Chapter 2 — Spectrum Analyzer Verification 2-9 Displayed Average Noise Level (DANL)
MS272xC MM PN: 10580-00279 Rev. E 2-21
2-9 Displayed Average Noise Level (DANL)
The following test is used to verify the Displayed Average Noise Level (DANL) of the spectrum analyzer
systems in the MS272xC Spectrum Master.
Equipment Required for MS2722C, MS2723C, and MS2724C
• Anritsu 28N50-2 50 ohm Termination
Equipment Required for MS2725C and MS2726C
• Anritsu 28KF50 50 ohm Termination
Preamp On Procedure
1. Connect the 28N50-2 or 28KF50-2 50 ohm termination to the MS272xC Spectrum Analyzer RF In.
2. Set the MS272xC to Spectrum Analyzer mode and then preset the instrument. Press the Shift key, the
Sweep (3) key, Sweep Mode submenu key and then the Performance submenu key.
3. Press the Amplitude main menu key and set Atten Lvl to 0dB and Reference Level to –50 dBm.
4. Press the Pre Amp On/Off submenu key to turn it On.
5. Press the Detection submenu key, then press RMS/Avg (red dot appears on the RMS/Avg label).
6. Press the BW main menu key and select RBW of 100 kHz. Press the VBW submenu key and select VBW of
1kHz. Toggle the VBW/Average Type submenu key and ensure Log is selected.
7. Press the Freq submenu key and enter into the MS272xC the Start and Stop frequencies from Table A-61,
“Spectrum Analyzer DANL (Preamp On)” on page A-34.
8. Wait until one sweep has been completed.
9. Press the Marker main menu key, and press Peak Search.
10. Record the marker reading in the “Measured dBm (100 kHz RBW)” column in Table A-61.
11. Repeat Step 7 through Step 10 for the preamp On measurements, using the Start and Stop frequencies
listed in Table A-61.
12. For each measured 100 kHz value inTable A-61, convert the value to 1 Hz RBW value by subtracting
50 dB. (For example, if the marker shows a value of –110 dBm at 100 kHz RBW, then the calculated
value at 1 Hz RBW is –160 dBm.) Enter the calculated values in Table A-61. Example equation:
(–110 dBm) – (50 dB) = –160 dBm
Preamp Off Procedure
13. Press the Amplitude main menu key.
14. Set Reference Level to –20 dBm, and ensure the preamp is set to Off.
15. Repeat Step 7 through Step 12 for the preamp Off measurements, using Start and Stop frequencies that
are listed in Table A-62, “Spectrum Analyzer DANL (Preamp Off)” on page A-34.
16. Enter the Measured dBm and calculated 1 Hz RBW values in Table A-62.
17. Stop at the applicable frequency limit of the model under test as listed below:
• 9 GHz for MS2722C
• 13 GHz for MS2723C
• 18 GHz for MS2724C
• 32 GHz for MS2725C
• 43 GHz for MS2726C
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