Greyeagle...that radio is based on the JR662, so I pulled out my old 662 manual and what do you know -- same thing...
Step 6 of setting the EXPO says "Press the INCREASE or DECREASE buttons to increase/decrease the exponential value.
Step 7 of that section then says "Press the SCROLL button to access the Sub-Trim function.
Step 8 is "To exit, press the SCROLL and INCREASE buttons simultaneously.
No, there is no hidden reason for doing so...if you still have your manual and take a look at the page showing the Function Mode windows, you'll see that the radio will step through the menu functions in this order:
and so forth.
What the individual programming steps are telling is that you program the feature you're looking for (Expo, in your case). If you get done with the EXPO stuff, if you bump the SCROLL button, it simply takes you to the NEXT menu in sequence so you can set that feature up.
If you are done with programming the EXPO, you have two choices...the SCROLL button to go onto the next menu (Sub-Trim in this case), or you're done and exit out to the "normal" screen by hitting BOTH buttons at the same time.
NO magic involved, just stepping you through the various menus in order, one at a time.
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