
Revision 9.0
February 2012
12 Technical Assistance: 1-866-228-3762 TAC@jdsu.com
© 2012 JDSU. All rights reserved.
VDSL2 QUICK CARD
RFL Test
RFL Test Connections and Ohms
Helpful Hints and Tips
Distance to Strap (DTS): During RFL testing, it is important to keep DTS as short as possible due to dis-
tributed leakage -- small amounts of leakage that occur even over a good wire. More of this leakage is present
over longer distances. erefore, to keep DTS as short as possible, technicians can sectionalize the cable by
using the HST-3000’s Ohmmeter to locate the section of cable that contains the fault, then stop and test just
that section.
e Good Pair and Leakage: Before performing RFL, it is important to verify that the good pair or wire is
actually good by using the HST-3000’s Leakage mode Ihmmeter. If leakage is present, the leakage should be
500 times greater than the fault size on the bad wire or the results will be aected. After conrmation that the
pair has little or no leakage, the leads can be strapped to the faulted wire and RFL testing performed.
Testing from Both Ends: Performing RFL testing from both ends and comparing the results to see if they
agree can help pinpoint the location of the fault. If the results conict, this may indicate other problems and/
or an inaccurate conversion.
Connections and Ohms: It is important to take into consideration that the wires, adapter, or screws that con-
nect the HST-3000 to the pair also may introduce levels of resistance. For example, if the technician connects
the clips to corroded screws, this will add resistance and cause an inaccurate measurement.
Testing Multiple Pairs: It is important to test multiple pairs if there is more than one faulted pair in a count
or binder. Typically, the faults found using RFL are located in the same area as other faults; however, the dis-
tance to each fault may vary slightly due to the make up of the cable. Additionally, as more pairs are tested, the
severity of the faults can provide insight as to when it is time to repair the cable. Because unusual line condi-
tions can change and aect RFL, the same pairs should be tested multiple times to validate results and ensure
accuracy.
Load coils: Load coils can make the pair’s distance appear longer by a range of 91 feet to more than 480 feet.
To derive the correct distance, technicians must subtract the designated amount (See Table 6), which is based
on a 5-foot stub at 70 degrees Fahrenheit F. It is important to know the load’s location so that the correct
amount is subtracted from the correct section.
Code 19 AWG 22 AWG 24 AWG 26 AWG Ohms
632
470 235 147 91 4.14
652
484 242 150 94 4.17
662
480 240 149 96 4.25
Table: 6 - Load Coil Corrective Distance