I'm playing around with a toroidal coil and eventually want to use it for some wireless power transfer experiments. My problem is that i need a function generator that can output around 1-5 mhz, and they are kinda pricey. I'm not going to need to know the precise frequency I'm producing, just to be able to sweep it through a range untill I hit resonance. Anyone have any suggestions? I'm really looking for an option under $50, because if I go much over that I might as well spend the money on a used unit off eBay. Thanks in advance!