PIM analysis requires two source carrier frequencies (F1 and F2) in order to make a measurement. DTP analysis includes the two carrier frequency sources for the measurement, but only one of the sources is swept. In the DTP measurement setup, F1 Frequency is the stationary source. F2 is the second source and will be swept from the F2 Start Frequency to the F2 Stop Frequency. The default frequencies have been selected to optimize the distance resolution. Changing these frequencies will lower measurement resolution.

Dmax is the maximum horizontal distance that can be analyzed. The distance range between the Start Distance and the Stop Distance setting cannot exceed Dmax. If the cable is longer than Dmax, then Dmax needs to be improved by increasing the number of data points or by lowering the frequency span (ΔF). Note that the data points can be set to either 64 points or 128 points. For best results, Data Points should always be set to the maximum number of steps available, given the F2 swept bandwidth. You can choose 64 data points if measurement speed is critical.

When the DTP Parameters setup window is displayed, the DTP Aid menu is also displayed. The Up and Left arrow keys move the selection highlight up in the window. The Down and Right arrow keys move the selection highlight down in the window. The rotary knob moves the selection highlight in both directions. The bottom selection is the Continue button.

When any parameter is highlighted, keying in a value and pressing the Enter key or a menu key completes the setting, and the selection highlight is incremented downward in the list. You can also press the Esc key to abort these settings and return to the Freq/Dist menu or the Sweep/Setup menu, depending upon your starting point.

When numeric values are highlighted, the numeric keypad must be used to enter a value. An additional menu is displayed for distance, frequency, propagation velocity, or cable loss ((dB/ft or (dB/m). Press the appropriate units submenu key or press the Enter key to set the value. The selection highlight is incremented to the next lower parameter in the DTP Parameters setup window.

Additional selection menus are displayed when the following parameter buttons are highlighted in the DTP Parameters window:

 

The last item in the DTP Parameters setup window is the Continue button. Select this button and press the Enter key to close the DTP Parameters setup window and continue with your measurement. The menu display returns to either the Freq/Dist menu or the Sweep/Setup menu, depending upon your starting point.