OK, now that NTSC video is gone, so are my handy local video carriers that I used to use to check the frequency accuracy of my signal generators. However, I understand that there are pilot carriers buried within the 8VSB DTV signals that can be used for the same purpose. A couple of Google searches revealed that DTV ch. 7 is supposed to have a pilot at 174.310 MHz. Putting my old FM-10 on 174.310 & listening to the beat signal on my R-100, I heard a heterodyne of ~500 Hz. I thought that error was a bit high, so checked a few other DTV pilots (186.310 & 198.310). Interestingly, they were off by the same amount. I moved the FM-10 to 15 MHz & checked it against WWVH; heterodyne was ~1.5 Hz, equating to ~18 Hz @ 180 MHz, not ~500 Hz. My best guess is that the ATSC pilots are actually 309.450 kHz above the bottom of each channel, and the 310 kHz reference is an approximation.
Can anyone confirm the above? Bob NO6B
