Jeffrey Fritz <jnfritz07@...>
Robert is generally correct about the "Graveyard" nighttime power limit increase to 1 KW. (Thanks for correcting my correction, Robert!) FCC rule changes did indeed raise the nighttime power limit to 1,000 watts for most, but not all Class C (formerly Class IV) stations.
This isn't completely across the board as there are exceptions for some Class C stations. To quote FCC § 73.182 - Engineering standards of allocation (Revised as of October 1, 2010):
"...stations under § 73.26(b) shall not be authorized to increase power to levels that would increase the nighttime interference-free limit of co-channel Class C stations in the conterminous United States... Such stations are normally protected to the daytime 0.5 mV/m contour. On local channels the separation required for the daytime protection shall also determine the nighttime separation...The actual nighttime (power) limitation will be calculated. For nighttime protection purposes, Class C stations in the 48 contiguous United States may assume that stations in Alaska, Puerto Rico, and the U.S. Virgin Islands operating on 1230, 1240, 1340, 1400, 1450, and 1490 kHz are Class C stations."
Thanks again, Robert!