Érdemes elgondolkozni rajta.
Ugyanakkor van egy kérdésem: volt alsó frekvenciahatás az AM adásokban?
"NRSC-1, published in July 1998, embraced the age old challenge of high frequency audio quality in AM broadcasting. A modified 75 u/sec preemphasis/deemphasis curve was recommended, much like the long used system used in FM exciter and receiver designs. In addition, the standard recommended limiting audio bandwidth to 10 Khz (-30db @ 10.5 Khz., -40db @ 11.0 Khz., -50db @ 15. Khz.). This "audio masking" scheme reduced percentage of modulation at 15 Khz. down to as little as .32 percent. This produced substantially less 2nd adjacent channel sideband interference in wideband receivers..." [link]
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