Anchor Media is who once owned the remnants of WFAA-AM/FM (by then was called KLDD-AM and KZEW-FM.) They bought the duo from Belo in 1987.
The Northlake towers (WFAA/WBAP) even after the split were 3 total. As I recall the middle tower was also 820 while all three were 570. After the split which occurred 4/30/70, the problem was isolating the signals. 820 didn't effect 570 but 570 would bleed over to 820 until it was finally fixed. Inside the Northlake building (on the right when you walked in from the back dock) was a not so small room with equipment for isolating the signals so one tower (I think the middle one) could be used for both frequencies. It was a mess but they finally worked it out. There was no friction between Belo and Carter it was just that the Belo boys had a lot of time, money and energy to try out new ideas. Carter agreed to sharing the Northlake facility as a money saver until 820 was later moved. Anyone who ever toured the old Grapevine facility would never forget it. As someone might have mentioned there were four towers at the Grapevine plant, 1=820, 3=570.
KKDA's towers are probably still in their original place from 1957 when KBCS took the air as a Grand Prairie-only station (well, they touted the "Golden Triangle" of Grand Prairie, Arlington and Irving.) Then again, I just wandered across a note on my own site that says the first towers were on Beatty Rd, south of town.