dxAce wrote:
I wasn't aware that anyone was running IBOC overnight.

I was going to say "well, he was listening at 5:30am - and if he was
west of Thunder Bay then he'd have been on Central Time". The numbers
still don't work out for most stations:

Station October "FCC sunrise"
WABC 0500 CST
WCCO 0630 CST
WLW 0645 CST
WHAM 0530 CST
KFAB 0630 CST

(that WLW figure doesn't make sense, I think I made a typo somewhere.
Probably 0545 or 0600.)

So it would have been "daytime" at WABC & WHAM but not at any of the
other stations. I am making the rash assumption the unnamed station on
1110 was KFAB -- maybe it was WBT? (which probably would have indeed
been in "daytime")

We do occasionally observe major stations running IBOC at night. It
must be some kind of FCC-sanctioned test as it happens far too often to
be explained as technical errors at some of the country's
best-engineered stations. Usually that doesn't happen at this many
stations at the same time though.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com