David, I've read the responses to your question and would like to add:
This same idea came up while I was at Racal-Vadic in the 1979. We looked very carefully at the what occurred when an RJ-11 was plugged into an RJ-45 jack. The following was noted: 1. The body of the RJ-11 does not have a recesses for the 2 outside contacts (pins 1 & 8) of the RJ-45 jack. The body of the plug causes contacts 1 & 8 to be forced back into the RJ-45 jack deforming them. 2. The deformation causes the electrical connection of pins 1 & 8 to be unreliable if RJ-45 jack is subsequently used in an RJ-45 application. 3. Some RJ-11 manufacturers cut corners by not building the body of the plug exactly as AT&T originally specified. As a consequence they fit too loosly in the RJ-45 jack and make poor electrical contact. I actually tried it again in my lab with a new RJ-45 jack, and concluded pins 1 & 8 are deformed causing unreliable electrical contact. In my opinion it will be a problem out in the field. Just a Joe Randolph stated and experienced. I also agree there will be approval problems in some countries. Duane Marcroft Telecom and Data Communications Consultant >Hello listmembers, > >Here is an interesting question put to me by our design engineers. They >want to >use RJ-45 jacks on all telephone interface types, including a standard >telephone >interface. Is there any problem from an approvals perspective using an RJ-11 >plug in an RJ-45 jack? Our designers claim they fit, but it seems forced >to me. >Opinions? > >Regards, > >David. > >David Gelfand >Approvals Group Leader >Memotec Communications Inc.
