Figure 2.2, Schematic of X ten Probe. There are two parts to this figure. Part eh shows a stylized drawing of a probe on the left and a stylized drawing of a BNC coaxial connector on the right. The two are connected by a standard schematic representation of coaxial cable which is two parallel solid lines with a dashed line between the two lines and also parallel. The two solid lines represent the shield, outer conductor. The dashed line represents the center conductor. On the left the probe is shown as containing a 9 meg ohm resistor with one end connected to the probe tip and the other connected to the center conductor of the coaxial cable. A variable capacitor is shown connected in parallel with the 9 meg resistor. Part B is a totally schematic diagram of the probe. On the left there are two connection points. They are labeled from circuit under test. On the right are two more connection points labeled to oscilloscope electronics. The lower left connection point is connected to the lower right connection point. The upper left connection point is connected to one end of R one, a 9 meg ohm resistor. A variable capacitor, C1, is connected in parallel with R1. The other end of R1 connects to one end of a fixed capacitor which is labeled C2, 150 p f. The other end of this capacitor connects to the line that connects between the two lower connection points. Connected in parallel with C2 is a resistor R2, one meg ohm. R1 and C1 are in the probe tip. C2 is made up of the cable capacitance plus the input capacitance of the scope. R1 is inside the scope and is its input resistance. This completes the verbal description.
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