WinWarbler Soundcard PSK Broadband Decode Settings

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The PSK Broadband Decode tab of WinWarbler's Configuration window provides control over a mechanism that can simultaneously decode and monitor up to 47 signals whose audio tones fall in the range of 100 Hz. to 3500 Hz.  (screen capture)

When the enable box is checked, WinWarbler deploys 47 monitor channels across the audio band from 100 hertz to 3500 hertz; each monitor channel thus covers approximately 72 hertz of spectrum. Signals that meet the decoding criteria specified below can be optionally denoted by channel markers: triangles on a black bar or white bar above the tuning display as specified by the Optimize tuning display panel setting. Channel markers appear if the Channel Monitor is enabled or if the Channel Monitor's always show monitor channel markers box is checked. Decoded callsigns are displayed in the Stations Heard window.

When the Channel Monitor panel's enable box is checked, WinWarbler displays a Channel Monitor window that displays the following information for each monitor channel:

• frequency

• signal quality

• signal strength

• receiving_callsign

• transmitting_callsign

• decoded text (this text either scrolls left to right or is painted right to left as specified by the decoded text panel setting)

The AFC control  specifies the maximum track-able excursion from a PSK signal's center frequency in hertz for each monitor channel. 0 disables AFC; the maximum value is 1000 hertz. Half the monitor channel range -- 36 hertz -- is a good starting value for this setting.

The Squelch panel provides controls that set the squelch level and speed for all monitor channels. If an incoming signal's quality is below that of the specified squelch level, characters are not decoded. The minimum value 0 disables all squelch action, whereas the maximum value of 99 disables all decoding. A squelch level of 25 with fast action is a reasonable initial setting.

The Decoding Triggers panel provides settings that determine whether a monitored channel is considered to be tracking a viable PSK signal. WinWarbler checks each monitor channel's signal quality every 200 ms and assigns it a state. Initially, each monitor channel's state is unlocked. If a monitor channel's signal quality exceeds the squelch level, a counter is incremented, and that monitor channel is considered to be locking; if the signal quality falls below the squelch level, the counter is zeroed, and the monitor channel is considered to be unlocked. If the counter reaches the value specified in the Start setting, the monitor channel is considered locked, which enables the subsequent extraction of callsign information from the decoded text. WinWarbler continues to sample a locked monitor channel's signal quality every 200 ms. If the signal quality falls below the squelch level, a counter is incremented and the monitor channels is considered to be unlocking. If the signal quality subsequently exceeds the squelch level, the counter is zeroed and the channel is again considered locked. If the counter reaches the value specified in the Stop setting, the monitor channel is considered unlocked, and callsign extraction is discontinued. Each monitor channel is managed individually through the four states: unlocked, locking, locked, and unlocking. The state of each monitor channel is indicated by the color of the font used to render its channel number in the Channel Monitor window:

The QSO Inactivity Timeout determines how long a monitor channel can remain unlocked before its captured callsign information is discarded. Since WinWarbler may only be monitoring one side of a QSO, 2 minutes is a reasonable value for this setting.

The Stations Heard panel provides setting that govern the list of transmitting stations displayed in the Stations Heard window:

The decoded text panel determines whether decoded displayed in Channel Monitor entries and Stations Heard entries scrolls continuously from left to right, or is painted right to left.