An issue from now over 20 years ago

but go to just over 10 minutes into this video from Mr Bohan:





it is stated that "defunct" fm broadcasting system then at Edentubber in north County Louth (Ireland) interfered with landing system at Belfast.
If something is "defunct" surely it is no longer operating and powered down I would have thought??

How could powered down transmission equipment cause interference , or was this not the case ?? Or am I missing something?

Also there is a mixup here between two different stations to have used the name Kiss FM