I do enjoy air monitoring when I visit my parents in Omaha, NE, especially since Omaha PD and FD went APCO-25. I take one of my Bearcat 780's with me to Omaha whenever I go to visit. The very first time I went there I also took along the preamp. The radio is programmed with Chicago Center, Kansas City Center, Eppley Airport and Offut AFB frequencies. That first time in Omaha I plugged in the preamp, turned everything on, and the radio front end overloaded. Turned off the preamp and heard both sides of the conversations from both Chicago and Kansas City, with just the back-of-set antenna! Gotta love the flat midwest!
I was born/raised in Omaha, and at one point, lived underneath the right base entry for the 14s. Eventually we moved out to near KMLE, which is a nice little Class D field. I also went to Univ. of Nebraska at Omaha. but looking back on things now, I see the irony of it all; I had nothing to do with aviation/ATC at all when I was there, and instead studied Comp. Sci. I move to Las Vegas, get hit by the ATC/flying bug, and then see that one of the best places I could have gone to get into it, was UNO.. Classic case of "if I knew then what I know now..."
If you're getting that strong a signal when you're there, you should be able to pick up KLNK, KSUX, KDSM, the ZMP sectors that overly them, and the Columbus FSS.
Let me know when you head back there! If I'm there, I have some friends at R90, so I could arrange a tour of the TRACON.