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The combination of SUPER-STORE and WAVE-VIEW
also make a good tool for TDR training. Students or new
employees can use the computer as though it were a
TDR, which keeps the TDR in the field. In addition, a
variety of sample waveforms can be stored. Various
cable spans and types, faults, system components and
samples of known cable conditions can all be recalled
and studied.
4.5 Detecting Theft of Service
A TDR is an excellent tool to determine if a device,
such as a television, VCR or Converter, is connected
to the end of a drop cable inside a residence.
A TDR
test of a cable with an open end has a very defined
signature (waveform), which is easily recognizable.
A waveform with an open end (upward reflection)
simply indicates there are no devices connected
and, most likely, no probable theft of service.
To determine theft of service, the following guidelines
are recommended:
1. Once an illegal tap is located, the technician will
disconnect it from service, document the time and
date and possibly confiscate the coaxial cable.
2. Test and store the line connected to the house with
the TDR every time you see an illegal tap.
For safety
reasons, it is usually necessary to test the cable and
store the information as quickly as possible.
Once
connected, SUPER-STORE allows the technician to
store the waveform in different settings in a matter
of seconds.
Later, the information can be recalled
and adjusted as if the TDR were still connected to
the cable under test.
When testing into multiple unit
dwellings, it is a good idea to use at least two differ-
ent pulse widths:
the smallest pulse width available
and another to give you more distance.
3. Leave a note on the customer’s door explaining
what was found and how they can call to get ser-
vice installed.
If the problem repeats itself, it may be necessary to
inform the customer that legal action may be taken
if the problem persists.
Documentation may include photographs, affidavits
and any evidence found on the scene (i.e. homemade
connections and waveforms from a TDR).
If a cable is illegally connected and running directly
to a dwelling, that resident may still claim he/she had