FlexCal OSL Calibration
Step 1.
The currently selected calibration method can be viewed by pressing the
SYS
key, followed by the
Status
soft key. To change the calibration method, select
the
SYS
key, followed by the
Options
soft key. Use the
CAL Mode
soft key to
select the
FlexCal
calibration mode.
Step 2.
Press the
START CAL
key. The message “
Connect OPEN or INSTACAL mod-
ule to RF Out Port
” will appear in a message box, with the calibration type in the
message box title bar.
Step 3.
Connect the calibrated Open and press the
ENTER
key. The messages “
Mea-
suring OPEN
” and “
Connect SHORT to RF Out
” will appear and the frequency
is automatically set by the Site Master from 25 MHz to 4000 MHz.
Step 4.
Remove the Open, connect the calibrated Short and press the
ENTER
key. The
messages “
Measuring SHORT
” and “
Connect LOAD to RF Out
” will appear.
Step 5.
Remove the Short, connect the calibrated Termination and press the
ENTER
key. The message “
Measuring LOAD
” will appear. An audible tone will sound
when the calibration is complete.
Step 6.
Verify that the calibration has been properly performed by checking that the
FlexCal ON
message is now displayed in the upper left corner of the LCD.
InstaCal Module Verification
Verifying the InstaCal module before any line sweeping measurements is critical to the
measured data. InstaCal module verification identifies any failures in the module due to cir-
cuitry damage or failure of the control circuitry. This test does not attempt to characterize
the InstaCal module, which is performed at the factory or the service center.
The performance of the InstaCal module can be verified by the Termination method or the
Offset method. The termination method is the preferred method in the field, and is similar
to testing a bad load against a known good load.
Termination Method
The Termination method compares a precision load against the InstaCal module and pro-
vides a baseline for other field measurements. A precision load provides better than 42 dB
directivity.
Step 1.
Set the frequency according to the device under test (cellular, PCS, GSM).
Step 2.
Press the
MODE
key and select
Freq-Return Loss
mode.
Step 3.
Connect the InstaCal module to the Site Master RF Out port and calibrate the
Site Master using the InstaCal module (page 3-6).
Step 4.
Remove the InstaCal module from the RF Out port and connect the precision
load to the RF Out port.
Step 5.
Measure the return loss of the precision load. The level should be less than 35
dB across the calibrated frequency range.
Step 6.
Press the
MARKER
key and set the M1 marker to
Marker To Peak
. The M1
value should be less than 35 dB return loss.
Step 7.
Press
SAVE DISPLAY
(page 3-14) name the trace, and press
ENTER
.
Chapter 3 Getting Started
3-5