User manual MCINTOSH MR67 SERVICE MANUAL

[. . . ] In multiplex broadcasting, both left and right channels of a stereo program are transmitted over one FM station. The simple broadcasting of left channel and right channel needed one basic improvement. [. . . ] A new broadcast technique called matrixing was developed to overcome this problem. In the new technique the left and right programs (L + R) are added electronically. The L + R signal is centered on a portion of the station's assigned spectrum called the main carrier. At the same time the left and right programs are subtracted (L- R). MA6 The L-- R signal is centered on another portion of the station's assigned spectrum called the sub-carrier. (The FCC also permits the stations, if they choose, to use another part of the assigned spectrum for non stereo music transmission. The multiplex unit electronically protects your stereo listening by preventing SCA from interfering. ) In a FM tuner receiving multiplex, the signals are again matrixed. Four wood screws are supplied with the MA6 to secure it. END VIEW END VIEW MA6 MULTIPLEX DECODER Figure 1. MA6 Multiplex Adapter Connected to the MR67 Back Panel Showing Multiplex Adapter End View. CONNECTING The MA6 multiplex adapter power cable is the gray cable attached to the multiplex adapter chassis. Align the prongs of the plug with the power receptacle marked FM MULTIPLEX POWER on the back panel of the MR67 stereo tuner and plug the connector in. Use these cables to complete the connection of the MA6 to the MR67 Stereo Tuner. Connect the cables as follows: 1) Connect a cable between the receptacle marked INPUT on the MA6 chassis to the receptacle marked FM MULTIPLEX OUTPUT on the back panel of the MR67. 2) Connect a cable between the receptacle marked OUTPUT 1 on the MA6 chassis to the receptacle marked MULTIPLEX INPUTS 1 on the back panel of the MR67. [. . . ] 2) Connect a cable between the receptacle marked OUTPUT 1 on the MA6 chassis to the receptacle marked MULTIPLEX INPUTS 1 on the back panel of the MR67. 3) Connect a cable between the receptacle marked OUTPUT 2 on the MA6 chassis to the receptacle marked MULTIPLEX INPUT 2 on the back panel of the MR67. IMPORTANT The numbers 1 and 2 on the back panel of the MR67 designate the left and right channels, respectively. ANTENNA CONSIDERATIONS For the satisfactory operation of a multiplex tuner, more signal is needed than for monophonic reception. [. . . ]