4 test frequencies, compatible with both analog and digital oscilloscopes when connected. Supports dual signal input with alternating display. Features 4 selectable frequency settings with adjustable alternating speed. One-button toggle between single-channel and alternating display. HOW TO USE: Oscilloscope setup: Set the oscilloscope to X-Y mode (method varies by model—consult your device manual). Adjust vertical sensitivity of both X and Y channels to 1 V/div; for single-channel oscilloscopes, adjust only one channel. For analog oscilloscopes: No timebase adjustment required. For digital oscilloscopes: Set timebase between 1–5 ms. After correct connection, a horizontal line should appear on screen. If a vertical line appears, reverse the X and Y probe connections. Adjust vertical and horizontal sensitivity until both lines are fully visible within the display area. Connecting to an analog oscilloscope: Set the oscilloscope to X-Y mode (via button or knob—refer to your oscilloscope’s user guide). Connect the BNC cable and power on. A horizontal line should appear. Adjust X and Y vertical sensitivity to ~1 V/div, then fine-tune X and Y attenuation so the line fits within the display. The X-axis attenuation potentiometer (top side) can be used to adjust horizontal line length. When the test probe is shorted, a vertical line should appear. If too long or too short, adjust Y-channel sensitivity until the line fits within the display area.