Use this feature with caution, as the later introduction of an interfering signal might be mis-
taken for a problem with the antenna or cable run.
If CW is on during a normal RL or SWR measurement, the Site Master will be more sus-
ceptible to interfering signals. Interfering signals can make the measurement look better or
worse than it really is.
Information Required for a Line Sweep
The following information must be determined before attempting a line sweep measure-
ment:
q
System Frequency Range, to set the sweep frequency
q
Cable Type, to set the cable characteristics for DTF measurements
q
Distance of the Cable Run, to set the distance for DTF measurements
Typical Line Sweep Test Procedures
This section provides typical line sweep measurements used to analyze the performance of
a transmission feed line system.
System Return Loss Measurement
System return loss measurement verifies the performance of the transmission feed line sys-
tem with the antenna connected at the end of the transmission line. To measure the system
return loss:
Required Equipment
q
Site Master Model S331D/S332D
q
Precision Open/Short, Anritsu 22N50
or
Precision Open/Short/Load, Anritsu OSLN50LF
or
InstaCal Module ICN50
q
Precision Load, Anritsu SM/PL
q
Test Port Extension Cable, Anritsu 15NNF50-1.5C
q
Optional 510-90 Adapter, DC to 7.5 GHz, 50 ohm, 7/16(F)-N(M)
Device Under Test
q
Transmission Feed Line with Antenna
Procedure
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, automatically by selecting a signal standard or
manually using the F1 and F2 soft keys, as described on page 3-2.
Step 4.
Calibrate the Site Master as described on page 3-2.
Step 5.
Connect the Device Under Test to the Site Master. A trace will be displayed on
the screen when the Site Master is in the sweep mode.
Step 6.
Press
SAVE DISPLAY
(page 3-14) name the trace, and press
ENTER
.
Chapter 4 Cable & Antenna Measurements
4-3