Run an Autotune on the External TGXL¶
This page explains how to start an automatic tuning cycle on a connected 4O3A Tuner Genius XL. Use autotune to find the best C1/L/C2 relay combination for your current frequency and antenna.
Before you start¶
- A Tuner Genius XL must be detected by AetherSDR. The TUN tray button appears on the right sidebar only when a TGXL is present.
- The radio must be connected. The Tuner applet requires an active radio connection.
- The TGXL should be in OPERATE state (button shows "OPERATE" in green). Autotune will not produce a useful result if the tuner is in BYPASS or STANDBY.
Steps¶
- Click the TUN tray button on the right sidebar to open the Tuner applet.
- Confirm the OPERATE button shows "OPERATE" (green). If it shows "BYPASS" or "STANDBY", click it until "OPERATE" appears.
- Click TUNE.
- Wait while the button turns red and reads "TUNING...". Do not transmit manually during this time.
- When tuning completes, the button briefly displays the result — for example, "SWR 1.42" — for approximately 2.5 seconds, then returns to "TUNE".
- Check the SWR gauge to confirm the final settled SWR value.
What each control does¶
| Control | Description | Valid range |
|---|---|---|
| TUNE | Starts the autotune cycle. Turns red and reads "TUNING..." while active. Flashes the post-tune SWR for 2.5 seconds when complete, then resets to "TUNE". Since v0.9.2.1, when a direct TGXL connection (port 9010) is configured, sends the native "autotune" command directly to the TGXL instead of routing through the radio's firmware path. Configure this in Radio Setup → Tuner. Falls back to the radio path when no direct connection is available. | — |
| OPERATE | Cycles the tuner state: OPERATE (green) → BYPASS (orange) → STANDBY → OPERATE. Must be in OPERATE for a meaningful tune. | — |
| ANT 1, ANT 2, ANT 3 | Selects antenna port 1, 2, or 3 on the TGXL 3x1 switch. Row hidden unless direct TGXL connection is active and the antenna switch is present. | — |
| Fwd Pwr | Displays TGXL-reported forward power. Scale depends on your configuration: 0–200 W barefoot, 0–600 W Aurora, 0–2000 W with PGXL. Gauge features ballistic behavior: bar rises quickly on RF bursts but decays over approximately 800 ms. Peak hold marker (white tick) appears at the highest forward power observed; clears after 2.5 seconds of no new peaks. When forward power is below 5 W, the gauge reads zero to prevent idle noise from lighting the bar. | 0–2000 W |
| SWR | Displays TGXL-reported SWR. Gauge turns red above 2.5. When forward power is below 5 W, the SWR gauge snaps to 1.0 (empty) to prevent idle noise readings from lighting the bar. The gauge updates normally when forward power is 5 W or higher. | 1.0–3.0 |
| C1 | Shows the C1 relay bank position; mousewheel scroll adjusts the relay when direct TGXL connection is active. Accessible name: "Tuner capacitor C1". | 0–255 |
| L | Shows the L relay bank position; mousewheel scroll adjusts the relay when direct TGXL connection is active. Accessible name: "Tuner inductor L". | 0–255 |
| C2 | Shows the C2 relay bank position; mousewheel scroll adjusts the relay when direct TGXL connection is active. Accessible name: "Tuner capacitor C2". | 0–255 |
Tips¶
- The SWR displayed on the TUNE button after tuning reflects a settled value captured up to 400 ms after the tuning cycle ends. This is the final TGXL-reported figure, not a mid-sweep reading.
- If you need to read the post-tune SWR after the 2.5-second flash has expired, watch the SWR gauge directly.
- The Fwd Pwr gauge features "ballistic" behavior: the bar rises quickly on RF bursts but decays over approximately 800 ms, providing a smooth reading.
- A peak hold marker (white tick) appears on the Fwd Pwr gauge at the highest forward power level observed. It clears automatically after 2.5 seconds of no new peaks.
- The SWR gauge is automatically set to 1.0 when forward power is below 5 W, preventing idle noise from showing a false high SWR reading.
Troubleshooting¶
- The TUN tray button does not appear — AetherSDR has not detected a TGXL. Check that the tuner is powered on and communicating with the radio or directly with AetherSDR.
- TUNE button returns to "TUNE" immediately without showing an SWR result — The tuner may not have been in OPERATE state, or the tuning cycle completed with no valid SWR data returned. Confirm the OPERATE button shows "OPERATE" (green) before clicking TUNE.
- SWR gauge reads red (above 2.5) after tuning — The tuner could not find a satisfactory match. Check antenna connections and confirm you are within a band the antenna covers.
- SWR gauge shows 1.0 even when you expect a higher reading — Check that your forward power is above 5 W. The SWR gauge is designed to show 1.0 (empty) whenever forward power is below 5 W to prevent idle noise from lighting the bar.