Anritsu S251C - Manual (Page 54)

Procedure - Return Loss Mode
Step 1. Press the MODE key.
Step 2. Select
FREQ-RETURN LOSS using the Up/Down arrow key and press
ENTER .
Step 3. Set the start and stop frequencies, F1 and F2, as described on page 3-2.
Step 4. Connect the Test Port Extension cable to the RF Out port and calibrate the Site
Master as described on page 3-2.
Step 5. Save the calibration set up (page 3-5).
Step 6. Connect the Device Under Test to the Site Master phase stable Test Port Exten-
sion cable. A trace will be displayed on the screen as long as the Site Master is
in sweep mode.
Step 7. Press the AMPLITUDE key and set
TOP and BOTTOM values of the display.
In the example below, the TOP is set to 4, and the BOTTOM is set to 10.
Step 8. Press the MARKER key.
Step 9. Set
M1 to MARKER TO PEAK.
Step 10. Set
M2 to MARKER TO VALLEY.
Step 11. Calculate the insertion loss by averaging M1 (marker to peak) and M2 (marker
to valley) and dividing by two as follows:
Step 12.
Insertion Loss
M M
=
+
1 2
2
2 =
Avg.
2
(where Avg. is one way loss)
Step 13. Press SAVE DISPLAY (page 3-5) name the trace, and press ENTER .
Figure 4-4 is an example of a typical insertion loss measurement in return loss mode.
Chapter 4 Measurements
4-7
Figure 4-4. Typical Insertion Loss Measurement in Return Loss Mod