Why? Their HD signals are interfering with their own analog signals cross-country on WABC NYC and WJR Detroit-and they’re getting listener complaints-more in some markets than others. Citadel VP/Engineering Martin Stabbert tells RBR the move is temporary to tweak the HD engineering with iBiquity Digital.
We noticed a problem weeks ago (9/21/07 RBR #185). See "HD Radio 2007."
Stabbert tells RBR: "When we turned on the nighttime HD in September we wanted to gather some signal and interference data to see where we were at with nighttime HD. Now we’re going to take a step back and make a few adjustments to minimize interference. It’s an ongoing process, just like any other broadcaster who has turned on HD at night."
Remember, at night, the HD signals will travel as far as the analog with skywave reception. So that HD-to-analog interference goes along with it-for a thousand miles give or take a few hundred. The FCC began allowing AM stations to broadcast in HD after dark on 9/14. Citadel will keep HD on during the day.
RBR observation: It may be just radio DX’ers complaining about reception. In many far-outlying areas the groundwave from WABC, for example, fights with the skywave already at night, so any added noise on the WABC analog there would be problematic for sure for areas like Poughkeepsie and Atlantic City. For most in-market listeners, the problem was likely minimal.