Working on optimizing my FT8 setup to eliminate spurious emissions. Currently running IC-7300 with WSJT-X 2.6.1. I understand the importance of avoiding ALC activation, but I'm getting conflicting advice on proper audio drive levels.

The document advises how to set the transmit levels to drive the radio without causing ALC and generate harmonics, including understanding the ALC meter and setting the radio power, audio input level, and external sound card if used. It recommends setting the radio bandwidth as wide as possible, from 200Hz-3000Hz or up to 5000Hz if the radio allows.

What's the optimal approach for setting Windows audio levels vs WSJT-X power slider vs radio ACC/USB output level?

If you are using an IC-7300, use the ACC/USB IF Output level (default is 50) to control the audio level sent to your computer. Keep WSJT-X power slider at 100% and adjust the radio's ACC level until ALC just doesn't activate.

For RX, set audio device levels to 100%, disable AGC, and adjust RF gain. For TX, enable "Remember power settings" and adjust power output to avoid ALC engagement. The key is avoiding any ALC indication whatsoever.

Try transmitting ("Tune" in WSJT-X) and monitor your radio's power and ALC (automatic level control) display. Adjust playback level in control panel to where transmit power reaches the target value and before the ALC starts attenuating the signal. Watch that ALC meter like a hawk!