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User Manual

ManualsBrandsSimoco EMEA ManualsElectronicsSB2025NT/Atlas 4100/ Atlas 4200/ Atlas 4300
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SGD-SB2025NT-TUM, Part 1
Jan 12 Page 54 ALIGNMENT & TESTING
2. Remove the top cover from Exciter module under test and fit a known working VCO tuned for
the band to be tested.
3. Connect the Exciter to a working Micro Controller via 16-way ribbon cable.
Procedure
The test procedure for the Rx is divided into the Front-end Alignment and the IF Alignment
procedures.
Front-end Alignment
4. Switch on the DC power and check that the output voltage on pin 1 of IC8 is 5 V ± 0.2 V, on
pin 1 of IC2 is 8 V ± 0.2 V, on output of IC9 (on C66) is 8 V ± 0.2 V and on pin 1 of IC3 is 9 V
± 0.2 V.
5. Remove Jumpers E and D, and install Jumper C.
6. Connect the Tracking Generator output to CN1 and Spectrum Analyser input to CN4.
7. Set the Tracking Generator to sweep the band.
8. Adjust A4, A10 and A16 for a symmetrical pass-band around the band centre frequency.
9. Check that the gain over the band is 12 dB and that the ripple is < ±1.5 dB.
10. Check that the attenuation at the first IF image is >50 dB.
11. Remove Jumpers C and I, and install Jumpers E and H.
12. Connect the Tracking Generator output to CN4 and Spectrum Analyser input to CN5.
13. Set the Tracking Generator to sweep the band.
14. Adjust B4, B10 and B16 for a symmetrical passband around the band centre frequency.
15. Check that the maximum loss over the band is <3 dB and that the attenuation at the first IF
image is >50 dB.
16. Remove Jumper E and install Jumper D.
17. Connect the Spectrum Analyser input to CN5 and Tracking Generator output to CN1.
18. Set tracking generator to sweep the band.
19. Check for symmetrical passband around band centre frequency.
20. Check that the gain over the band is 10 dB and that the ripple is <1.5 dB.
21. Remove Jumper H and install Jumper J.
IF Alignment
22. Select the mid channel.
23. Check that LD on SKD-16 goes high indicating that the synthesiser is in lock.
24. Remove S3 (0 Ω local oscillator connection to mixer) and solder a 50 Ω coax test lead across
C60 position (Note C60 position is near a retaining screw and C60 is not fitted).