11. Press the Calibration key.
12. At the CALIBRATION menu display, use
the Menu up-down keys to highlight
START CAL, then press the Select key.
13. At the PRECISION RETURN LOSS
CALIBRATION menu display prompt,
connect the Offset SWR Autotester to
Input A, if you have not done so yet.
14. Connect the precision air line to the Off-
set SWR Autotester test port. Position
the air line pointing vertically upward.
Downward or horizontal positions make
connector pin alignment difficult.
NOTE
Ensure that the beadless end of
the precision airline is at the
measurement connection point.
15. Press the Select key when ready.
16. At the PRECISION RETURN LOSS
CALIBRATION menu prompt, connect
the Open to the beadless end of the air-
line. Press the Select key to start the cali-
bration.
17. Verify that the display resembles that
shown in Figure 5.
CAUTION
During both calibration and mea-
surement, be sure to properly
align the beadless connector of the
airline. When the connectors are
mis-aligned, a spike will usually
be visible on the display.
18. At the next menu prompt, remove the
Open and connect the Short to the
beadless end of the airline. Press the Se-
lect key to start the calibration process.
19. At the next menu prompt, remove the
Short and connect the 50 Ohm Termina-
tion to the beadless end of the air line.
Press the Select key to start the calibra-
tion process.
20. When the calibration is complete, remove
the 50 Ohm Termination.
21. Connect the SM/PL termination to the
beadless end of the air line and press the
Select key to begin the measurement.
22. Observe that the waveform displayed re-
sembles that shown in Figure 6.
23. Press the Cursor On/Off key to On.
24. Observe the Cursor menu readout. The
minimum return loss reading for the
SM/PL termination should be 42 dB.
6 Site Master S113B/S331B MM
1 0 . 0 d B / D I V O F F S E T1 : P R E C S N R L ( A )
2 : O F F
+ 0 . 0 d B
0 . 4 G H z / D I V
S T A R T : 0 . 0 1 0 0 G H z
4 0 1 p t s
S T O P : 4 . 0 0 0 0 G H z
L E V E L + 7 . 0 d B m
54147A
P R E C I S I O N
R E T U R N L O S S
C A L I B R A T I O N
C O N N E C T O P E N
T O A I R L I N E
P R E S S S E L E C T
W H E N R E A D Y
Figure 5. Example of a Good Connection
1 0 . 0 d B / D I V O F F S E T1 : P R E C S N R L ( A )
2 : O F F
+ 0 . 0 d B
0 . 4 G H z / D I V
S T A R T : 0 . 0 1 0 0 G H z
4 0 1 p t s
S T O P : 4 . 0 0 0 0 G H z
L E V E L + 7 . 0 d B m
54147A
C U R S O R
1 : - 4 6 . 0 2 d B
P R E S S S E L E C T
F O R
C U R S O R M E N U
2 . 4 0 5 0 G H z
Figure 6. Direct Readout of the Precision Return Loss
