Broadcasters clamored for it and critics decried it, but six months after the FCC gave its approval for FM HD Radio stations to boost their digital carrier power by as much as 10dB, just less than 5 percent of the total number of those stations eligible have done so, based on an analysis recently published in the NAB's Radio Tech Check.

Tech Check notes that so far, 86 stations have filed notice of operation at elevated digital carrier levels. Of those, 37 percent have elected to boost power levels to something below -14dBc, while roughly 55 percent have filed the required notice for operation at -14dBc, and only six have requested increases to the maximum -10dBc.

According to the FCC CDBS database, 1,577 stations are now flagged as operating in FM hybrid digital, meaning only about 4.5 percent have notified the commission of any increase, and less than half of one percent have requested an increase to the maximum -10dBc.

Most industry observers seem to agree that stations posting increases were able to accommodate higher digital carrier levels without any significant modification to their facilities, and that the vast majority of digital FMs have adopted a wait-and-see attitude, pending higher receiver penetration numbers and improvement in station revenues.