When I transmit on my 5000A I get low pitch feedback of my voice from the speakers as well as the screen showing the audio. I thought it was RF so I ferrite beaded everything and installed a ground rod and grounded my rig to it...all to no avail. I do not have the MON box lit in PowerSDR. I tried a hand mic and I use a Heil 781 and they both get the same results. What am I missing?