User guide

Table Of Contents

Distance-To-Fault (DTF) Transmission Line Test

The Distance-To-Fault transmission line test verifies the performance of the transmission

line assembly and its components and identifies the fault locations in the transmission line

system. This test determines the return loss value of each connector pair, cable component

and cable to identify the problem location. This test can be performed in the DTF–Return

Loss or DTF–SWR mode. Typically, for field applications, the DTF–Return Loss mode is

used. To perform this test, disconnect the antenna and connect the load at the end of the

transmission line.

Required Equipment

Site Master Model S331D

Precision Open/Short, Anritsu 22N50 or

Precision Open/Short/Load, Anritsu OSLN50-1 or

Anritsu InstaCal Module, ICN50B

Precision Load, Anritsu SM/PL-1

Test Port Extension Cable, Anritsu 15RNFN50-1.5-R

Optional 510-90 Adapter, DC to 7.5 GHz, 50 ohm, 7/16(F)-N(M)

Device Under Test

Transmission Feed Line with Load

Procedure - DTF - Return Loss Mode

The following steps explain how to make a DTF measurement in return loss mode.

Step 1.

Press the MODE key.

Step 2.

Select

DTF-Return Loss using the Up/Down arrow key and press ENTER.

Step 3. Connect the Test Port Extension cable to the RF port and calibrate the Site Mas-

ter as described on page 3-2.

Step 4. Save the calibration set up (page 3-10).

Step 5. Connect the Device Under Test to the Site Master phase stable Test Port Exten-

sion cable. A trace will be displayed on the screen as long as the Site Master is

in sweep mode.

Step 6.

Press the FREQ/DIST key.

Step 7. Set the

D1 and D2 values. The Site Master default for D1 is zero.

Step 8. Press the

DTF Aid soft key and select the appropriate Cable Type to set the

correct propagation velocity and attenuation factor.

NOTE: Selecting the right propagation velocity, attenuation factor and distance

is very important for accurate measurements, otherwise the faults can not be

identified accurately.

Step 9.

Press SAVE DISPLAY (page 3-10) name the trace, and press ENTER.

Step 10. Record the connector transitions.

Chapter 4 Cable & Antenna Measurements

4-7