from the Never-Twice-the-Same-Color dept.
A long while back, the FCC set a hard deadline of July 13th, 2021, for shutting down the last NTSC television transmitters and transitioning channels to being digital fully. The other day, the last of the NTSC transmitters were shut down with hardly anyone commenting, except Hackaday which noted:
A significant event in the history of technology happened yesterday, and it passed so quietly that we almost missed it. The last few remaining NTSC transmitters in the USA finally came off air, marking the end of over seven decades of continuous 525-line American analogue TV broadcasts. We've previously reported on the output of these channels, largely the so-called "FrankenFM" stations left over after the 2009 digital switchover whose sound carrier lay at the bottom of the FM dial as radio stations, and noted their impending demise. We've even reported on some of the intricacies of the NTSC system, but we've never taken a look at what will replace these last few FrankenFM stations.
NTSC has been the analog protocol used in the US for television since 1941, initially for black and white and then by 1953 / 1951 for color. NTSC was sent at a 3:4 aspect ratio with 525 lines per frame at 30 frames per second. PAL and SECAM were the other two analog standards and used in other parts of the world. Four competing standards for digital signals are in use so far. They are DVB-T, ATSC, ISDB-T, and DTMB. The US uses ATSC.
The US has been among the last countries to switch over to digital television transmissions. The FCC gave stations lots of lead time, several extensions, and multiple exit strategies, including the choice of shutting down the channel and ceasing operations permanently.