ANSI SCTE 109-2016 pdf free download – Test Procedure for Common Path Distortion (CPD).
The purpose of this document is to establish the standard methodology used to measure Common Path Distortion (CPD) in Cable Telecommunications Systems. Please note that this procedure is a very unique procedure for measuring Common Path Distortion and distinguishes itself from other similar procedures in the following ways:
• Single port measurement, measures reflected energy
• Inject two forward carriers separated by 6 MHz and measure return beat at 6 MHz
• Used to verify performance of single port passives such as terminators or passives with all other ports terminated. Designed to be consistent with the mechanisms that cause common path distortion in outside plant.
2. Normative References
The following documents contain provisions, which, through reference in this text, constitute provisions of this document. At the time of Subcommittee approval, the editions indicated were valid. All documents are subject to revision; and while parties to any agreement based on this document are encouraged to investigate the possibility of applying the most recent editions of the documents listed below, they are reminded that newer editions of those documents might not be compatible with the referenced version.
2.1. SCTE References
• ANSI/SCTE 144 2012: Test Method for Insertion Gain and Loss, Frequency Response and Bandwidth
2.2. Standards from Other Organizations
• No normative references are applicable.
2.3. Published Materials
• No normative references are applicable.
3. Informative References
The following documents might provide valuable information to the reader but are not required when complying with this document.
Each of these procedures targets a different measurement for a unique purpose. They are independent, are specifically applicable to the device being measured, use the test equipment commonly available at the manufacturing sites used to make the device being tested, and directly measure the impairment that must be controlled. The key differences are whether they are designed for actives or passives and whether they are single port or two port measurements. Other differences are the types of distortion products being measured and the filters required to do so.
3.1. SCTE References
• ANSI/SCTE 115 2011: Test Method for Reverse Path (Upstream) Intermodulation Using Two Carriers
• ANSI/SCTE 126 2013: Test Method for Distortion of 2-way Active Amplifier Caused by Insufficient Isolation of Built in Diplex Filter
• ANSI/SCTE 145 2015: Test Method for Second Harmonic Distortion of Passives Using a Single Carrier
3.2. Standards from Other Organizations
• No informative references are applicable.
3.3. Published Materials
• No informative references are applicable.|
7. Upstream Passband Characterization
1. Calibrate the network analyzer for a transmission path measurement, from 5 to 42 MHz, per the manufacturer’s instructions.
2. Set up the equipment as shown in Figure 1 – Upstream Passband Characterization and terminate any unused ports.
Note: The bi-directional amplifier may be DC powered, eliminating the need for the AC power supply and power inserter.
3. Measure and record the frequency response and gain of the upstream passband from 5 to 42 MHz.
(Reference ANSI/SCTE 144 2012: Test Method for Insertion Gain and Loss, Frequency Response and Bandwidth. This is defined as ‘Gain.’
8. Stimulus Setup
1. Calibrate the spectrum analyzer per the manufacturer’s instructions.
2. Set up the equipment as shown in Figure 2 – Stimulus setup. Make sure to use the same cables used in Section 7, Step 2.
3. Set the resolution bandwidth of the spectrum analyzer to 30 kHz.ANSI SCTE 109 pdf download.