Has anyone else noticed WBZ's unlistenable signal

[Mark Laurence]

If I have WBZ tuned in slightly off center on my cheap clock radio, I hear them switch over at 9 AM.  The signal turns to nearly pure white noise.  

Mark

-----Original Message-----
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>

The IBOC sidebands are transmitted in quadrature, so it's invisible to
envelope detectors.  Only people with synchronous detectors hear it.