摘要 |
<p>A passive conference bridge is coupled to telephone lines through pairs of panel mounted plug-in jacks to establish conference call connections with balanced input/output impedances. Test equipment is plugged into the jacks for connection to the bridge circuit and/or telephone lines. The telephone lines are disconnected from a leg of the bridge circuit through one of the jacks of each pair and a terminating resistor is thereby inserted into the disconnected bridge leg.</p> |