Keysight Technologies N5247B, Service Manual

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3-46 Keysight N5247B Service Guide
Tests and Adjustments
Performance Tests
3-
5. The noise source is turned on and a hot noise response is measured, Phot.
6. The noise source is turned off and a cold noise response is measured,
Pcold.
7. The receiver noise figure for each point is calculated from:
8. This test is repeated for 2, 4, 8, and 24 MHz noise IF bandwidths.
If the Analyzer Fails this Test:
A failure of this test indicates a fault in the noise receiver chain. This can
indicate a faulty assembly or a loose cable.
— Check for proper torquing of all semi-rigid cables in the receiver chain, and
then repeat this test.
— If the analyzer still fails this test, replace the A7 Noise Receiver board and
repeat this test. Refer to “Removing and Replacing the A4–A17 Boards” on
page 7-18 .
Noise State Calibration Coefficients
Noise Jitter Test
Function of the Test: To measure the stability of a signal in the internal noise
receiver system.
Specification Tested: Test Port Input: Option 029 – Noise Jitter
Equipment Used: Load standard
Description of the Test:
Noise jitter is a calculation of the standard deviation of a 201 point CW
measurement using the noise receiver. In a healthy analyzer, this measurement
is only affected by the sampling error of the analog to digital converter on the
noise receiver board.
1. The analyzer is Preset.
2. The analyzer is set to make a noise power density measurement with the
noise gain set to 0 dB and the noise bandwidth set to 4 MHz. The analyzer
is set up for a 201 point CW transmission measurement using the noise
receiver.
IMPORTANT!
For the most current information on the Table 7-2 “Verification,
Performance, and Other Tests and Procedures” column’s content, refer to
https://cal.software.keysight.com/PNA/Help/N7840AWebHelp.htm .