Since the inverse peak voltage rating of the high-frequency crystal rectifiers is only a few volts, the range of the voltmeter can be extended only slightly by reducing the sensitivity of the d-c amplifier. Voltages above one volt are measured by the use of capacitance voltage dividers placed ahead of the probe. Two of these multipliers are furnished to give a complete coverage to 100 volts in decade steps.
In addition to the multipliers, fittings are provided for two coaxial connectors of the General Radio 774 type. A 50-ohm disc-type resistor is also provided. These are illustrated in Figure 5. The 50-ohm resistor can be used in conjunction with the voltmeter for making approximate measurements of power up to 1000 Mc.
Figure 4. Elementary schematic circuit diagram of the complete voltmeter.
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