Federal Signal310-MV Audio Master Industrial Two Way Intercom, Multi-Voltage, Gray

Bought this to replace an older Atkinson Dynamic unit after talking to the technicians at Federal Signal.Right off the bat - we had some issues.1. Terrible 60 cycle hum - when first powered on until you use the device, it hums SO BADLY it is irritating. The older AD units did NOT do this.2. NO WIRING HARNESS - you have to provide power to this unit and wire it in yourself, using their crappy manual.3. No wiring scheme for backwards usage on older units - despite their technician telling me that they can be used with older AD units - the wiring scheme is NOT in their manual4. Poor support - after calling two days in a row, they are clueless as to how to properly wire one of these up, and their technician even complained that i bought one of these, because "they really don't support these anymore, and nobody knows much on these units at Federal Signal any more".Not enthused so far. Maybe if i get some actual help from the manufacturer i would be more enthused. I will say, at nearly half the cost of the now discontinued but VERY reliable AD unit, i am guessing i got what i paid for. A 20 pound boat anchor.