What the variable duty waveform at the bottom of the drop down list in the waveform setup is for? It looks like a scalar wave using compression rather than frequency.

1. Please, take a look at this topic: 
https://www.spooky2.com/forums/viewtopic.php?p=36742#p36742

2. I didn't find any reference to the "Variable duty" waveform in this forum or in the current (20170808) Spooky User Guide.

So I looked a little deeper into the waveform itself. The waveform is a sequence of 31 square waves with duty cycles ranging from 3.1% to 96.9%

Using "Variable duty" waveform should provide an output very rich in harmonics. I would use only a WCM of 1 with this waveform since it has a built-in multiplier.

The waveform looks like this:

The duty cycles baked into the waveform are these:

It's definitely worth experimenting with for contact, remote and laser use. I would be reluctant to use it with Spooky Central unless John White expressly approves. The average duty cycle is 50%, so perhaps it is compatible.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=71&t=8752