I appreciate the replies. It's too bad that they've discontinued the Sangean HDT-1X. Perhaps, I could find it on Ebay or elsewhere.
I did check with both the manufacturer, Yamaha, as well as Crutchfield. Neither one of them had any HD tuners compatible with my A/V receiver. In fact, the rep at Yamaha seemed surprised that I would even ask such a question. I am beginning to conclude that there is very little demand for these tuners.
Perhaps, the easiest way of doing it is hooking up a car model, such as the Visteon. It's too bad this technology has not been promoted in home theatre systems. And to get an A/V receiver with a built-in tuner costs a fortune, just for this one extra feature.