During the day time hours, you can get WILM up to the Philly airport and then its signal fades fast, so there is a small part of Del. county or is that Chester county, back to the Del state line (the I-95 corridor between Philly and Wilmington) that could get WILM during the day. However, as their programming closely mirrored WPHT's prior to the changes to local talk at 1210, and with 1210's far superior signal, no one in that small piece of PA would have a real need to tune into WILM unless searching out a traffic report as they drove towards Wilmington and as WDEL's signal is far stronger there 1150 would probably get those PA listeners. You're right though, once the sun sets WILM gets no further north than around Silverside Rd and Rt. 202 in North Wilmington, so PA would be totally out of the question.
You're right those other Wilmington AM's just don't have enough signal to reach PA much less Philly. 1260 WNRK's signal did go up to Landenberg, PA clearly as their directional signal was aimed that way (which is why they didn't do very well in Wilmington ratings as the signal wouldn't make it to Downtown Wilm from Newark), so whatever PA county that is, 1260 could have shown up in their ratings, but that might not be in the Philly market. I believe WNRK only showed a couple of times in the Wilmington ratings, even in its glory days.
Good question about WBAL and Orioles and Ravens games. I know 1290 WWTX and sometimes WILM (if 1290 has some other sports event), carry Ravens football, but with their lousy signal into PA they probably won't ever show as WDEL does airing the Phillies.
