Hello Guys - i built this from the Dave Lawton circuit rebuild from 2006. I did the scope test this morning. The unit was running on a 9 volt battery.
Question: is it possible to wire in a PLL, and Driver circuit to this one, or is it wiser to begin from scratch and build the entire thing integrated?
I added 2 photos i took after i recorded the signal digitally in Pro Tools. The high resolution reveals details.
The pulses are self evident, but the gate generates it's own frequency which appears below the line, out of phase or more accurately the opposite phase to the tone. I have no specific way of measuring these two frequencies (just learning the scope, eh), but they are variable, of course. My ear tells me the pulses are around 10kHz and the gate frequency is near 1 kHz. The 2 frequencies do seem to affect each other on the scope somewhat i.e. they appear to go in and out of phase through harmonic coupling as they are adjusted. Easy to record as well with a 100 ohm resistor on the +V line output from the PWM. I also loaded the circuit slightly with a headphone speaker in parallel.
This leads me to consider making a wav file, loading it in an iPod and driving a VIC with a stereo amplifier, with the track on loop. Output/voltage modulation via the volume control.
I realize this is somewhat off topic here, but these components i do have available so i think i'm going to pursue that idea for a while.
If these ideas contribute in any small way i'n grateful - i've learned and am learning a great deal here from everyone.
Thanks kindly - Bill