CW Skimmer






October 8th, 2016 The software now supports CW Skimmer from Afreet Software inc. CW Skimmer simultaneously decodes all CW signals in the receiver passband - either 48, 96 or 192kHz. As well as CW Skimmer, the interface also supports MAP65 albeit in a basic mode (below).

Many thanks to Alex for the complimentary licence.

CW Skimmer interfaces with this software via:

  • A virtual serial cable, and
  • A virtual audio cable (although the soundcard Mixer input can be used if available).

Virtual Serial Cable

This provides a connection between the two programs which is used for frequency control - CW Skimmer reads the frequency from the console and changes the console frequency as you use the ↑↓ button in CW Skimmer.

Examples of virtual serial cable programs are:

Virtual Audio Cable

CW Skimmer reads the IQ data from the console over the virtual audio cable at a bandwidth of 48, 96 or 192 kHz (48kHz is recommended).  

Examples of virtual audio cables are:

Note: the interface uses a two-channel connection (I and Q), so the VAC settings must allow at least two channels (screenshot below). 


The 'baseband' data from the console starts at the low end of the displayed data. for example, in the screenshot below the displayed data starts at 3.5MHz, so the base frequency in the CW Skimmer display is also 3.5MHz. As CW Skimmer is configured to use SoftRock IF as the radio definition 3.5MHz corresponds to the LO frequemcy.


Click on either image for a full-size display.

In CW Skimmer click on a CW Decoder to send the  decoder's frequency to the active receiver on the console.



Virtual Serial Cable - Notes

Notes related to various products.


First create a connector, then a splitter.




Console Configuration

In the console program select More Options... in the View pane of the ribbon bar. Press the Select button to enable the options to be displayed. Make sure CW Skimmer is checked, then press OK. You will be prompted to restart the program. When restarted the CW Skimmer option is available.

Now press the CW Skimmer button to display the options.

The options are:

  • Enable - when selected [X] the Serial port and Output device are opened.
  • Serial port - one end of the virtual serial cable (more information below).
  • Diagnostics - when enabled all serial port traffic is sent to the system debugger, see Diagnostics below.
  • Bandwidth - the data (IQ) bandwdith sent over the virtual audio cable. The recommended bandwidth is 48kHz, make sure the virtual audio cable is configured to support the selected value.
  • Output device - the virtual audio cable (more information below).

Virtual Serial Cable

Here the Eltima Virtual Serial Port Driver is used.

The virtual serial cable has been created with the first port COM10, the second port COM11. COM10 will be used by the Console, COM11 by CW Skimmer.

Virtual Audio Cable

Here the software from Eugene Muzychenko is used.

The default settings are used which permit a bandwidth of 48kHz. The device name in Windows is Line 1 (Virtual Audio Cable).

Only use the cable definition for the data connection between the console and CW Skimmer, do not use it for other applications or to send audio from the console at the same.

Note: the interface uses a two-channel connection, so the VAC settings must allow at least two channels (screenshot below).

CW Skimmer Configuration

CW Skimmer is configured to use:

  • Radio type SoftRock-IF
  • Sample Rate 48kHz
  • Audio Signal I/O Device: the virtual audio cable
  • CAT TS-2000 with the virtual serial cable

In more detail

Start CW Skimmer, from the View menu select Settings.

  • Radio:
    • Select Hardware Type SoftRock-IF, sample rate 48kHz.
  • Audio: 
    • Signal I/O Device select the same virtual audio cable selected in the console,
    • (Optional) Audio I/O Device select the device for audio playback.
  • CAT:
    • Press Configure to display the OmniRig settings, Select Radio 1 TS-2000, Radio 2 None.


These settings have been found to work well. Note in Rig1 the Port is part of the virtual serial cable, explained in the Console configuration. You do not want Rig2 defined so select NONE from the RigType dropdown.



Now click the first button in the CW Skimmer toolbar - Start/Stop Radio. Two things should happen:

  1. A connection is made with the console via the serial cable, the console's lower frequency (left-hand side of the waterfall display) is shown in the CW Skimmer frequency windows, and
  2. The waterfall starts scrolling with CW signals.