// Status=review .Receiver Noise Level - If it is not already highlighted in green, click the *Monitor* button to start normal receive operation. - Be sure your transceiver is set to *USB* (or *USB Data*) mode. - Use the receiver gain controls and/or the computer's audio mixer controls to set the background noise level (scale at lower left of main window) to around 30 dB when no signals are present. It is usually best to turn AGC off or reduce the RF gain control to minimize AGC action. + TIP: The PC audio mixer normally has two sliders, one for each application attached which should be set to maximum (0dB FS) as it cannot help with distortion from overly high or low input levels from your receiver and another *Master* level which is analogue attenuator on the sound card before the Analogue to Digital Converter (ADC). The *Master* level can be used to adjust the signal level received by _WSJT-X_. .Bandwidth and Frequency Setting - If your transceiver offers more than one bandwidth setting in USB mode, it may be advantageous to choose the widest one possible, up to about 5 kHz. - If you have only a standard SSB filter you won’t be able to display more than about 2.7 kHz bandwidth. Depending on the exact dial frequency setting, on HF bands you can display the full sub-band generally used for one mode. .Transmitter Audio Level * Click the *Tune* button on the main screen to switch the radio into transmit mode and generate a steady audio tone. * Listen to the generated audio tone using your radio’s *Monitor* facility. The transmitted tone should be perfectly smooth, with no clicks or glitches. Make sure that this is true even when you simultaneously use the computer to do other tasks such as email, web browsing, etc.. * Adjust the *Pwr* slider (at right edge of main window) downward from its maximum until the RF output from your transmitter falls slightly. This is generally a good level for audio drive. * Toggle the *Tune* button once more or click *Halt Tx* to stop your test transmission.