From today's TRI Newsletter: The NAB’s FASTROAD engineering project says the early results of the “single frequency network field tests” in the Baltimore area are “very encouraging.” They worked with an experimental main station and a booster site, and monitored potential interference with existing analog signals. Results? “iBiquity’s synchronized SFN booster technology has the potential to not only extend an FM station’s HD Radio signal coverage to the protected contour, but also fill in areas of compromised signal.” Coverage – even with the FCC loosening the wraps a little on the original 1% of analog power levels – is one of the ongoing issues with HD Radio. These boosters would help out by re-broadcasting the digital signal. The test had the main IBOC (in-band on-channel) transmitter near Catonsville in the southwest corner of Baltimore. The booster is in Perry Hall, northeast of Baltimore. One of the things they tweaked was the power level of the booster, so as not to “overload” it where the overlap occurred with the main transmitter. Another thing they checked – the booster’s effect on the analog signal. Some interesting technical challenges – and opportunities – ahead for HD Radio in 2011. Read the NAB report here.