I still have a Lowrance Fish Lo-K-Tor a.k.a. the "little green box" shown in the picture. Still in working condition. Rigged it to connect to a storage battery as well as two lantern batteries and used it up into the '90s. Wife gave it to me for Christmas back around 1979-1980.
What ever happened to Carl Malz after Fishing Facts? I always enjoyed his articles. I remember that picture. That was the time frame that I started spoonplugging. Bill Beck.