BRX-VDSL2 User Guide
35
180-0153-001-R02
14. There is a humming noise on the
telephone (POTS) that was not
present before installing the BRX-
VDSL2
You should have the following equipment to help you
troubleshoot the problem:
- VDSL2 Test Set from vendors such as: JDSU,
EXFO …
- Standard Telephone Test set
With the house disconnected at the NID and the
BRX-VDSL2 installed on the copper pair, verify if
the audible hum noise is still present. If the noise
disappears then the problem is with the house
wiring.
Verify that the TIP-ground AC voltage matches
the RING-ground voltage and that the level is
less than 5VAC rms. If not, common 60Hz noise
may convert as audible noise on the line.
Verify that the longitudinal balance is greater than
60dB.
Verify that the Power Noise measured on the line
is lower than 80dBrnc
Verify that the Circuit Noise measured on the line
is lower than 20dBrnc
Verify that the BRX-VDSL2 chassis grounding is
properly made. Bad grounding may reduce unit
shielding efficiency and translate into higher
noise coupling.
Note:
please note that the BRX-VDSL2-X series of
VDSL2 amplifiers require the use of the Positron
BRX Power Injector to properly support concurrent
operation with a POTS service.
If the measurements for the copper pair do not match
the above guidelines, please follow the corporate
procedure to rectify the situation and verify again if
the problem is still present.
Table 9: BRX-VDSL2 Troubleshooting
