There was also, if memory serves me correctly, a line of Zenith color sets that had sound systems the company called "SEq". These were used in Zenith's higher-end color TVs and may have even been used in the firm's first projection sets.
BTW, I have a Zenith "Sentry 2" 19-inch color TV, now 18 years old and still working like new. (It should, as I only actively used it for four years in the mid-late 1990s until I moved and replaced it with an RCA CTC185, which I still have as well.) The only problem with it, if you want to call it a problem, is the gray paint on the cabinet is flaking off in spots, revealing the black cabinet beneath. The Sentry 2 sets were one step below System 3 and were, again if I remember correctly, some of the last sets made by Zenith of Chicago to use the original Zenith lightning-bolt logo as the first letter of the name "Zenith"; the name appeared just above the remote sensor on the vertical control panel to the right of the CRT, looking at the set from the front.
I also owned two Zenith 13" color portables, one of which was part of Zenith's "Custom Series" of portable televisions in the 1980s. My "Custom Series" set had one-knob varactor electronic tuning, as well as a faux woodgrain plastic cabinet and front panel; I purchased it in 1982. The other, my first new Zenith color set which I purchased new in 1979, was their model L1310C. This set was in a rather nondescript black cabinet, with silver color trim around the edge of the top of the set. I left both of these sets at my former home when I moved to an apartment 13 years ago; I have no idea what happened to them after I left the old house for the last time. The TVs were still working like new at this time, so if they were unceremoniously junked after I left town it would have been a shame; however, I wasn't even around when the house was being prepared for sale (long story and OT), so I have absolutely no clue what actually happened to the sets. For all I know they may well have been junked and sent to a landfill.
