1. Stereo Beacon: The MPX-100 features an exclusive Fisher Stereo Beacon that automatically illuminates when you tune to a multiplex program and turns off when the station reverts to ordinary monophonic transmission.

  2. Automatic Switching System: The Fisher Automatic Switching System senses whether the program transmitted is stereo or monophonic and switches the MPX-100 into the proper operating mode. This eliminates the need to manually switch between stereo and mono on your adaptor.

  3. Noise Filters: The MPX-100 includes two separate noise filters. One filter affects the noise in the subcarrier only, providing full-frequency response. The other filter is designed for reception of multiplex signals under more challenging conditions.

  4. Feedthrough Connections: Even when the MPX-100 is turned off, it provides feedthrough connections for all types of tuners.

  5. Controls: The MPX-100 has three controls:

    • Separation Control: Adjust this control to provide the maximum degree of stereo separation between channels for your specific tuner model.
    • Output Level Controls: These rear-panel controls allow you to match the MPX-100 with tuners having low-level or high-level outputs.

  6. Tube Complement: The MPX-100 consists of five tubes: 1-12AT7, 1-6AB4, 1-6AU6, 1-ECH84, and 1-12AX7.