Most folks add 2 variable knobs to adjust the echo. Looking at the back they mount them in the upper left corner of the back. This vid might help.
how do you like the 2980? still treating you good?RCI 2980 is is now my base station radio. It's a very nice radio.
I will need to upgrade the meter lights with some white LED. Transmits and receives very good. Best radio I have ever owned!