Is it possible to type in macron (e.g. "ā") without using U.S. Extended Keyboard?

Solution 1:

Keep US Extended and use it to type your å. It's alt + k and then a.

Solution 2:

This is just a option without changing the default Keyboard.

In OS X, this can be accomplished by holding down the A briefly and a pop-up will appear.

Select diacritic

Just select by clicking or typing the corresponding number. In this case 8

ā ← Like that

The repeat delay can be set to prevent eeeeeeeeee from happening too quickly.

Keyboard settings