I think the cheapest and easiest way for pulse width modulation or signal generation is just shelling out 150 dollars for a decent lab grade unit. If I had known this before I bought the Lawton circuit for the same price, I would have gone with a nice one with tons of options and an LED readout. I found one on eBay for 130 not too long ago. The Lawton circuit works great too, I just like the extra bells and whistles. Unless your replicating, how the signal is generated is really not an issue.