Been fooling with this miniature sweep/signal generator offered on EBay that covers 35 - 4400 mHz. Runs off 5V supply and supplies a sine wave (looks pretty clean). Has a touch screen and you can set the sweep time and sweep increments. Want to see if it is useful for checking filters in radios. I has two outputs if you have a dual o'scope. Power output is adjustable. There are many different versions of this product on EBay but I liked this one the best. No instructions though, you're on your own.