Read the SW ALC meter (post-software-ALC SSB peak) on the Phone or CW panel

This page shows you how to monitor the software Automatic Level Control (ALC) meter, which reads the post-software-ALC SSB peak in dBFS. This meter helps you set your microphone gain or CW keying envelope so you transmit at an appropriate level without overdriving the audio chain.

Before you start

• Ensure your FLEX-8600 is connected and the active slice is in a voice mode (Phone) or CW mode.
• The Phone/CW applet must be visible in the right sidebar — toggle it on using the P/CW tray button if needed.

Steps

1. Locate the ALC gauge on either the Phone or CW sub-panel. It reads -20 to 0 dBFS, filling from right to left.
2. Key the transmitter (or, for CW, begin sending).
3. Watch the ALC gauge needle while you adjust your microphone gain with the Mic gain slider:
4. The meter is empty (at -20 dBFS) when no ALC is applied.
5. The gauge fills toward 0 dBFS as ALC increases.
6. The red zone begins at -3 dBFS (marked on the gauge).
7. For CW, the same ALC gauge appears on the CW sub-panel — it is identical and driven by the same meter source.

What each control does

Control	Label	Behavior	Valid range	Default	Setting key
ALC gauge (Phone panel)	ALC	Shows automatic level control reading from the software ALC meter (post-software-ALC SSB peak in dBFS). Fills right-to-left: empty at -20 dBFS, full at 0 dBFS. Red zone above -3 dBFS. Initialised to -20 dBFS on construction.	-20 to 0 dBFS	—	None
ALC gauge (CW panel)	ALC	Mirrors the Phone-panel ALC gauge; both read from the same software ALC meter for consistent readings across voice and CW. Initialised to -20 dBFS on construction.	-20 to 0 dBFS	—	None

What each Phone/CW control does

Control	Label	Behavior	Valid range	Default	Setting key
Level meter	Level	Shows microphone input peak level in dBFS (Phone panel). Suppressed to -150 when Level Meter During Receive is off and not transmitting.	-40 to +10 dBFS (red > 0)	—	None
Compression meter	Compression	Shows speech compression amount in dB (Phone panel). Gated on the radio's interlock TRANSMITTING state and speech processor enable: reads 0 dB during RX. Conversion: MeterModel exposes COMPPEAK as positive 0..25 dB, the gauge displays reversed -25..0 dB.	-25 to 0 dB (reversed fill)	—	None
Mic profile	Mic profile	Loads a named mic processing profile from the radio.	Populated from radio micProfileList()	—	None
Mic source	Mic source	Selects the microphone input source.	MIC, BAL, LINE, ACC, PC (plus any from micInputList())	—	None
Mic gain	Mic gain	Adjusts mic input level. For 'PC' source uses local PcMicGain persistence.	0-100	50	PcMicGain
+ACC	+ACC	Enables the accessory mic input mix.	—	—	None
PROC	PROC	Toggles the speech processor.	—	—	None
NOR/DX/DX+	NOR/DX/DX+	Three-position processor level.	0 (NOR), 1 (DX), 2 (DX+)	0	None
DAX	DAX	Enables DAX as the TX audio source.	—	—	None
MON	MON	Enables TX sidetone monitor.	—	—	None
Monitor volume	Monitor volume	Sets sideband monitor volume.	0-100	—	None
ALC gauge (Phone panel)	ALC	Shows automatic level control reading from MeterModel::swAlcChanged (post-software-ALC SSB peak in dBFS). Fills right-to-left: empty at -20 dBFS, full at 0 dBFS. Initialised to -20 dBFS on construction.	-20 to 0 dBFS (red > -3)	—	None
Delay (CW)	Delay (CW)	Sets CW break-in delay. The adjacent QLineEdit accepts typed values (0–2000).	0-2000 ms (step 10)	500	None
Speed (CW)	Speed (CW)	Sets CW keying speed. The adjacent QLineEdit accepts typed values (5–100).	5-100 WPM	20	None
Sidetone	Sidetone	Toggles CW sidetone monitor and the client-side low-latency CwSidetoneGenerator in lockstep. Routes to the user-selected audio output.	—	—	None
Sidetone volume	Sidetone volume	Sets CW monitor volume. Controls both radio-side (mon_gain_cw) and client-side sidetone volumes. The adjacent QLineEdit accepts typed values (0–100).	0-100	50	None
L / R pan (CW)	L / R pan (CW)	Sets CW monitor stereo pan. Applies constant-power pan to the local sidetone generator. Double-click recenters to 50 (centre).	0-100	50	None
Breakin	Breakin	Toggles full break-in (QSK). With Breakin ON key edges trigger TX; with Breakin OFF keys are queued and the operator engages PTT manually.	—	—	None
Iambic	Iambic	Toggles iambic paddle keyer.	—	—	None
Pitch < / >	Pitch < / >	QLineEdit with < / > buttons. Type a value (100–6000) or click the buttons to step by 10 Hz.	100-6000 Hz (step 10)	600	None
ALC gauge (CW panel)	ALC	Mirrors the Phone-panel ALC gauge; driven from the same software ALC meter. Initialised to -20 dBFS on construction.	-20 to 0 dBFS (red > -3)	—	None

Notes

• In v26.5.3 both ALC gauges are initialised to -20 dBFS on construction, preventing a momentary full-scale reading at startup.
• The Compression gauge in v26.5.3 uses the MeterModel COMPPEAK value (positive 0..25 dB) and inverts it for the reversed -25..0 dB gauge display.
• The level meter suppression logic has been refactored in v26.5.3 into a dedicated applyLevelMeterReceiveGate() method, called when transmit state changes or the RADE active state changes.
• In v26.6.1 slider styling was updated to use the theme system instead of hardcoded color values. All sliders in the Phone/CW applet now respect the current theme.

Related

• Adjust mic gain and enable the accessory mix
• Set CW keying speed in WPM