Setting up a Reference Tone:   When you power up the TU300, it is set to 440Hz.

1) Press the STREAM/CENT and the MODE button simultaneously.

2) Increase the reference tone in 1-Hz steps by pressing the MODE button.

3) Decrease the reference tone by pressing the STREAM/CENT button.

The Display will show 8/9/0/1/2/3/4/5/6/7 to indicate the reference tone from 438 to 447Hz.