[AMRadio] 29080

[Kim Elmore]

Yep, you're right, may bad: if the harmonic originates in the PA, 
then it will be as nicely modulated as the fundamental. If the 
harmonic is generated externally, then the audio is distorted.

Kim N5OP


At 09:22 PM 12/13/2011, you wrote:
> > I'm not sure I buy into the harmonic hypothesis because the side
> > bands are multiplied, too. When that happens the recovered audio will
> > be very distorted. Jim reported that he thought the audio sounded
> > pretty good, so I doubt that he was hearing harmonics.
>
>It depends if the harmonic generation takes place before or after
>modulation. If after modulation, there will be severe distortion.
>
>But, say you have a plate-modulated class C amplifier, and the 2nd
>harmonic (for example) is not adequately filtered. The modulator will
>happily modulated both the fundamental and 2nd harmonic, and no distortion
>will be present on the harmonic. I have heard 2nd harmonics of AMBC
>stations sound FB. In this case the harmonic generation is "before
>modulation."
>
>73,
>-Larry/NE1S
>
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