3-2 Option 31, GPS Frequency Accuracy Verification Chapter 3 — Options Verification
3-4 PN: 10580-00342 Rev. D MS2720T MM
GPS Option Bias-Tee Voltage Verification (Option 31)
The following test verifies the GPS Antenna Bias-Tee Voltages of Option 31 in the model MS2720T
Spectrum Master.
Equipment Required for MS2720T
• Adapter SMA to BNC(f), Pomona 4290 or equivalent
• Adapter GPS Terminator, Amphenol B1004A1-ND3G-93R-0.05-1W or equivalent
Procedure
1. Connect the external power supply (Anritsu PN 40-168-R) to the MS2720T Spectrum Master.
2. Press the On/Off key to turn on the MS2720T.
3. Set the MT822xB to Spectrum Analyzer mode and preset the instrument.
4. Press the Shift key, and then the System (3) key.
3.3 V Test
5. Connect the 4290 Adapter to the GPS Antenna SMA connector.
6. Connect the GPS Terminator to the 4290 Adapter.
7. Ensure the 3.3V setting on the GPS Voltage submenu key is selected (underlined)
8. Turn GPS On by toggling the GPS submenu key so that the On text is underlined.
9. Select the GPS Info submenu key. Record the GPS Antenna Current reading in the “Measured Current
Value” column of Table 3-1, “Option 31, GPS Receiver Bias-Tee Verification” on page 3-4 and verify that
it is within specification.
5V Test
10. Press the Escape key to dismiss the GPS Info dialog box.
11. Press the GPS Voltage submenu key and select 5V.
12. Select the GPS Info submenu key. Record the GPS Antenna Current reading in the
“Measured Current Value” column of Table 3-1 and verify that it is within specification.
Table 3-1. Option 31, GPS Receiver Bias-Tee Verification
Voltage Measured Current Value Specification
3.3 V mA 32 mA ±15% (27.2 mA to 36.8 mA)
5.0 V mA 55.6 mA ±15% (47.3 mA to 63.9 mA)