Fan Replacement; Performance Testing; Power And Gain Performance Test - CPI S5CIA Installation And Operation Manual

M
AINTENANCE
6.4.4

Fan Replacement

After 50,000 hours of operation or if the fans have problems, the fans should be replaced. Contact
CPI service for instructions.
Note:
shown, depending on the site environment.

6.5 Performance Testing

Once a year perform the tests for power and gain, radiation levels, and record their results. If the
results are not satisfactory refer to the Indoor SSPA service manual to troubleshoot and repair the
Indoor SSPA.
6.5.1

Power and Gain Performance Test

Follow these steps to test the Indoor SSPA for power and gain. Record the results on the "Power
and Gain Test Data Sheet" provided in table 6-4.
1. Connect equipment as shown in figure 6-1 "Performance Test Setup".
2. Turn off the synthesizers RF output. Set the input drive level to minimum and the Indoor
SSPA attenuation to maximum.
3. Set the synthesizer to center wave (CW). The same frequencies should be used every time
preventative maintenance is performed so that a trend chant can be developed.
4. Turn the synthesizer's RF output. Increase the drive level until the Indoor SSPA has reached
rated power.
5. Calculate the gain at rated power and record on the test data sheet.
Gain = P (dBm) – P
o
6. Reduce the drive level until the Indoor SSPA is at rated power –10dB. It may be necessary to
use a 10dB fixed attenuator at the input to achieve a reliable input power measurement.
7. Calculate the small signal gain, and record the result on the test data sheet.
8. Repeat for the low and high frequency band of the Indoor SSPA.
6-8
Fan Replacement may be required more or less frequently than
(dBm)
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