Not sure why yet. No radio tower has had an antenna at all in my decayed nature world.

edit
Ah, it's intentional? RadioTowerLot.java, line 112, it skips antenna/ladder placement if it's decayed buildings. I think that shouldn't be the case...

I think I was just in a rush and did that as a shortcut. I will take a look at it

should work better now... actually it has been working for while... I just forgot to mention and close this