Protek A434L Operating Manual page 84

measurement resolution, is necessary to change the frequency
setting.
 Distance Setting: The maximum measurable distance is displayed
on the left side of the screen depending on the frequency setting.
Any value within the maximum measurable distance can be set.
Optimum resolution is achieved when the user setting distance is
the same as the maximum measurable distance.
Cable Setting: Selects a cable type of the feed line. By using this

key, users can select the cable stored in the instrument without
setting the detailed parameters of the cable.
 Setup: Used to change the setting of the cable parameters or
change the distance unit. It consists of the following sub menus:
Velocity: Sets the relative propagation delay of a cable. It

affects the calculation of the distance in the DTF
measurement.
 Cable Loss: Sets the loss per distance unit of a cable. It affects
the peak level of the discontinuity in the DTF measurement.
After calibration, do not change the connection of the port extension
cable or the frequency setting. It can cause a
measurement error. When the frequency setting is
changed, a warning alarm will sound and the calibration
state is changed to "Cal Off". After changing the
frequency setting, recalibrate
the instrument using the Open-Short-Load standard.
A detailed procedure for DTF setup is as follows:
Action
Frequency Setting.
Press the Freq/Dist key.
 Select the
{Enter start frequency value}
Press the Enter key.
84
Start Freq
screen menu.
Note
Additional calibration is

not necessary if a Freq
Band has been set and a
calibration has been