A couple of comments:
You said "I recorded the audio through the node and it is crystal clear."? I assume this is a file of the audio being sent to your HT created by turning on the recording capability as suggested previously.??
You also said, "Starting this morning after the node connected and announced ip address the hum was so bad the radio was still receiving after the shari stopped transmitting."? But if the node has stopped transmitting and your HT is still receiving then the noise is probably coming from something else, is always there and you must not be using PL.
Please confirm and elaborate a bit on this.
Steve-N8AR