Audio; Bandwidth; Center; Cwfilter - SCS PTC-IIIusb User Manual

The Audio-denoiser-menu (aud:-menu) is activated with the command AUdio. The
command prompt takes the form aud: .
The following commands are available in the aud:-menu:
Bandwith, Center, CWfilter, DD, Delay, Help, Invert, Notch,
Peak, Quit, Through, TOne.
All other (normal) commands are not available in the aud:-menu! Quit or DD exit the
aud:-menu.
The commands of the aud:-menu in detail:
7.1

Bandwidth

Default setting: 300
Parameter: X 30... 1000, Bandwith in Hz.
Adjusts the -6 dB bandwidth of the CW-filter continuously between 30 and 1000 Hz.
(Refer also to command CWfilter, chapter 7.3).
7.2

Center

Default setting: 1400
Parameter: X 300... 2700, center frequency of the CW-filter.
Sets the center frequency of the CW-filter continuously between 300 and 2700 Hz. (Refer
also to command CWfilter, chapter
The Center command also adjusts the audio frequency of the CW-Terminal (chapter
6.30) of the PTC-IIIusb send and receive sides. (In firmware releases prior to version
1.12, the CW-Terminal used the current Mark-frequency, which sometimes was not
particularly suitable).
7.3

CWfilter

Activates the CW-filter, using the center frequency set by the Center command, and the
bandwidth set by the Bandwidth command.
The filter is designed as FIR with a linear phase-change, so that even with a bandwidth of
30 Hz it does not ring. The transfer function has not been designed for maximum edge
steepness, but a shape delivering a signal easily readable for the human ear, and the best
signal/noise ratio possible.

7 Audio

7.3 and the command CWTerm, chapter 6.30).
Chapter 7
7 Audio
97