User's Manual Part 2

RBS 2308 and RBS 2309 User’s Guide
5. Repeat step 4 for “S
hort” and “Load” according to the step-by-step
instructions on th
e screen.
6. When the c alibrati
on is complete, disconnect the calibration equipment
from the Test Port
Extension Cable.
After the calibra
tion, the display shows “CAL ON” as long as the calibration
is valid.
6.2.3 Entering Cable P
arameters
To achieve accur
ate DTF test results, the correct cable parameters, velocity
factor, and atte
nuation (dB/m) for the feeder type must be entered.
1. Press the MODE ke
y and select “DTF-SWR” by using the Up/Down arrow
key. Press ENTER
.
2. Press the DTF-A
ID 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 b
elow. Press ENTER.
5. Use the Up/Down
arrow key to select “PROP VEL”. Press ENTER.
6. Enter the
relat
ive velocity
for the type of feeder being tested, from the
table below. P
ress ENTER.
Table 19 Veloc
ity Factor and Attenuation for Different Cables
Attenuation, dB/m (CABLE LOSS)
Feeder Type
Andrew
Velocity
Factor
(PROP
VEL)
GSM
800
GSM
900
GSM
1800
GSM 1900
1/4-in. LDF1
0.86 0.124 0.129 0.189 0.195
1/4-in. F SJ1 (flex)
0.84 0.179 0.186 0.270 0.278
3/8-in. LDF2
0.88 0.106 0.110 0.161 0.166
92 EN/LZT 720 0027 Uen R8A 2006-06-27