Doug;
I've never found a "drill sharpener" that works very well.
These days I buy new or professionally resharpened aircraft drills on eBay and just throw them away when they get dull. If I use the right pressure, speed, and cutting lubricant, they last a long time before I toss them. I buy mostly the #30, 20, 10, and "F" sizes as well as a few other useful sizes. They usually come in a package of six to ten drills so it isn't often that I have to order more.
Regards, Neil Tucson, AZ