To select a channel on the ECB1750 page:
Click on the Wireless tab.
Click on the Configuration button.
Selecting "All" would set the channel to Auto.
If you want to select a specific channel, click on the "None" button and then select a channel you want to use. The button should be gray indicating that it has been selected. Click Save and then click on the "Changes" button on the upper right hand side of the user interface to Apply the changes.