I am using the RPi2-3 image on a Pi3 and the RB-USB-RIM.  I would like to set Channel B to output a PL tone of 110.9 Hz.  In SimpleUSB, I have set txmixb=tone.

I have set the level to 500.  Using an oscilloscope, I see no output from Channel B.  Where do I set the frequency and how do I enable it?

 

Tnx

Steve

N8AR