> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solidyne.ar/llms.txt
> Use this file to discover all available pages before exploring further.

# MPX Connection

> Multiplex output (MPX) and modulation adjustment.

The **Audimax 362HD** features dual MPX outputs with independent level adjustments.\
This allows connecting a backup transmitter or dedicating it to a nighttime transmitter.

<img src="https://mintcdn.com/solidyne/St-QpEDuvK_Tklee/images/362/362-trasero-mpx.png?fit=max&auto=format&n=St-QpEDuvK_Tklee&q=85&s=1c7dea893cb4694ed451ce6f4de9f9a2" alt="362 Rear Mpx Pn" title="362 Rear Mpx Pn" className="mx-auto" style={{ width:"32%" }} width="1035" height="638" data-path="images/362/362-trasero-mpx.png" />

* Output connectors are **BNC** type.
* For MPX connection, use **75 Ohm** coaxial cable (CCTV standard).
* Cable length should not exceed **25 meters**.

<Warning>
  Proper ground distribution is essential.
</Warning>

<Note>
  When connecting to the transmitter's MPX input, ensure the transmitter's internal pre-emphasis network is disabled (flat response 20 - 100 kHz).
  Pre-emphasis in the Audimax 362HD is factory-set, available in either 50 µs or 75 µs.
</Note>

## Adjusting to 100% Modulation

Modulation is adjusted by varying the equipment's MPX output level.\
It is recommended to use program material with **voice and strong music** (e.g., contemporary pop).

<Steps>
  <Step title="Prepare the input signal">
    * Ensure you are using the appropriate inputs (BAL/UNBAL) according to your console.
    * Adjust the console's audio level to reach **0 VU on peaks**.
    * This way, the AGC stage works at its equilibrium point.
  </Step>

  <Step title="Configure processor and transmitter">
    * Set all processor controls to their **center position**.
    * If the transmitter has modulation level control, set it to maximum.
  </Step>

  <Step title="Adjust MPX output">
    * Adjust the 362HD's MPX output level until reaching **75 kHz deviation (100%)**, measured with an **FM modulation monitor** or the transmitter's indicator instrument.
  </Step>
</Steps>

<Note>
  Some countries allow infrequent peaks up to **110% modulation** (e.g., FCC regulations in USA).\
  Needle-type modulation indicators may show peaks above 100% due to ballistic overshoots or average readings of sinusoidal signals. This does not indicate actual over-modulation in the system.
</Note>

Once modulation level is set, proceed to **customize the station's sound** by adjusting the Audimax 362HD controls.\
This process does not affect the modulation level, as the processor delivers constant peak level.