User Manual

SGD-SB2025NT-TUM, Part 1
Jan 12 Page 57 ALIGNMENT & TESTING
Preliminaries
1. On the MxTools Channel screen, program the upper, middle and lower frequencies of the
frequency band (refer to Appendix A for band split details) into three channels.
Note.
The ‘Continuous Update Enabled’ option on the MxTools Channel Edit screen should
be selected for these tests.
2. Remove the top cover from Exciter module and fit the VCO under test. As the Tx and Rx
VCOs are identical, the Rx VCO may also be tested in an Exciter. As the Rx VCO operates
at the frequencies F
RX
– 90 MHz.
3. Connect the Exciter to a working Micro Controller via 16-way ribbon cable.
4. Disconnect Exciter RF drive output CN1 from PA.
Procedure
5. Select mid channel.
6. Connect SKU from the Exciter to VCO.
7. Switch on the DC power.
8. Assert PTT and measure the RF output power on VCO SKT-6. This should be in the range
0 dBm to +3 dBm.
9. Measure the RF output level on SKU-1. This should be in the range 0 dBm to +3 dBm.
Note.
If SKU-1 is disconnected from the Exciter the loop will lose lock.
10. Reconnect SKT and SKU to Exciter.
11. Select lower channel.
12. Assert PTT and check that loop is locked.
13. Adjust trim cap CT1 on VCO for 3 VDC (2 VDC for N2 band) on SKT-1.
14. Select upper channel and check that the loop is locked and that the voltage on SKT-1 is
<18 VDC.
The following test is not required for the Rx VCO.
15. Connect the Exciter output to the CTS. Inject 1 kHz tone at nominal line input level and
check that Exciter RF output is modulated and that the depth of modulation can be controlled
through the MxTools Channel screen.
6.2.5 Microcontroller Module
Comprehensive testing of the Micro Controller can only be carried out at the Factory.