公开(公告)号：US3660620A

公开(公告)日：1972-05-02

申请号：US3660620D

申请日：1969-12-10

Applicant: BELL TELEPHONE LABOR INC

Inventor： SCHIMPF LUTHER G

IPC: H04B3/48 ,  H04M3/30 ,  H04B3/46

CPC classification number: H04B3/48 ,  H04M3/301

Abstract: A system for measuring the transmission loss in a telephone customer''s loop. A diode network is connected at the customer''s premises across the loop. At the central office two alternating current signals are impressed on the loop. One signal is a low frequency, high amplitude signal used to switch the diode network alternately into its conducting and nonconducting states, thus causing the modulation of the second high frequency, low amplitude signal. The sum or the difference frequency is filtered out and measured at the central office.

Abstract translation: 一种用于测量电话客户回路中传输损耗的系统。 一个二极管网络在客户的整个环路连接。 在中央办公室，两个交流信号印在环路上。 一个信号是用于将二极管网络交替地切换到其导通和非导通状态的低频，高振幅信号，从而导致第二高频，低振幅信号的调制。 总和或差异频率在中心局被滤除和测量。

公开(公告)号：US3492432A

公开(公告)日：1970-01-27

申请号：US3492432D

申请日：1967-03-08

Applicant: BELL TELEPHONE LABOR INC

Inventor： SCHIMPF LUTHER G

IPC: H04N21/2365 ,  H04N21/434 ,  H04J1/18

CPC classification number: H04N21/2365 ,  H04N21/4347

公开(公告)号：US3405362A

公开(公告)日：1968-10-08

申请号：US51499543

申请日：1943-12-20

Applicant: BELL TELEPHONE LABOR INC

Inventor： BADGLEY ROBERT H ,  SCHIMPF LUTHER G

IPC: G10L19/02

CPC classification number: G10L19/02