Neptune R450 MC, Installation And Maintenance Manual

Page: 76 / 104

Appendix A
62 R450 Mini Collector Installation and Maintenance Guide
Using the AEA 140-525 Antenna Analyzer
Complete the following steps to configure the analyzer.
1 Turn the analyzer ON .
2 Type the frequency: 46000 .
3 Press Enter .
4 Using the width buttons, set the value next to WID on the screen
to 20 .
5 Set the reading to return loss by pressing F1 three times. (Press it
slowly; the unit should beep each time.)
Figure 71 AEA Antenna Analyzer
Taking the Reading and Calculating VSWR
1 Connect the analyzer to the feed line in place of the R450 MC.
2 Configure the analyzer using the preceding procedure.
3 Be sure there is not a vertical line running through the display in the
plot area. If there is, press EXAM PLOT and it should go away.
4 Allow the analyzer reading to stabilize, between 10 and 20 seconds.
5 Press EXAM PLOT to freeze the display.
6 Using the FREQ arrows, move the cursor (the vertical line in the
middle of the screen) to approximately the R450 MC's frequency.
(It moves to within 100KHz of a frequency.)
7 Read the value next to RETL on the display. This is the return loss
value.
8 Based on the coax type and the feed line length, find the loss
attributed to the coax using the Coax Cable Loss Table on page 60.
9 The adjusted return loss is calculated by the formula:
Return Loss (from Table) - (2 x Cable Loss) = Corrected Return
Loss
10 Using the Corrected Return Loss value, find the VSWR using the
Power Measurement to Return Loss and VSWR Conversion Table
on page 59.
11 Move the cursor to within 100KHz of the R450 MC's receive fre-
quency.
This procedure assumes that the analyzer has not been
configured prior to use.