Lot of 4 Vintage Zenith Tech Topics Publication: February 1968 "Zenith Outdoor Antennas". 4 pages Paper; March 1968 "High Voltage and Focus Tracking" 4 pages Paper; April 1968: "High Voltage Measurement Indicator" 4 pages Paper; and, May 1968 "HV Regulation (6HS5) 4 Pages Paper. All measure 8-1/2 inches x 11 inches.
Very good condition. Crease across center from being folded in half.