Robert N. Poston
problem
Category 5 cable is so efficient at keeping out external signals that installers and technicians often have difficulty detecting tone through the cable jacket.
solution
Create an adapter using a length of cable, an 8-pin modular plug, and an 8-pin modular jack, splitting the pairs that connect the plug to the jack. Then, when testing a Category 5 cable, plug the tone generator into the adapter`s jack, and insert the adapter`s plug into the outlet you are testing.
procedure
1) To make the adapter, get a short length of cable (approximately 2 to 3 inches), an 8-pin modular plug, and an 8-pin modular jack.
2) Terminate the cable to the plug and jack, but intentionally split the pairs. To do this, connect a single wire from any pair to pin 4 of the jack and pin 4 of the plug. Connect a single wire from any other pair to pin 5 of the jack and pin 6 of the plug.
3) When you are using a tone generator to detect signals on Category 5 cables, plug the tone generator into this adapter. Then plug the other end of the adapter into the outlet you are testing. The elevated crosstalk level that results from the split pairs within the adapter will allow you to detect tone on the Category 5 cables.
This tip can be used with tone generators that include modular plugs. Banjo-style modular adapters that serve the same purpose are commercially available for use with tone generators that include alligator-style clips.
The adapter includes an 8-pin modular jack, a short length of cable, and an 8-pin modular plug.
Robert N. Poston is a cabling installer from King of Prussia, PA. He has spent 43 years as an installer, foreman, and supervisor woking with electrical and communications cabling. He is a member of Local Union 98 IBEW.