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Monitor Forward Power and SWR at the Amplifier Output

The Amplifier applet shows live forward power and SWR readings from a connected Power Genius XL (PGXL) amplifier. Use these meters to confirm output power and antenna match during transmit.

Before you start

  • AetherSDR must be connected to a Flex radio.
  • A Power Genius XL amplifier must be detected by the radio. The AMP tray button does not appear until the PGXL is present.

Steps

  1. Locate the AMP tray button on the right sidebar of the applet panel.
  2. Click AMP to open the Amplifier applet.
  3. Transmit. Watch the Fwd Pwr and SWR meters update in real time.

What each control does

Control What it shows Range
PWR Forward power at the PGXL output 0–2000 W (red > 1500)
SWR Standing wave ratio at the PGXL output 1.0–3.0 (red > 2.5)
Id Drain current 0–70 A (red > 60)
Temp PGXL heatsink temperature 0–100 °C (red > 80)
Volts / Amps Mains voltage and drain current text integer volts, 1 decimal amp
MEffA PGXL amplifier efficiency metric —
Fan speed Cycles fan speed modes STANDARD / CONTEST / BROADCAST
OPERATE Toggles amplifier between OPERATE and STANDBY —

All three bar gauges (PWR, SWR, Id) display as horizontal bar gauges with a left-side label showing the field name and live value (e.g., "PWR 1148"). The filled bar turns red when the value enters the red zone. Tick labels are drawn along the top of each gauge at the following reference points:

  • PWR: 0, 500, 1000, 1.5K, 2K
  • SWR: 1, 1.5, 2, 2.5, 3
  • Id: 0, 10, 20, 30, 40, 50, 60, 70

The PWR gauge has slow-release ballistics: the bar rises quickly on RF bursts but decays over approximately 800 ms, so brief transmissions remain visible. This matches the S-meter peak-hold feel.

None of the meters have a persisted settings key. Values are read-only telemetry from the PGXL.

SWR gauge behavior: The SWR gauge only updates when forward power is at least 5.0 W. When forward power drops below 5.0 W, the SWR gauge resets to 1.0. This prevents stale or noise values from being displayed when the amplifier is idle.

Vdd label behavior: When drain supply voltage (Vdd) drops below 1.0 V (indicating the drain supply is off during STANDBY), the Vdd label shows "Vdd — V" instead of "Vdd 0.0 V" for clarity.

Fan speed button: The fan speed button appears only after a direct PGXL connection delivers the first fan mode status. Click the button to cycle through STANDARD, CONTEST, and BROADCAST. The button displays a single letter: S (STANDARD), C (CONTEST), or B (BROADCAST).

Tips

  • The bar gauges use smoothed animation. A brief lag between the actual value and the displayed bar is normal during fast-changing conditions such as the start of a transmission.
  • If SWR enters the red zone (above 2.5), check your antenna system before continuing to transmit at high power.
  • The drain current (Id) gauge helps monitor amplifier health. If Id exceeds 60 A, consider reducing drive power.
  • The MEffA field shows the PGXL amplifier efficiency metric. This field is hidden until telemetry arrives.
  • The Volts / Amps text label is hidden until the first telemetry arrives.

Troubleshooting

  • AMP tray button is not visible — The PGXL has not been detected by the radio. Verify the amplifier is powered on and connected to the Flex radio. AetherSDR shows the AMP button only after the radio reports an amplifier is present.
  • PWR and SWR meters show no movement during transmit — Confirm the amplifier is in OPERATE state, not STANDBY. See Put the PGXL amplifier in OPERATE.
  • Fan speed button does not appear — A direct PGXL connection is required. The button becomes visible only after the first fan mode status is received from the amplifier.
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