User's Manual Part 2

RBS 2109 User’s Guide
3. Press the START CAL key.
4. Connect the ‘‘Open’’ and press ENTER. Wait for the measurement to be
completed.
5. Repeat step 4 for ‘‘Short’’ and ‘‘Load’’ according to the step-by-step
instructions on the screen.
6. When the calibration is complete, disconnect the calibration equipment
from the Test Port Extension Cable.
After the calibration, the display shows ‘‘CAL ON’’ as long as the calibration
is valid.
6.2.3 Entering Cable Parameters
To achieve accurate DTF test results, the correct cable parameters, velocity
factor, and attenuation (dB/m) for the feeder type must be entered.
1. Press the MODE key and select ‘‘DTF-SWR’’ by using the Up/Down arrow
key. Press ENTER.
2. Press the DTF-AID soft key.
3. Use the Up/Down arrow key to select ‘‘CABLE LOSS’’. Press ENTER.
4. Enter the
cable loss
in dB per metre for the type of feeder being tested,
from the table below. Press ENTER.
5. Use the Up/Down arrow key to select ‘‘PROP VEL’’. Press ENTER.
6. Enter the
relative velocity
for the type of feeder being tested, from the
table below. Press ENTER.
Table 14 Velocity Factor and Attenuation for Different Cables
Attenuation, dB/m (CABLE LOSS)
Feeder Type
Andrew
Velocity
Factor
(PROP
VEL)
GSM 800 GSM 1900
1/4“ LDF1
0.86 0.124 0.195
1/4” FSJ1 (flex)
0.84 0.179 0.278
3/8“ LDF2
0.88 0.106 0.166
3/8“ FSJ2 (flex)
0.83 0.121 0.191
1/2” LDF4
0.88 0.066 0.104
1/2” FSJ4 (flex)
0.81 0.107 0.171
7
8
E
N/LZT 720 0090 Uen R1A 2004-09-17