! Pass it on... 73, Jon KL2A