I remember them well... First heard them with 5kW on a portable radio while visiting my sister in CT. Again with 15kW from home in WNY. Very clear, since there were no other stations on 1620 in those days. Have QSL certificated from both receptions.
I even met Dave once or twice at hamfests - selling parts! Wonder if that's how he financed the Big One?
America needs a sense of humor...