"Toxic" wrote in message
news
Does it really require a significant amount of extra electricity to run
the HD encoders and modulators, or is it like turning off the illuminated
station callsign on the front of the building to save a couple pennies?
If dwindling listenership in broadcast media is any predictor, then it
may all be moot as more stations do major cost cutting and go dark.

From what I have been able to discern, the IBOC sidebands are actually
generated by a separate transmitter, then combined with the AM signal (much
as the AM video and FM audio were on analog television). Digital
transmission is fairly energy intensive.