If dealing with radio presets, it is most useful to have a reference sheet handy, like maybe on your mission sheet on your kneeboard. And yes, the display on the radio stack will not change if you're using presets (I was confused about this too at one point!). What makes it even more confusing is when setting your own preset channels, it can be a bit odd sometimes as you don't get any "feedback" that you've done things correctly, until you try to contact someone on that preset.
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- Ice