Talk:Indian-head test pattern

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==== The reference needed for mentions of "sine wave tone" exists in Wikipedia under Audio, but it doesn't mention "sine wave tone" in particular as part of the test conducted with the test pattern, and that page needs an edit to add that information. ALL analog audio is sine wave; this particular tone spoken of here is 60 Hz which is calibrated with the specifications of the AC power supplied by electric power plants--also federally regulated to be exactly 60 Hz. It's upon that 60Hz calibration that other frequencies used in the broadcast depended on. Also true in radio broadcasting especially when going on emergency power during a power outage. If that 60Hz frequency reference was off, all the others would be as well. — Preceding unsigned comment added by DSLevesque (talk • contribs) 03:48, 5 April 2020 (UTC)