FSK BIT Analyzer (PRO Only)

 

General description

The FSK BIT Analyzer (FBA) is a tool used for analyzing the FSK bit length. It provides a decoder part similar to the other SkySweeper FSK based decoders and the bit length display as well as the text window for printing the analysis results out in text format.

 

The FBA decoder searches the transmission within the given frequency boundaries. Also you can set the lower FSK frequency by double clicking the mouse on the required frequency position, and then SkySweeper allows you to set a second (=higher) frequency by a mouse click. The values of frequencies and the frequency offset are shown also on the screen.

 

When a transmission has been detected within the given range, the decoder will then lock itself to that frequency. When locked, the decoder draws a bold blue line on the spectrum display at the currently locked frequency. If the decoder is not locked, then the blue line is not shown as bold.

 

In the non-locked state, the carrier frequencies are automatically monitored within the given frequency boundaries. If the carrier frequency changes, then the decoder moves to a new frequency. If 'Lock' is pressed in the user interface, then the decoder will not automatically change its frequency. ‘Reset’ resets the decoder and the results can be saved by using ‘Save’. The parameters can be modified by pressing the ‘Config’ button.

 

The received text can be saved with ‘Save’. ‘Reset’ resets the decoder and ‘Config’ is used to set the parameters.

 

SkySweeper supports both FFT and waterfall display modes for decoder tuning. The Decoder Spectrum Dialog chapter gives more information about the spectrum display options.

 

Configuration

Pressing the ‘Config’ button opens the following Configuration dialog box.

 

 

 

 

Parameters

 

Tone Scan Area

The FSK transmission has two tones - Mark and Space. The scanned frequency range for Mark and Space will be given with two values, namely ‘low’ and ‘high’. The Mark and Space tones are searched for only inside this frequency window.

 

Fixed Offset

If the Fixed Offset check box is selected, the user can enter the fixed frequency offset between the Mark and Space carrier frequencies. The fixed frequency offset is used in automatic scanning mode.

 

Line length

Line length in milliseconds.

Number of lines

Number of lines in display

Line Start Offset

This value shows how much the signal is delayed, in milliseconds, before printing starts from the zero position.

 

Line width

Line width in pixels.

Line space

Number of pixels between lines

 

AVG Filter Length

This is the Average Filter Length in milliseconds. If the baud rate is low, the longer average filter gives better analyzing performance.

 

Print statistics into text window

If this switch is selected, the analyzed results (bit lengths) will be printed into the text window.

Time stamp

If this switch is selected, the time stamp is added to the text. This works only if ‘Print statistics into text window’ is selected.

Bit 0 color

Defines a color used in ‘0’ bit printing.

 

Bit 1 color

Defines a color used in ‘1’ bit printing.

Space color

Defines a color, which is used to separate lines.