Enable speech processor at NOR, DX, or DX+ level¶

Turn on the FLEX-8600's built-in speech processor and choose how aggressively it compresses your transmitted audio. NOR gives mild compression; DX and DX+ increase processing for weaker-signal contacts.

Before you start¶

AetherSDR must be connected to the radio.
The active slice must be in a phone mode (USB, LSB, AM, etc.). The Phone/CW applet shows Phone controls only when the active slice is not in CW mode.
Open the Phone/CW applet by clicking the P/CW tray button on the right sidebar if it is not already visible.

Steps¶

In the Phone/CW applet, click PROC to enable the speech processor. The button lights green when active.
Drag the NOR/DX/DX+ slider to the desired compression level:
Position 0 — NOR (normal, least compression)
Position 1 — DX
Position 2 — DX+ (most compression)
Watch the Compression gauge. The reversed fill shows how many dB of compression is being applied (range: −25 to 0 dB). Keep the reading out of the far left to avoid over-processing.
Watch the Level gauge to confirm microphone input is reaching the processor. The range is −40 to +10 dBFS; the meter goes red above 0 dBFS.
Watch the ALC gauge (Phone panel) to confirm the post-software-ALC level is in the normal operating range (−20 to 0 dBFS). The gauge fills from the right; excessive ALC pins at 0 dBFS.
To disable the processor, click PROC again. The button returns to its unlit state.

What each control does¶

Control	Kind	Default
PROC	Toggle button	Off
NOR/DX/DX+	Slider	0 (NOR)
Level	Meter	—
Compression	Meter	—
ALC (Phone panel)	Meter showing 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.	Rewired from HWALC (RCA voltage) to SW ALC meter in v26.5.1 (#2552). Mirrored by an identical gauge on the CW sub-panel.
ALC (CW panel)	Meter mirroring the Phone-panel ALC gauge; both read from MeterModel::swAlcChanged for consistent readings across voice and CW. Fills right-to-left: empty at -20 dBFS, full at 0 dBFS.	Added in v26.5.1 (#2552) as part of the SW ALC meter split. Uses HGauge::setFillFromRight mode.

Tips¶

Set your mic gain before enabling the processor. A healthy Level reading before enabling PROC gives the processor useful signal to work with. See Adjust mic gain and enable the accessory mix.
Start at NOR and move to DX or DX+ only if signal reports warrant it. Heavy processing on strong signals sounds distorted to the receiving station.
The Compression gauge reads 0 dB (no fill) when PROC is off, when the radio is not transmitting, or when no audio is present.
Both ALC gauges (Phone and CW panels) use the same software ALC meter source. For SSB operation, target −10 to −5 dBFS on the ALC gauge for optimal transmit audio quality.

Troubleshooting¶

PROC button is not visible — The applet is showing the CW panel. The Phone panel, including PROC, appears only when the active slice is in a phone mode, not CW.
Compression gauge shows 0 dB with PROC on — In v0.9.7 and later the Compression gauge is gated on the radio's interlock TRANSMITTING state: it intentionally reads 0 dB during receive to prevent stale readings from the TX chain. If the gauge still reads 0 dB while transmitting, the radio is not receiving audio from the selected mic source. Check the Level gauge and the Mic source setting. If Mic source is PC, the radio always reports mic level as 0; use the Level gauge in the applet instead.
NOR/DX/DX+ slider snaps back — The slider has three valid positions (0, 1, 2). Dragging between snap points causes it to land on the nearest integer; this is expected behavior.
Level gauge does not appear on connect — If Mic source is PC, the Level gauge appears immediately on connect without requiring a transmit or met_in_rx to be active (v0.9.3, fix #2086). When RADE mode is active, the Level gauge also appears during receive (see Level gauge behavior). If the gauge is still absent, verify that Mic source is set to PC and that AetherSDR has finished connecting to the radio.
Phone panel does not refresh when VOX is toggled by keyboard shortcut — This was resolved in v0.9.3 (#2084). Update to v0.9.3 or later if the Phone panel fails to update immediately when VOX is toggled via a keyboard shortcut.
ALC gauge shows unexpected values — The ALC meters now read from the software ALC meter (MeterModel::swAlcChanged) in dBFS ranges. Values outside −20 to 0 dBFS are not displayed; the gauge simply pins at the nearest end. This replaces the previous HWALC path that produced meaningless readings.

CW panel controls (v0.9.8)¶

In v0.9.8, the four value labels for CW parameters were replaced with QLineEdit widgets. The adjacent sliders and buttons remain unchanged. Click any value and type a number directly to set it. Values are clamped to the valid range when you press Enter or Tab.

Control	Kind	Default	Valid range
Delay (CW)	Slider + edit	500	0–2000 ms
Speed (CW)	Slider + edit	20	5–100 WPM
Sidetone volume	Slider + edit	50	0–100
Pitch < / >	Text + buttons	600	100–6000 Hz

The Delay (CW), Speed (CW), and Sidetone volume QLineEdit widgets use QIntValidator to restrict input to the valid range.
The Pitch < / > widget (CwTriBtn) allows typing a value (100–6000) or clicking the < / > buttons to step by 10 Hz.
The Delay (CW) slider was fixed in v0.9.8 (#2428) so that setCwDelay caches the value immediately, preventing the radio emission from snapping the slider back.
The Sidetone volume slider controls both the radio-side (mon_gain_cw) and client-side sidetone generator volumes in lockstep.

