| 摘要 |
1,067,210. Substation circuits. A. LEVY. Dec. 6, 1965, No. 51667/65. Heading H4K. A hold key is provided which, when actuated, disconnects the handset from the incoming line and through a relay or otherwise bridges the line with a holding resistance, and at the same time connects a musical or other programme channel to the line through an inductive or capacity coupling. |
