Tektronix TDS744A Color Digital Oscilloscope 4CH Tuning Verified 500MHz to Used
Tektronix ・ TDS744A. Tektronix TDS744A 4CH Digital Oscilloscope. There is a faint circle on the lower right corner of the screen that looks like an LCD irregularity, but it is located in a position that does not affect the waveforms or text.