I am not sure if this is already well know, but it appears that WABC 770 kHz in New York is experiencing some transmitter issues as viewed on this overnight spectrum waterfall capture of 770 kHz (50 Hz bandwidth) over the evening of July 7/8 2014:
While monitoring their signal, there is a distinctive audible ‘crack’ sound heard each time the carrier makes the jump.
Full-data card in 175 days for English language report, SASE and souvenir postcard, v/s Robert N. Ward, Acting Officer-in-Charge.
Saint John MCTS
Canadian Coast Guard Base
P.O. Box 700
Saint John, NB E2L 4B3
Full-data QSL card in 18 days for English language report, souvenir postcard, mint stamps, address label and envelope, v/s unreadable, Station Manager. This was for my third report, the previous two returned due to incorrect address.
Iceland Telecom Ltd,
Gufunes Telecommunications Centre