Re: Does alternating two frequencies create an intermediate
Well, kind of. If you look over a long time average, say in a frequency counter, then yes, it will look like a single frequency. And the longer the averaging time, the better it will look.
If you are looking at a very short interval, the instantaneous frequency will appear to hop, though. One thing you could do in the analog world is to lowpass or bandpass filter the composite signal. By eliminating the frequency harmonics, it will look more "sinusoidal".
Maybe a better way to do what you are trying to do is to take a single frequency and step through 4 discrete phase shifts. It is called serrodyne frequency translation.