CW sidetone behavior (v0.9.1 and later)¶

The Sidetone toggle and Sidetone volume slider in the CW panel control both the radio's DAX-fed monitor and the client-side low-latency sidetone generator in lockstep. There is no longer a separate Local STn button, separate local volume slider, or Follow pitch toggle. Those controls have been removed.

Enabling Sidetone turns on both the radio-side monitor and the client-side generator simultaneously.
Adjusting Sidetone volume sets both mon_gain_cw on the radio and the local generator volume to the same value.
Pitch and stereo pan always follow the radio's cw_pitch and mon_pan_cw settings automatically. No manual override or follow toggle is needed.
On Windows, the sidetone audio stream now starts immediately on connect rather than requiring a manual action (v0.9.3, fix #2105).
The sidetone bus is shared with Quindar tones. Sidetone and Quindar tones are mutually exclusive at the mode level.
In v26.5.3, the CW sidetone routes to the user-selected audio output device instead of the default output device (#2899). No user action is required; the sidetone automatically follows the audio output selection in the application's audio settings.

If you have settings from a previous version that reference CwLocalSidetoneEnabled, CwLocalSidetoneVolume, CwLocalSidetonePitchFollow, or CwLocalSidetonePitchHz, those keys are no longer read or written by AetherSDR and can be ignored.

Break-in behavior (v0.9.7)¶

The Breakin toggle now fully honors the radio's break_in setting.

With Breakin on (QSK mode), key edges from the CW keyboard or MIDI keyer trigger transmit immediately; the break_in_delay value holds the relay open between characters as expected.
With Breakin off, keyed characters are queued and the operator engages PTT manually. The previous auto-PTT envelope that forced transmit regardless of this setting, and that eliminated QSK hang time, has been removed.

ALC gauge behavior (v26.5.1)¶

Starting with v26.5.1 (#2552), both the Phone panel and CW panel ALC gauges read from the software ALC meter (MeterModel::swAlcChanged) rather than the hardware ALC (HWALC) RCA voltage path. The HWALC path produced meaningless readings; the new path provides meaningful post-software-ALC SSB peak values in dBFS.

Both gauges display a range of −20 to 0 dBFS.
The fill direction is right-to-left: the gauge appears empty at −20 dBFS and fills toward the left as the level increases, reaching full at 0 dBFS.
Excessive ALC pins at 0 dBFS.
The gauges are mirrored: adjusting mic gain affects both gauges identically when operating in the respective mode.
The gauges use HGauge::setFillFromRight(true) for proper visual rendering.

Level gauge behavior (v0.9.3)¶

When Mic source is set to PC, the Level gauge uses client-side metering and is not suppressed by the radio's met_in_rx flag. The gauge appears immediately on connect and shows the PC microphone input level whether or not the radio is transmitting.

When RADE mode is active, the Level gauge behaves the same way: it uses client-side metering and is not suppressed by met_in_rx, so it shows the RADE input level during receive as well as transmit.

For all other mic sources with RADE inactive, the gauge is suppressed to −150 dBFS when met_in_rx is off and the radio is not transmitting.

Level gauge behavior (v26.5.3)¶

In v26.5.3, the logic that suppresses the Level gauge during receive has been refactored into a dedicated applyLevelMeterReceiveGate() method. This replaces the inline suppression check in updateMeters(). The behavior is functionally identical to previous versions:

When met_in_rx is off and the radio is not transmitting, the Level gauge is set to −150 dBFS regardless of the mic source. The previous exception for PC mic source and RADE mode has been removed — those sources are now also suppressed during receive when the level meter during receive is disabled.
To show the Level gauge during receive for PC mic source or RADE mode, enable Level Meter During Receive in the radio's settings or the applet's settings.

RADE mode behavior (v0.9.7)¶

When AetherSDR activates RADE mode, the Phone/CW applet adjusts several behaviors automatically. No manual steps are required.

The Mic gain slider acts as a client-side RADE gain control. Its value is stored in PcMicGain and is not sent to the radio as mic_level. This prevents the slider from silently overwriting the hardware mic setting on the radio.
The PcMicGain setting is shared between PC mic source and RADE mode. Both paths are client-authoritative; the radio does not report a mic level for either.
The Level gauge shows RADE input level during receive (client-side metering, not gated by met_in_rx).
When RADE mode deactivates, the applet resynchronizes the Mic gain slider from the radio's reported value, and the Level gauge reverts to standard suppression behavior for the active mic source.

Compression gauge behavior (v26.5.3)¶

In v26.5.3, the Compression gauge calculation was updated to correctly interpret the raw COMPPEAK meter value from MeterModel. The gauge now expects a positive value (0–25 dB compression) and inverts it for the reversed-fill gauge display.