rotax 582 facet electric fuel pump. noise is only there when the fuel pump is turned on. if it is off the noise is gone. I can keep the radio/intercom switch on and turn other switches off and it is isolated to the intercom for some reason. I bypassed the intercom and went straight to the handheld with no problems. The same power wire powers both the intercom and the radio charging station. I am only assuming but I feel there is enough power absorbtion going through the radio charger into the radio battery and finally out the radio to filter out the noise that way but for some reason it is pulsing through the intercom. I just tried putting an 1800uf capacitor on the radio power and it did not work. I am thinking I may put a higher capacitor on the fuel pump to see if that may do something. Any ideas on what capacitor?