4. IF Amplitude Adjustments

The IF amplitude adjustments consist of the cal oscillator amplitude adjustment and the reference 15 dB attenuator adjustment.

Assembly Adjusted

A4 log amp/Cal oscillator

A5 IF assembly

Related Performance Tests

IF Gain Uncertainty

Scale Fidelity

Description

This adjustment sets the output amplitude of the A4 log amp/Cal oscillator and the absolute amplitude of the reference 15 dB attenuator.

The output of the A4 log amp/Cal oscillator is adjusted so that a -55 dBm signal applied to the 10.7 MHz IF input on the A5 IF assembly (A5J3) causes a displayed signal of -60 dBm. The effect of this adjustment is visible only after the ADJ CURR IF STATE sequence is complete. ADJ CURR IF STATE causes the IF gain adjustment to use the “new” output amplitude from the A4 log amp/Cal oscillator.

This procedure also sets the attenuator of the reference 15 dB attenuator so that a source amplitude change of 50 dB combined with a spectrum analyzer reference level change of 50 dB displays an amplitude difference of 50 dB.

 

TEST CABLE

 

 

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S P E C T R U M

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A N A L Y Z E R

 

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A5 IF BOARD

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SK16

Figure 2-7. IF Amplitude Adjustment Setup

2-26 Adjustment Procedures

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Image 66
Agilent Technologies 856290216 service manual If Amplitude Adjustments, Related Performance Tests