Sunday, September 23, 2007

Editorial on the recent approval of HD Radio (IBOC) in the USA

On Thursday the 22nd of March, 2007 the Federal Communications Commission approved all facets of digital broadcasting in the USA. In particular, AM stations will soon be authorized to begin 24/7 use of their first adjacent frequencies for digital sidebands.

What this does is open the door to significant interference to all AM stations. A 50kw clear channel station can run a digital transmitter at far more power than would be authorized for any conventional station in that location on those two adjacent frequencies. It will be interesting from a rather perverse sense to see what happens at night..

I have had two HD Radios, and found that the digital signals are very fragile, and cover about half the radius (1/4 the area) of a good analog signal. Electrical noise from many sources like car ignition, light dimmers and bad wiring can easily disrupt things.