Do we have any readers in the Lansing MI or Evansville IN areas that can give 226.4 MHz a listen and see if it is still in use?
Based on some new information we have it looks like this frequency is being cleaned out of its FAA assignments. The latest to move is the Akron-Canton OH Regional A/D moved to 371.875 MHz. I know both Lansing and Evansville are listed in the latest IFR Sup but changes to that pub can sometimes be slow. At any rate expect 226.4 MHz to go dark at those two locations (if it hasn't already) very soon.
Feel free to contact me at my email address above.
Update: Joe Cobb over at BNA has confirmed that 226.4 MHz is being used by the Approach/Departure controllers in the Evansville, Indiana area. Now do we have anyone in the Lansing Michigan area that can confirm if this freq is still being used in that area?