i just finished modifying the hobbyzone sonic combat module to put it on a regular plane and it was a pain in the behind. here is what a friend of mine and i have come up with.

the module has four wires coming out of it. the first wire (with the black stripe) is the negative. the one next to the negative is the signal wire. the third one does nothing. the fourth one is the positive. i started by soldering the positive and negative to a plug for a battery. then soldered the positive wire also to a momentary switch that i got from radio shack. then the signal wire is soldered to the other side of the switch. i epoxied the switch to the top of a servo so i could use my gear channel on my radio to push the button. it works really good but does add some weight to the aircraft. the sound it makes when it fires reminds me of a machine gun and the high pitch squeel it makes when it registers a hit is deafening. we use a wattage f-22 raptor and a wattage mirage 2000-5 to engage in some good 'ol america versus france fighting. the raptor has an mpi cobalt 400 13t with ten cells and the mirage uses a speed 400 on eight cells. both have carbon reinforced 5x5 zagi props. remarkably enough the plans are evenly matched. sonic combat without having to program little computer chips is definately the way to go.