Pick a mic source (MIC, BAL, LINE, ACC, PC)¶

Select which physical or virtual input the radio uses as the microphone source for voice transmissions. The choice determines where the FLEX-8600 takes its TX audio from — the front-panel mic connector, balanced input, line input, accessory port, or the PC's audio system.

Before you start¶

AetherSDR must be connected to a FLEX-8600 radio.
The active slice must be in a phone mode (USB, LSB, AM, FM, etc.). The Phone/CW applet shows the Phone sub-panel automatically in voice modes.

Steps¶

Click the P/CW tray button in the right sidebar to open the Phone/CW applet.
Locate the Mic source drop-down box in the Phone sub-panel.
Click Mic source and select one of the available sources: MIC, BAL, LINE, ACC, or PC.

The selection takes effect immediately on the radio.

What each control does¶

Control	Description	Default
Mic source	Selects the microphone input source sent to the radio.	—
Mic gain	Adjusts the microphone input level. When the source is `PC`, or when RADE mode is active, the value is stored client-side in `PcMicGain` because the radio does not manage gain in those paths.	50

Source descriptions:

MIC — Front-panel microphone connector.
BAL — Balanced microphone input.
LINE — Line-level input.
ACC — Accessory port microphone input.
PC — Computer audio system. The radio does not report mic level for this source; AetherSDR stores the gain value locally in PcMicGain.

RADE mode and mic gain¶

When RADE mode is active, the Mic gain slider acts as a client-side RADE gain control rather than sending a mic level command to the radio. The slider value is stored in PcMicGain, the same setting used for the PC source. Moving the slider does not overwrite the radio's hardware mic level setting while RADE is active.

The Level meter remains active during receive when RADE is on. This allows you to monitor input level between transmissions without enabling met_in_rx on the radio.

When RADE mode is deactivated, the slider reverts to the radio's reported mic level and the Level gauge resets to −150 dBFS until a new meter value arrives.

CW sidetone controls (v0.9.1+)¶

When the active slice is in a CW mode, the applet switches to the CW sub-panel. The Sidetone toggle and Sidetone volume slider control both the radio's DAX-fed monitor and the client-side low-latency sidetone generator (~10 ms latency) in lockstep. There are no separate local sidetone controls; a single set of controls governs both paths.

Control	Description	Default	Valid values	Setting key
Sidetone	Enables or disables CW sidetone. Controls both the radio's DAX-fed monitor and the client-side sidetone generator simultaneously.	—	On / Off	—
Sidetone volume	Sets the sidetone volume for both the radio side (`mon_gain_cw`) and the client-side generator.	—	0–100	—
L / R pan (CW)	Sets stereo pan for the CW monitor and applies constant-power pan to the local sidetone generator. Double-click to recentre at 50.	50	0–100	—
Pitch < / >	Steps the CW sidetone and decode pitch by 10 Hz.	600 Hz	100–6000 Hz	—

Pitch and pan always follow the radio's cw_pitch and mon_pan_cw settings automatically. There is no separate "Follow" toggle or manual pitch override slider; those controls were removed in v0.9.2.1.

Tips¶

When using PC as the source, the Level meter appears immediately when AetherSDR connects to the radio, because PC mic metering runs client-side independently of the radio's met_in_rx setting. The meter is not suppressed between transmissions for PC sources.
When RADE mode is active, the Level meter also runs client-side and is not suppressed between transmissions, regardless of the met_in_rx setting. This matches the behavior of the PC source.
To mix in the accessory port alongside your primary source, enable the +ACC toggle button after selecting your main source.
At higher CW speeds, the client-side sidetone path (~10 ms latency) is more usable than the radio's DAX-fed monitor. Because the Sidetone toggle controls both paths together, enabling sidetone always activates the low-latency path automatically.
When VOX is toggled via keyboard shortcut, the Phone panel refreshes instantly to reflect the new VOX state (v0.9.3).
On Windows, the CW sidetone stream starts immediately on connect (v0.9.3). If sidetone is enabled before connecting, no additional steps are required after the connection is established.
The Compression gauge reads 0 dB during receive. This is intentional: in v0.9.7 the gauge is gated on the radio's interlock TRANSMITTING state, so stale TX chain readings are not displayed between transmissions.
The Breakin button fully honors the radio's break_in setting as of v0.9.7. With Breakin on (QSK), key edges trigger TX and the break-in delay holds the relay. With Breakin off, keys are queued and PTT must be engaged manually. The previous behavior, where an auto-PTT envelope masked the Breakin off state and interfered with QSK hang time, has been removed.

Troubleshooting¶

Mic source combo shows no selection or resets — The list is populated from the radio's reported inputs. If the combo is empty, verify the radio connection is active (Settings > Connect to Radio...).
Level meter reads nothing when source is PC — This is not expected behavior in v0.9.3. The Level gauge should appear immediately on connect when the mic source is PC. If it does not, verify that AetherSDR is running v0.9.3 or later. For non-PC sources, the meter is suppressed to −150 dBFS when not transmitting and met_in_rx is off; this is normal.
Level meter reads nothing when RADE is active — The Level gauge should remain active during receive when RADE mode is on, independently of met_in_rx. If the gauge is not updating, verify that AetherSDR is running v0.9.7 or later.
Mic gain slider resets to 100 when RADE activates — RADE mode and the PC source both use the PcMicGain setting. If you have not previously set a value for PcMicGain, the slider defaults to 100 when RADE becomes active. Adjust the slider to your preferred level; the value is stored immediately.
Sidetone pitch does not match expectation — Pitch follows the radio's cw_pitch setting automatically. Adjust pitch using the Pitch < / > spinbox, which writes directly to the radio.
Sidetone does not start on connect (Windows) — This was a known issue in versions before v0.9.3 caused by AudioEngine initialization order. Update to v0.9.3 or later to resolve it.
Compression gauge shows a value during receive — This should not occur in v0.9.7. The gauge is gated on the radio's interlock TRANSMITTING state and reads 0 during RX. If you see a non-zero reading while receiving, verify that you are running v0.9.7 or later.
Breakin off does not prevent TX on key press — This behavior was corrected in v0.9.7. Update to v0.9.7 or later. In earlier versions, an internal auto-PTT envelope could force TX regardless of the Breakin setting.