You will need to open the unit and make sure a 9 volt battery is connected.
First thing you do is to connect the alligator clip to some part of exposed chassis, or a ground connection if available. I usually loosen a screw attached to the chassis if its available and clip it to that exposed head. Sometimes I take the cover off and attach to the metal chassis. With the clip secured you need to turn on the unit (top button) ... then while it stays on for a few seconds, push the memory button below. Then, you will need to quickly reverse the power cord going into the socket. Within three seconds push the memory button again. A light will indicate which position was the correct in the socket. If you have a three prong IEC cord? You will need to get a cheap one and cut off the ground plug so you can flip the cord. If you find the polarity is reversed, it will require someone who knows how, to reconnect the power wires inside the unit. Warning: Its not safe to use an IEC plug minus the ground plug, so don’t just flip it and leave it that way. If your system is high end what you hear will make a difference. I have one component that came with a wall wart and found it needed to be placed upside down (tail side up) to be correct. It sounds better with the the correct orientation. I found only one piece of equipment that was wired IEC to be reversed. The other manufacturers were diligent to get it right.
what the heck is a Namiki DF-100 Direction Finder
I was at salvation army (which is a sometime bountiful hunting ground for ancient audio) and I found a Namiki DF-100 Direction Finder. It's a small, blue metal box about 5 x 2 inches. On the back is Japanese writing and an a diagram of an amp and cord. There are two buttons on the front and 4 indicator lights. Anyone have any idea what this thing is? How to work it? Thanks tons