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Figure 1-41—3:1 Lissajous patterns and calculation of frequency ratio.
THE OCTOPUS.—The octopus is a small, homemade test set used with an oscilloscope to check
electronic components in circuit. It can be made easily and cheaply using parts from the supply system.
Figure 1-42 is a schematic of an octopus that uses either a 6.3-volt filament transformer or an audio
oscillator for input power. The benefits of in circuit troubleshooting with an octopus are (1) reduced
maintenance time, (2) less chance of damage from soldering-iron heat, and (3) a visual display of the
component's condition.
