I brought it to the lab to check it out, and I was shocked by the intense level of severe RFI it generated, terminated or unterminated. The interference this device produces would have interfered with all of my ham radio equipment from 160 through 2 meters, according to the measurements I quickly made here using an HF receiver and an ICOM R7000, shown on the right. I have not measured the total radiation levels, but believe they are unacceptable.
We are always on the lookout for RFI, as it tends to get into audio recordings and can be very problematic, so when such a gadget is found, it sets of alarms. In my opinion, this device falls under the category of an "incidental radiator" and its use is prohibited by the FCC when it produces harmful interference to a licensed service, which it does. Fair warning! This polluter of the airwaves is going back.
The Sears 2871219 should, in my opinion, be labeled with an FCC type 15 warning at the very least. These warnings read:
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
Of course, that would be for devices that were properly checked and tested. I don't believe this ever has been, nor do I think it would comply with the rules had it been properly tested. The bare circuit board is in an unshielded plastic case with no bypassing or other measures to reduce interference. People are going to leave this device plugged in for extended periods of time in their homes and garages; it produces considerable current and has no visible fuse, and I think is built more like a toy than a proper shop tool. As an "Unintentional Emitter" aka Incidental Emitter, Sears can claim that devices such as light bulbs, battery chargers etc. are exempt from the FCC rules, leaving it to the consumer to find out on his own, and be subjected to the consequences. Still, the FCC is clear on the labeling of devices, and the rules governing interference from consumer electronics. See this for further information.