VideoEase MonoPro XLR Application Guide
© MuxLab Inc. 2005-2006
7
Using Spare Twisted Pairs from a LAN Connection
In some installations where a point-to-point audio-video connection is needed and it is not
practical to add twisted pair cable, there is the possibility of using spare twisted pair cable that is
behind the wall. For example if an Ethernet 10/100 LAN is installed and there is a LAN outlet
connecting two rooms between a PC and a LAN hub, it may be possibly to use the unused
twisted pairs from this connection. Ethernet 10/100 requires two (2) twisted pairs. These
twisted pairs must be terminated on pins 1&2, 3&6 of the RJ45 jack. Assuming a four-pair
Cat 5 cable was installed between the PC and the hub, there may be two unused twisted pairs
available behind the wall if they have not already been used for other services.
Assuming the spare pairs are available, the two spare twisted pairs could be diverted to a
second and/or third RJ45 outlet at both ends. This would allow up to two audio-video
channels to be transmitted via Cat5 between the two locations. The following diagram shows
how the two spare twisted pairs could be used to transmit stereo-audio or composite video and
monaural audio from one room to another.
In regard to crosstalk, there will be no interference between the audio-video signal and the
LAN signal under the same Cat5 cable jacket.
