User guide

DM-14B & DM-14C User’s Guide
60
f) Measurement example:
- Recall from the menu window the previously saved cable number or insert it manually if the distribution under test
uses a type of cable with parameters which are different from those saved.
- Using the “UP”, “DOWN” and “ENTER” keys, position Marker 1 in a curve dip and Marker 2 in the curve
dip nearest to Marker 1. Read the distance calculated by the meter in the “DISTANCE” window (see example
below).
NOTES:
1. PROPAGATION SPEED MEASUREMENT:
If the propagation speed percentage is not known (because it is not specified by the manufacturer), you can
calculate it using the reflectometer function.
With reference to the connection diagram on page 40, connect the “T” adapter at the output to 5 meters of
coaxial cable whose propagation speed is unknown, without closure resistance. Then recall the menu and
vary the propagation speed percentage until 5.0 m appears in the “DISTANCE” window. The resulting
propagation speed value obtained is the one related to the cable you are using.
2. PROGRAMMING MODIFICATION:
To vary the programming of any cable, simply change it manually and the new parameter will store
automatically.
Reflectometer measurement
example
Menu setting:
Cable number, type, propagation speed and
measurement unit.