> ## 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.

# Phone lines connection

> Studio link using landline and Bluetooth mobile phone

When the unit broadcasts through Internet, landline (POTS) or mobile phone can be used as backup transmission method.\
Or if transmission is done using a Bluetooth mobile phone, a landline can be used simultaneously as mobile backup transmission.

The configuration of the lines to operate as links is:

<Tabs>
  <Tab title="Line as link">
    It is also possible to use a phone line as **main transmission channel**.

    * In **PGM** position, studio return is removed from CUE monitoring and added to program mix.
    * The **mic TALK** is not sent to the studio.
    * It is recommended to use the line in **PGM** position, to prevent the talkback microphone from accidentally going on air.
    * If studio return monitoring is not needed: keep the **PGM knob closed**.
    * To listen to return: open the **PGM** knob → studio signal is heard in all headphones monitoring PGM mix.
    * Signal sending to the lines is in **mix-minus** mode: signal coming from studio is removed from the send, avoiding feedback.
  </Tab>

  <Tab title="Line as backup">
    While MX2200 broadcasts through **Internet**, landline or mobile phone can be used as **backup method**.

    * When the line is in **CUE** position, studio return is sent only to headphone monitoring.

    <Info>
      Once the call is established, studios always receive the **PGM** mix, regardless of whether the line is in **CUE** or **PGM** mode.
    </Info>

    * If **TALK** is pressed on that line, the talkback microphone is sent to the studio through that line.
    * This condition allows the MX2200 operator to talk privately with the Studio while the console broadcasts over Internet.
  </Tab>
</Tabs>

<Note>
  More details about line operation in [Using phone lines](/en/mx2200/mx2200-op-lineas-intro)
</Note>

***

## Studio reception

* Phone calls are received at the studio through **telephone hybrids and conventional interfaces**.
* All **Solidyne** consoles support standard **POTS** lines and **Bluetooth** interfaces to link mobile phones.