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Overview

14

Keysight 537A Operating Note

Measurement

A detector and indicator are required to indicate the dip in coaxial line power at resonance. It is 

recommended that 10 dB of attenuation be placed between the signal source and the frequency 

meter. If insufficient power is available to use a 10 dB attenuator, an attenuator offering less 

attenuation may be used, to a minimum of 3 dB. The attenuator prevents a shift in the frequency of 

the signal source due to line impedance changes at resonance.
The detector-indicator combination can be a thermistor mount and power meter such as the 

Keysight 478A and 432A, or a crystal detector and SWR meter. If a SWR meter is used as the 

indicator, the signal source must be modulated at 1000 Hz (sine or square wave modulation). For 

visual display, an oscilloscope can be used as the indicator. When using an oscilloscope for swept 

frequency displays, be sure to sweep the oscilloscope at the same rate as the signal source. 

Resonance will be noted as a dip in the oscilloscope pattern

Figure 1

Type-N connector dimensions

Connectors

The input and output connectors are type-N, female and are compatible with connectors whose 

dimensions conform to MIL-C-39012.
N-female Pin Depth: 0.207 to 0.201 in (effective 0 to –0.006)

CAUTION

Do NOT run dial into stops at either end of dial

If frequency measurement is one part of the measurement procedure, be sure to move meter 

off resonance before proceeding with other measurements.

Содержание 537A

Страница 1: ...Keysight 537A Coaxial Frequency Meter Operating Note...

Страница 2: ...customarily provided to the public to use modify reproduce release perform dis play or disclose commercial computer soft ware or commercial computer software documentation No additional government req...

Страница 3: ...ollowing symbols on the instrument and in the documentation indicate precautions which must be taken to maintain safe operation of the instrument When you see this symbol on your instrument you should...

Страница 4: ...er source to the product input wiring terminals power cord or supplied power cord set Whenever it is likely that the protection has been impaired the product must be made inoperative and secured again...

Страница 5: ...Control Instrument product The affixed product label is as shown below Do not dispose in domestic household waste To return this unwanted instrument contact your nearest Keysight Service Center or vis...

Страница 6: ...6 Keysight 537A Operating Note THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK...

Страница 7: ...nd Electronic Equipment WEEE Directive 5 Product category 5 Sales and Technical Support 5 List of Figures 9 List of Tables 11 Overview 13 Description 13 Specifications 13 Measurement 14 Performance Te...

Страница 8: ...8 Keysight 537A Operating Note THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK...

Страница 9: ...Keysight 537A Operating Note 9 List of Figures Figure 1 Type N connector dimensions 14 Figure 2 Return loss test setup 16 Figure 3 Overall accuracy test setup 19...

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Страница 11: ...Keysight 537A Operating Note 11 List of Tables Table 1 Specifications 13 Table 2 Recommended test equipment 15 Table 3 Equipment 16 Table 4 Return loss limits 18 Table 5 Test instruments 19...

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Страница 13: ...lead screw which is spring loaded to prevent backlash is used to position the piston in the cavity Due to the design of the cavity its electrical length is extended at lower frequencies and there are...

Страница 14: ...tector and SWR meter If a SWR meter is used as the indicator the signal source must be modulated at 1000 Hz sine or square wave modulation For visual display an oscilloscope can be used as the indicat...

Страница 15: ...given Table 2 Recommended test equipment Maintenance For dial stop gear replacement instrument recalibration or any other repair needs contact your local Keysight Technologies Sales and Service office...

Страница 16: ...tometer test setup The reflectometer is calibrated using a short The 537A coaxial frequency meter under test is connected and the return measured Figure 2 Return loss test setup Table 3 Equipment Inst...

Страница 17: ...12 Increase the dB DIV resolution by steps to 0 25 dB DIV if necessary adjust the OFFSET CAL control to return the trace to the center graticule 13 Disconnect the short from the reflectometer test po...

Страница 18: ...reater than the following limits Table 4 Return loss limits 18 If the above limits are not met test the 537A using a slotted line at the frequency in question Lower limit of reading Coupler directivit...

Страница 19: ...ted to the center of the absorption notch of the 537A The frequency of the sweep oscillator is measured with a counter and compared with the specifications in Table 1 The sweep oscillator is set to au...

Страница 20: ...enter it on the display by adjusting the sweep limits on the sweep oscillator 6 Set the sweep oscillator to CW and adjust the frequency to the center of the notch lowest indication on the oscilloscope...

Страница 21: ...uency end setting 12 4 GHz is set almost one half turn about 150 degrees counterclockwise from the stop The dial 5 is held to the dial holder 10 by two set screws 9 Check frequency accuracy at 12 4 GH...

Страница 22: ...Calibration Procedure 22 Keysight 537A Operating Note THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK...

Страница 23: ...is subject to change without notice Always refer to the Keysight website for the latest revision Keysight Technologies 2014 2018 Edition 2 November 13 2018 Printed in Malaysia 00536 90013 00536 90013...

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