[ARC5] Harmonic question

[AKLDGUY .]

> If the harmonics are generated by the final amplifier of a plate
modulated AM transmitter then it should sound as normal > with a small
exception. If the RF on the  final amplifier's plate has the same waveform
thru out the audio cycle then the
> harmonics will be equally modulated and the signals received at harmonic
related frequencies will sound normal.
>
> However, the amplifier plate may not exhibit the same wave form as the
plate voltage is changed, in that case there will > be some audio
distortion.

Seems a reasonable explanation.

 > If the harmonics are produced by something after the modulation process,
such as diode in a RF power meter,...

No, the question asked was not about frequency multiplying, only the normal
harmonics unavoidably produced
in a MOPA transmitter.

73 de Neil ZL1ANM


On Sun, Apr 16, 2017 at 2:33 PM, Fuqua, Bill L <wlfuqu00 at uky.edu> wrote:

>
>   It depends on the source of the harmonics.
>
> If the harmonics are generated by the final amplifier of a plate modulated
> AM transmitter then it should sound as normal with a small exception. If
> the RF on the  final amplifier's plate has the same waveform thru out the
> audio cycle then the harmonics will be equally modulated and the signals
> received at harmonic related frequencies will sound normal.
>
>    However, the amplifier plate may not exhibit the same wave form as the
> plate voltage is changed, in that case there will be some audio distortion.
>
>    If the harmonics are produced by something after the modulation
> process, such as diode in a RF power meter, then the Carrier and sidebands
> will be multiplied by the harmonic number thus producing higher order
> sidebands on along with the normal ones. Lots of distortion.
>
>   There have been cheap 6 and 2 meter AM transmitters where the final is
> an amplitude modulated doubler.
>
> Look at the Harvey Wells Bandmaster. On 2 meters the final functions as a
> doubler.
>
> 73
>
> Bill wa4lav
>
>
>
> ------------------------------
> *From:* ARC5 <arc5-bounces at mailman.qth.net> on behalf of AKLDGUY . <
> neilb0627 at gmail.com>
> *Sent:* Saturday, April 15, 2017 9:52 PM
> *To:* ARC-5 List; milsurplus
> *Subject:* [ARC5] Harmonic question
>
> Suppose I have a properly adjusted AM transmitter and am operating it.
>
> What would a nearby listener hear at say, the third or fifth harmonic,
> assuming a good strength carrier at that frequency is present at his
> receiver?
>
> Is the bandwidth of the sidebands 3x or 5x, so all that's heard is
> incomprehensible splatter?
>
> This is not a trick question. The textbooks don't address this at all.
>
> 73 de Neil ZL1ANM
>
>
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