Laurence Glavin said:
I'm getting a little tired about the use of the phrase "WBZ, heard in 38 states". There are many stations around the country operating on 1030, and it can no more be heard very far way from Boston than St. Louis's KMOX or Minn/St. Paul's WCCO.
WBZ was not the only Class IA clear channel AM that claimed to be heard in 38 states but it was the most easterly of the ones that did. Actually, it was the most easterly Class IA in the US and maybe Canada too--because CBA was almost certainly a IB. (Not only was it co-channel with KNX but there are a bunch of what were Class IIs on 1070 in the midwest and even one in Canada.) Almost certainly, WCAU (now WPHT) made a similar claim. Others that probably made such claims included WEAF (now WFAN), WABC, WCBS, WHAM, KDKA, WJR, WTAM, WLW, WHAS, WMAQ (now WSCR), WGN, WBBM, WLS, WSM, and KMOX. The trick was being located close enough to the northeast, where all of the states with small geographic areas are located. The station that claimed to serve the greatest population at night was WOR, which was a IB but had a directional pattern that concentrated its coverage along the eastern seaboard, still the county's most densely populated area. WOR claimed to reach 36 million people in 18 states at a time when the total US population was only about 130 million.
If you go by the FCC's current formulas for calculating nighttime skywave coverage, no US station could now claim to cover 38 states at night because no 50 kW ND Class A AM's 0.5 mV/m 50% skywave contour extends more than about 500 miles from its transmitter. The new formulas, which dramatically reduced the skywave coverage areas, went into effect in the early 80s, I believe. The new formulas were just as much responsible for reducing the claimed coverage areas as were all of the new full-time Class Bs AMs that were added on the former clear channels starting in the '80s. WBZ and WWL are directional, so their coverage extends a bit further than that of the ND Class As--but not 40% further, which is what you might predict based on field intensity at their pattern maxima.
But claiming to be HEARD IN 38 states is different from claiming to COVER (or even to SERVE) 38 states. If any AM stations still keep reception reports from DXers, there are probably hundreds of AMs, many not especially powerful, in the US and Canada that could claim to have been heard in 38 or more states.