I have a Galaxy 959 CB radio. I want to ad a galaxy echo box to the set up, but when I hook the echo box up to the radio, it causes a buzzing sound in the transmission and I cannot be heard. the radio works great, but if I hook up the echo box this problem presents itself. I have both the radio and the echo box hooked to the same power wire, is this the problem? does this cause a feedback to set up? I had the whole rig in the shop twice, and they say it works great on the table? this is driving me nuts, so any help or Idea would be helpful, thank you, victor