KN4YZY

Yesterday we tuned up the IC-7300. Today it’s the Yaesu FT-991A’s turn. The 991A has its own automatic antenna tuner for HF and 6 meters, and once you know what the TUNE key is telling you, it takes just a few seconds.

Level: Beginner  |  Time: About 10 minutes  |  Note: The tuner only works on HF and 6 meters. It does nothing on 2 meters or 70 cm, so those antennas need to be a good match on their own.

What You’ll Need

• Your FT-991A connected to an HF antenna on the HF/50 MHz antenna jack
• A clear frequency (listen first, then ask if it’s in use)
• Optional: an inline SWR/power meter if you like to double-check the radio’s own meter

Step 1: Watch the SWR

Set the meter to show SWR (the meter selection is in the radio’s function menu). Turn the power down to around 10 watts and key up briefly in a steady-carrier mode like CW or RTTY. Under 1.5:1 is great, and you don’t need the tuner. Up to about 3:1, the tuner can handle it. Above that, it’s an antenna problem.

Step 2: Quick Press to Turn It On

A quick press of TUNE turns the tuner on, and the TUNE indicator shows on the display. If the radio has already tuned this part of the band before, that’s all you need. It pulls the setting from memory.

Step 3: Long Press to Tune

1. Press and hold TUNE. The radio transmits a short carrier and you’ll hear the relays clicking as it searches for a match.
2. When it finishes, the TUNE indicator stays lit and the setting is saved for that part of the band.
3. Key up briefly and check the SWR again. It should be close to 1:1.

The saved settings cover a fairly narrow slice of the band, so if you move a good distance, or change antennas, do the long press again.

Step 4: Read the Warning Sign

If you hold TUNE, hear just one click, and the TUNE indicator doesn’t come on, the radio is telling you the SWR is too high for the internal tuner. That’s your cue to check the antenna and feedline, or use an external tuner built for wider matching.

Gotchas

• Expecting it to work on VHF/UHF. It doesn’t. On 2 meters and 70 cm, the antenna has to be a good match by itself.
• Tuning on top of a QSO. The tuner transmits. Listen and ask before every long press.
• Using the tuner to hide a problem. If the SWR jumped since last time, find out why before you tune it away. A loose connector or wet coax will only get worse.

Your Turn

Which band gives your FT-991A’s tuner the hardest time? Let me know in the comments, and ask any Yaesu question there too. Last Tuesday’s post on programming a local repeater on the FT-991A is a good next read, and there’s more on the Weekly How-To page.

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