My understanding was that the cable companies sent back their old STAR units rebuilt when hardware modifications were necessary (thus becoming a STAR II or III). So, some of the units could of dated back to the beginning (1982).
From "The Improbable Rise of a Media Phenomenon"
"We discovered that our first WeatherSTARs were radiating energy in a way that interfered with the antenna's reception of Channel 2, we developed a way to eliminate the radiation leakage. And thus was invented STAR 2. Then, in 1985, the FCC decided to reduce the spacing between geosynchronous satellites to make room for more satellites. I'll skip the technical aspects of what this entailed for us - suffice it to say they were complicated. We enlisted the help of Wegener Communications in Atlanta and, at the cost of about $2 million, we figured out how to adjust the STAR so that it transmitted out localized weather data differently. And thus was invented STAR 3."
About the Channel 2 interference:
"After much investivation, Galumbeck and his colleagues discovered that although the WeatherSTAR conformed to FCC radiation standards in terms of what was escaping from the unit, the STAR was nevertheless energetically radiating outward through its sensors and wreaking havoc on Channel 2's VHF frequency. The Weather Channel engineers scrambled to seal up the STARs more effectively. THey also added a "doughnut" of ferrite beads - which helped absorb very high frequencies - to all the leads going into and out of the STARs."
