☞ In order to toggle USB or LSB mode in SSB mode you have to set the "BW" in channel filter cutoff control (8) to a positive (USB) or negative (LSB) value. The above screenshot shows a USB setup. See the (7) to (9) paragraphs below for details.
☞ The channel marker in the main spectrum display shows the actual band received taking in channel filtering into account.
Use the wheels to adjust the frequency shift in Hz from the center frequency of transmission. Left click on a digit sets the cursor position at this digit. Right click on a digit sets all digits on the right to zero. This effectively floors value at the digit position. Wheels are moved with the mousewheel while pointing at the wheel or by selecting the wheel with the left mouse click and using the keyboard arrows. Pressing shift simultaneously moves digit by 5 and pressing control moves it by 2.
Use this button to toggle between monaural and binaural mode. Monaural is classical single sideband or double sidebands modulation. In binaural mode I and Q samples are taken from the left and right stereo channels (or reversed).
When in monaural mode the icon shows a single loudspeaker and when in binaural mode it shows a pair of loudspeakers.
Effective only in binaural mode: reverses left and right audio channels so that the left is connected to Q and the right to the I complex signal channel.
Selects between SSB and DSB operation. When in SSB mode the icon shows a single sideband spectrum (USB side). When in DSB mode the icon shows a double sideband spectrum. In SSB mode the shape of the icon represents LSB or USB operation.
The transmitted signal in the sideband (SSB) or sidebands (DSB) sample rate of 48 kHz is further decimated by a power of two before being applied to the channel spectrum display and used to set the in channel filter limits. This effectively sets the total available bandwidth depending on the decimation:
- 1 (no decimation): 24 kHz (SSB) or 48 kHz (DSB)
- 2: 12 kHz (SSB) or 24 kHz (DSB)
- 4: 6 kHz (SSB) or 12 kHz (DSB)
- 8: 3 kHz (SSB) or 6 kHz (DSB)
- 16: 1.5 kHz (SSB) or 3 kHz (DSB)
The span value display is set as follows depending on the SSB or DSB mode:
- In SSB mode: the span goes from zero to the upper (USB: positive frequencies) or lower (LSB: negative frequencies) limit and the absolute value of the limit is displayed.
- In DSB mode: the span goes from the lower to the upper limit of same absolute value and ± the absolute value of the limit is displayed.
- In SSB mode this is the upper (USB: positive frequencies) or lower (LSB: negative frequencies) cutoff of the in channel single side band bandpass filter. The value triggers LSB mode when negative and USB when positive
- In SSB mode this is the lower cutoff (USB: positive frequencies) or higher cutoff (LSB: negative frequencies) of the in channel single side band bandpass filter.
This is the volume of the audio signal from 0.0 (mute) to 2.0 (maximum). It can be varied continuously in 0.1 steps using the dial button. The Loudspeaker button is the audio mute toggle.
Sets the CW speed in Words Per Minute (WPM). This is based on the word "PARIS" sent 5 times. For 5 WPM the dot length is 240 ms. In other terms the dot length is calculated as 1.2 / WPM seconds. The dot length is used as the base to compute other timings:
- Element (dot or dash) silence separator: 1 dot length
Opens a file dialog to select the audio file to be played. It must be 48 kHz F32LE raw format. If binaural mode is selected it takes a 2 channel (stereo) file else it should be mono.
Using sox a .wav file can be converted with this command: `sox piano.wav -t raw -r 48k -c 1 -b 32 -L -e float piano.raw` (mono) or `sox piano.wav -t raw -r 48k -c 2 -b 32 -L -e float piano.raw` (stereo)
