HD is not yet authorized for night operation, although 4:30 AM falls in the
experimental period, so they could be testing.

WABC-77 AM (along with WOR-710 and WFAN-66 AM) shuts down the IBOC down
for the night.

WCBS-88 AM, however is running it 24/7. I guess they're experimenting
interference with WLS-89 AM,Chicago?

WNYC-82 AM was running IBOC day and night for the past month (10,000
watts day, 1000 watts night). The exciter has been off since this past
Friday night, however. As of this morning, it was still shut off.

WADO-1280 AM's exciter has also been off over the weekend. I don't
know what happened this morning, though. Didn't tune in.

On a number of occasions, stations have run their IBOC all night. In
most cases this seems to involve major stations operated by major groups
such as Clear Channel. As much as some people may dislike Clear
Channel, they are not known for violating FCC technical regulations. [0]
I suppose in one or two cases there's been a simple mistake or failure
of a timer, but I have to think in most cases these stations have some
kind of temporary authority from the FCC for testing purposes.

(in most cases I've heard of, the IBOC is staying on *all night* -
including between sunset and midnight - not just during the experimental
period when it might arguably be legal without STA)

Salem Broadcasting (WMCA-57 and WWDJ-97 AM) are holding off on IBOC for
now....

Indeed, Salem reportedly *removed* IBOC from WIND-560 Chicago when they
acquired it from a different owner.

--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

[0] some would argue they get the interference-causing technology
declared legal before they try using itgrin, kinda