Armorwerx U94 PTT System Compatible with Yaesu Radio (Military/NATO-US Wired)

In hindsight I should've bought the $10 version of this on EBay instead of this one. I get lot's of hum from my expensive ham radio & expensive headset (I say that to suggest they aren't the problem). All in all this feels like decent quality but I just can't get past the hum in the background.