Ribbon Bar

You select the number of receivers and visibility of the DSP options (see below) from the ribbon bar.


DSP Options

From the top down, the DSP options are:

Frequency: The current receiver index and the filter width are shown in yellow. To change the frequency position the mouse pointer over a digital and rotate the mouse wheel (you can also click in the main waterfall windows).

Playback: Select the playback device from the dropdown list. The audio level is adjusted with the slider, to mute press the button.

Mode: Select the demodulation mode, to change the available modes click the ellipses button.

Filter:  Select the filter width, to change the available widths click the ellipses button.

AGC: The standard options - Fast, Medium, Slow, each individually customisable.

CW: A single node peak filter optimised  for CW.

Noise Blanker: removes clicks and pops.

Noise Reduction: A variety of algorithms for combatting unwanted interference.

Notch: A powerful automatic notch filter which can remove at least six simultaneous carriers.

Squelch: For FM only.


Auto Mute

The auto mute feature automatically blanks the waterfall and mutes the audio when a strong signal is detected. This is a very useful option to have in a SDR console, apart from anything else it ensures no audio feedback if you are listening to your transmission frequency. Auto-mute is a simple approach to handling strong signal overload situations. More...

Filter Definitions

The main pre-demodulation filtering uses Finite Impulse response (FIR) filters. You can design your own filters - not just the bandwidth but the response.

Click the ellipses button (top left) in the Filter pane, the Filter Definitions for the current mode are listed. In this window you define the preset filters with an advanced Filter window.(below).

Filter Definition

In this example a standard SSB bandpass filter is defined with a passband from 100Hz to 2,900Hz. The shape factor (frequency response) depends on the number of taps - as you increase the taps the response becomes sharper however the trade-off is more latency and ringing (unwanted oscillation).

The windowing also affects the filter response, more information.