Coaxial Cable Testing - DSX CableAnalyzer
Certifying coaxial cabling with Versiv requires the optional DSX-COAX coaxial adapters and either DSX-5000 or DSX-8000 copper modules. The adapters are marked “DSX-CHA003 COAX ADAPTER.”
Possible Mesurement Parameters
Versiv units will test the coax cable to 1002MHz.
Selecting a Cable Type
Cable types available in Versiv
Selecting a Test Limit
Click Here to see the Versiv Limit Lines document for a breakout of the Coax limits in section 2.1 (see Index on Page 1).
Setting the Reference
It is important to set the reference at least every 30 days. You do not have to set the reference every time the adapters are removed. However, for optimal accuracy, you may wish to set the reference each time you use the coax adapters.
Connect the two Versiv units together as shown in the diagram below:
The reference lead cannot be more than 20 inches (0.5m); otherwise the DSX will not permit the reference to be set.
Although preferable to set the reference with the supplied 75 Ω reference cable, you can also set the reference with a 50 Ω cable.
The Autotest Result
Below is an example of an autotest result for the TIA 568C.4 CATV RG6 :
You will often see an “i” next to the test parameter. This indicates that the measurement is for Information only. There is no limit assigned to that test parameter. Most users will know what the maximum value for their application should be.
HDTDR has a green check mark (pass) next to it. How can there be a limit for HDTDR? The DSX CableAnalyzer automatically looks for an impedance anomaly greater than 15%. If the impedance anomaly is greater than 15%, HDTDR will fail (red “x”).
Impedance Anomaly
This is the location(s) on the cabling where the cablings impedance changes abruptly. During a coaxial cable test, the test tool detects and reports the position of the largest impedance anomaly (if any are present) on the cable.
The test tool reports an anomaly if 15% or more of the test signal is reflected. Here is an example of an HDTDR trace with an anomaly:
Anomalies can be caused by:
- Bad connection(s)
- Cable compression (tight cable ties, pinches, kinks, etc.)
- Mismatch of cable types
- Water in the cable jacket
- Excessive loading at coaxial cable tap
- Incorrect terminator value
Custom Coax Test?
There is currently no option to customize a coax test other than to change the cable type and NVP values. It is anticipated that this will provide enough flexibility to allow testing in the majority of coaxial installations.