Intermediate Frequency Exchange
From The RadioReference Wiki
Available in: BCD396XT BC346XT BCD436HP
To access: Hold and press Func then 4(Ifx). Press Hold to resume. (BCD346XT, BCD396XT] Hold and press Func then 7(IFX). Press Channel to resume (BCD436HP)
Changes the IF used for a selected frequency to help avoid image and other mixer-product interference on a frequency.