As I recall, nothing (which is kinda my point). He hesitated for a moment and then said “this frequency”. Had he said “contact Ft Wayne Approach on this frequency” I wouldn’t have even posted this story.
Once, on an approach into Toledo. I was told to contact Tower on 118.1. I switched over and no one answered. I tried several times and nothing. I switched back to approach and let them know I was on final and could not contact the tower on 118.1 they told me to contact ground on 121.9. I called ground and they cleared me to land. The worst part of it all, this was during my IFR check ride!
“Clarence, Cezna 1234, vfr ff to podunk, one thousand five hundred, no sids, definitely no starz, over”
Sometimes the same guy is working all the frequencies. I was flying near Ashville, NC one night. And it was obvious that the same person was working App, Dep, Tower, Ground, and Clearance Delivery.
Wow! He prolly had to load the vending machine in hall when it got quiet. Seriously, some of them controllers are amazing at what they can juggle ...