Hi. Our IT dept, largely responsible for cabling on campus, would like to see us use the It standard of females jacks and patch cords for wiring our HDBaseT devices. I know some manufacturers specify a single cable run with no interruptions. Looking at a BICSI presentation at Infocomm this year, I see that the 2 jacks/patch cords approach is being embraced. The Do’s and Don’ts (under Do) says to use pre-made patch cables and blocks (minimally.) In the “10 Commandments” it says only if absolutely necessary. These were both written in 2014. Does anyone out there know what the HDBaseT Alliance and BICSI preferred/accepted approach is in 2017? Thanks.
HDBaseT specifies the “worst case” channel as 90m of infrastructure cable (Cat5e or better) plus two 5m patch cables (one per end). In fact, this is how HDBaseT products sent for compliance testing are actually tested.
Of course, when using patch cables (and connectors), we introduce discrepancies in the channel, meaning that the channel properties are no longer uniform. This results in additional signal reflections and attenuation which reduce the overall quality of the channel and thus erode the margins in the system. Lower margins can result in performance degradation at longer cable lengths when running high-bandwidth video formats. While HDBaseT can handle the discrepancies in the channel (like I said, that’s how the products are CTS tested), the results of the lower system margins depend upon the quality of the cable, the length of the cable and the quality of the installation.
Equipment vendors may choose to remove the risk of possible performance degradation by recommending a single cable run only. The HDBaseT Alliance guidelines also suggest that single run is better, but this is purely to be on the safe side. Both approaches should work fine if using compliant Cat cables and following our installation guidelines. Of course, the better the cable quality the less likelihood of issues arising, but that is true whether using a single run or patch cables.