HP 8924C Assembly page 458

Chapter 11, Block Diagrams
Section Details
458
Input Gain Control
The A4 High Power Attenuator reduces the level through the RF IN/OUT port by
4 dB (but does not affect the level into the ANTENNA IN port). Step attenuators
in the A5 Input section are switched in and out, manually or automatically. This
keeps the input level within an optimum range for the mixers, IF amplifiers, and
detectors.
Filters are automatically switched in to remove image and other interfering
signals. The frequency ranges of the filters are as follows:
• 150 MHz low-pass
• 150 MHz - 386 MHz bandpass
• 350 MHz - 650 MHz tuneable bandpass
• 600 MHz - 1000 MHz tunable bandpass
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