Have you ever wondered what you sound like on air? Many radio amateurs wouldn't have a clue what they sound like over the airwaves.

Have you needed to set the mic gain and not been able to find someone to talk with on air?

There is a great talk-back/check function that is available on most IRLP nodes.

If you type in a DTMF 9990 and then say a sentence and release the PTT button, the IRLP node will, after a short delay, playback your sentence over the air.

This allows you to check quality, levels, etc.

To stop this mode just type the normal DTMF 73 and this will cancel the talk-back mode.