Generator Noise
Bit of a 'chicken and egg' situation- of course it could be the generator, but it could alco be the intercom.
Firstly check all your earths/bonding etc. This is on all systems not just Radio and power generation, as well as aircraft structure.
I can only speculate on the intercom set-up but if you haven't lost an earth there, it may be just be a faulty intercom box or some screening failed somewhere.
Or why not just pay someone to come and sort it for you?! Good luck...