• TB3 Tx port to the S412E RF In Port (use attenuator as needed)
• TB3 Rx port to the S412E Signal Generator Output Port
Warning
The maximum input power the S412E can handle is +33 dBm. Care must be taken not to exceed this power level as it may damage the RF Input of the S412E. It is highly recommended that an attenuator be used if the Tx power output of the TB3 base station is greater than +30 dBm.
An optional attenuator may be used on the signal generator output if very low output signal levels are desired at the TB3 Rx port.
Airbus TB3 Base Station Setup
2. Connect the TB3 base station to a PC with the test software.
S412E Setup
3. Set S412E to TETRA Analyzer Mode.
4. Ensure that the Modulation Type is set to “Base Station”
Setup -> Mod Type = Base Station
5. Set S412E Frequency:
• Set Rx frequency to Tx frequency of TB3
• Set Tx frequency to Rx frequency of TB3
6. Set the S412E Amplitude:
• Set Input and Output Offset to the appropriate Loss. This also compensates for the loss through the attenuators, if external attenuators are used. Both Input and Output port offset levels must be set properly.
• Set the Reference Level to an appropriate setting (a few dB higher than the expected TB3 Tx output level). This is to avoid overdriving the ADC.
• Set the Output Level to your desired test level. Note that losses and external attenuation will be taken into account by the offset setting used earlier. If you want –110 dBm output, set the Output Level to –110 dBm.
7. Set up TETRA Base Station Receiver Sensitivity Mode:
Measurement -> TETRA BS Sensitivity -> Base Station = Airbus TB3 0 or 1
• Airbus TB3 0 will set the ECC to 0
• Airbus TB3 1 will set the ECC to Airbus Recommended Test Default
Set Up Airbus Test Software
8. Make sure the Airbus BS is transmitting and verify that the ECC displayed on the S412E is what is expected.
9. Do not start measuring the BER until the S412E signal generator starts transmitting.
10. Start the S412E BS Sensitivity test by selecting the “Start Test” button in the TETRA BS Sensitivity menu.
11. WAIT for the “Start Test” button to change to “Stop Test” – this lets you know that the signal generator has synchronized to the BS frame structure and is playing the TCH/7.2 signal.
12. Start the BER measurement on the TB3 BS.
• The signal from the S412E will restart every 60 seconds, so make sure that the BER measurement is made within this time interval.
• You can now go to the Amplitude menu and change the Amplitude to your desired level.
Note
If you go back to the BS Sensitivity menu, the test will stop and you can restart it by following the same procedure.
