HP Cable Box 8591C manual + a on OFF

Spectrum Analyzer Mode Key Descriptions

Spectrum Analyzer Mode Functions

A-B + A ON OFF

A+C!

when ON is underlined, subtracts the data in trace B from the measured data in trace A. A minus sign (-) appears between the trace A status and the trace B status in the screen annotation while the function is active.

To deactivate this function, press A - B --+ A ON OFF so that OFF is underlined. The A-B + A and B-DL ---f B functions are math functions. Unlike operations on dBmV units, math functions operate on measurement units. Measurement units are used to format trace data for data within the graticule limits. The displayed amplitude of each element falls on one of 8000 vertical points with the value of 8000 being equal to the reference level. For log scale data, each point is equal to 0.01 dB. The peak

of a signal equal to 39 dBmV, or one division below the reference level, is equal to 7000 measurement units

(8000 - 1000 = 7000). In linear mode, each point has a resolution of [reference level in volts/SOOO].

For example, if trace A contains amplitude values of 39 dBmV and trace B contains amplitude values of 9 dBmV, the result of the A - B + A function would be 39.004 dBmV if dBmV units were used. Since measurement units are used for the A - B --+ A function, the result of A - B + A is

-1 dBmV (39 dBmV = 7000 measurement units, 9 dBmV = 4000 measurement units; the result is 3000 measurement units, which is equal to -1 dBmV).

Front-Panel Key Access @GEE-]

copies trace A into trace C.

Front-Panel Key Access @EXE]

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