Name: VIAVI I-Stop Reverse Test Probe for HFC Ingress Troubleshooting
Brand: VIAVI
SKU: I-Stop

Overview

The VIAVI I-Stop is a reverse test probe used as a test accessory with most signal level meters, VIAVI DSP meters, VIAVI ONX meters, the VIAVI 860 DSPi, VIAVI PathTrak/XPERTrak and ViewPoint/SST.

The probe screws into the unused KS port of a distribution tap, where a spring-loaded stinger connects a nominal 20 dB resistive test point circuit to the seizure screw. The connection is bi-directional, so a signal level meter or analyzer connected to the probe can measure forward and reverse signals as well as reverse ingress. A built-in AC/DC blocking circuit protects the connected instrument from online power up to 100 volts.

Locating ingress

With the field meter connected to the test port, the technician presses the button on the side of the probe. If the headend ingress display decreases by 4 to 6 dB when the button is pressed, the ingress source is farther from the node than the test point; ingress that does not decrease enters the system nearer to the node. The probe has little or no visible effect on forward path signals.

The I-Stop contains a patented circuit used with the VIAVI PathTrak/XPERTrak or Guardian II return path maintenance systems to track reverse ingress sources down to the nearest tap, without removing reverse pads or diplexers and without disrupting forward or reverse service.

Key Features

Taps unused KS ports for bi-directional measurements
Compatible with SLMs, reverse and forward path analyzers
Enables tracking reverse ingress to the nearest tap
Protects instruments from line power damage (up to 100 volts)
Spring-loaded stinger connects a nominal 20 dB resistive test point circuit
Patented circuit for use with PathTrak/XPERTrak and Guardian II return path systems
Little or no visible effect on forward path signals

Specifications

Insertion Loss

TAP input to output	< 1.5 dB @5 to 50 MHz Specifications vary slightly based on manufacturer of the tap that is under test
TAP input to output	< 3.5 dB @ 50 MHz to 1.2 GHz Specifications vary slightly based on manufacturer of the tap that is under test
TAP input to output (flatness)	<1.5 dB in any 150 MHz Span Specifications vary slightly based on manufacturer of the tap that is under test
TAP input to output with button depressed	≥ 4.5 dB, ≤ 8 dB @ 5 to 30 MHz Specifications vary slightly based on manufacturer of the tap that is under test
TAP input to output with button depressed (forward band)	≤ 1.0 dB Increase in Insertion Loss @ 54 MHz to 1.2 GHz Specifications vary slightly based on manufacturer of the tap that is under test

Transmission

TAP input to I-Stop output	20 ± 2.0 dB @ 5 MHz to 1.0 GHz Specifications vary slightly based on manufacturer of the tap that is under test
TAP input to I-Stop output	20 +/-4 dB @ > 1GHz Specifications vary slightly based on manufacturer of the tap that is under test

General

Test point circuit	nominal 20 dB resistive Connected to the tap seizure screw via spring-loaded stinger
Line power protection (AC/DC blocking)	up to 100 volts
Tap connection	KS port Unused KS port of a distribution tap
Headend ingress decrease with button pressed	4 to 6 dB Indicates ingress source is farther from the node than the test point