this definitely helps, i simply failed to realise the function of the circuit. i do know a thing or two about fourier theory, but it's good that you explained all this for the greater good. i agree 100% percent with you on the 'test before you install' mentality, i've had problems in the past too.
i do have an idea, though, about creating harmonics. i don't know if you are familiar with PLL's (phase locked loops), but one way of creating a tunable output is using one such circuit. a good thing with this type of circuit is that it has a feedback loop and allows for the incoming signal to be locked and therefore sustain that specific frequency. the only downside with this is that a proper good quality design costs a bit. a cheaper design can be made but i cannot guarantee the results will be respectable. now if someone simply wants harmonics of higher order, then a simple frequency divider can be used to emulate this. i know it's nowhere near what it really is, or what it should be for that matter, but i'm sure i could get something interesting out of this. i'll give it a try this summer and post with any respectable results. as for the PLL, this needs alot more work and design so, unless someone's already done this, i'll be trying out some designs see where it takes me. give me some feedback on what you think of this, i'd greatly appreciate it.
the lead reversal/phase switch method is not bad, yet it only gives a mixed output. with a PLL this can be fixed, giving true harmonic output, and in conjunction with the phase switch method you get a full sustainer kit. be prepared, though, coz PLL's aren't easy to build.
cheers, mojoDodo