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AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jun 30, 10:14 am, "Porgy Tirebiter" wrote:
- "Radium" is a well known "Troll". - When he runs low/out of meds and tin foil he will - post this techo-babble crap all over usenet. - Just add him to your killfile list. - "Radium" is a "Throw-away"....a complete waste of time...... PT - Then why waste your time replying to his posts ? IMHO - In another life "Radium" would have made a great High School Science Teacher : Who's Students when on to do great things with their lives : Because "Radium" Touched Them With A Thirst For Knowledge And A Quest For Answers. -but- These NewsGroups are NOT a High School Science Class -and- "Radium" is just being 'radium'. http://en.wikipedia.org/wiki/Radium -alas- Our "Radium's" Half-Life of Readable Interest http://en.wikipedia.org/wiki/Half-life is at best about 16.04 Seconds ~ RHF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In rec.radio.amateur.antenna Radium wrote:
On Jun 30, 3:32 am, "Mike Kaliski" wrote: It is not possible to modulate a carrier frequency at a frequency higher than the carrier frequency. Why not? I am getting conflicting answers. Some say it's possible to modulate a carrier frequency at a frequency higher than the carrier frequency, others say it isn't. Who is right? The defining equations, you blithering idtiot. Here they are for the last time: http://ccrma.stanford.edu/~jos/mdft/...lation_AM.html -- Jim Pennino Remove .spam.sux to reply. |
(OT) : Radium - In Another Life You Would Have Made A Great High School Science Teacher
RADIUM,
IMHO - In another life "Radium" you would have made a great High School Science Teacher : Who's Students when on to do great things with their lives : Because You "Radium" Touched Them With A Thirst For Knowledge And A Quest For Answers. -but- These NewsGroups are NOT a High School Science Class -and- "Radium" you are just being 'radium'. = http://en.wikipedia.org/wiki/Radium decaying into a gas and dispersing into nothingness. http://en.wikipedia.org/wiki/Radon -alas- "Radium" Your Half-Life of Readable Interest http://en.wikipedia.org/wiki/Half-life is at best about 16.04 Seconds ~ RHF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
RHF wrote:
... Because "Radium" Touched Them With A Thirst For Knowledge And A Quest For Answers. ... I don't know, according to any instructor I have ever had respect for: "There are NO stupid questions, only stupid people who are afraid to ask questions." Depends ... I guess. JS |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
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AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jun 30, 1:38 pm, Don Bowey wrote:
On 6/30/07 12:46 PM, in article . com, "Radium" wrote: On Jun 30, 3:32 am, "Mike Kaliski" wrote: It is not possible to modulate a carrier frequency at a frequency higher than the carrier frequency. Why not? I am getting conflicting answers. Some say it's possible to modulate a carrier frequency at a frequency higher than the carrier frequency, others say it isn't. Partly it's because you formulate **** poor questions. Who is right? Neither if stated as an "absolute rule," a.k.a. a Universal Generalization. It depends on what you want as a result. However, IMHO opinion, I believe it is best to have the Carrier at a higher frequency than the modulating frequency. If you are amplitude modulating a Carrier with a voice band signal, then it is mandatory, for a reasonable result, that the Carrier have a much higher frequency than the modulating frequency. If you are AM modulating (a.k.a. RF mixing or converting) two signals for the purpose of creating sum and difference "Carriers" in, for example, a synthesizer, you could use the low frequency to "modulate" the high frequency frequency, but I donšt recommend it unless some special effect is desired. Start with the question of what is it you wish to accomplish then ask real questions, not some far-out hypothetical drivel. . |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"Radium" wrote in message oups.com... On Jun 30, 3:32 am, "Mike Kaliski" wrote: It is not possible to modulate a carrier frequency at a frequency higher than the carrier frequency. Why not? I am getting conflicting answers. Some say it's possible to modulate a carrier frequency at a frequency higher than the carrier frequency, others say it isn't. Who is right? Radium Me Read my entire earlier reply. Then go to the library and spend several years reading through the electronics section with particular emphasis on the origins of electrical technology and early wireless. Then take a technical biased university course incorporating logic and critical analysis and all will become clear. Without a basic knowledge of the subject, you are unable to make any form of critical judgement as to the accuracy or correctness of what people are telling you and all your questions become valueless because you do not have the nous to evaluate the answers you receive. Start with the basics and then try working up from there. Many inadvisable things are technically possible, putting a dead short across the mains will generate a pretty good example of electromagnetic pulse, but it is far better to use a capacitive discharge circuit to do the same job. You could try modulating carriers at all different sorts of frequencies to generate harmonics, far better to use a square wave generator. You get the idea. Regards Mike G0ULI |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jun 30, 3:46 pm, Jeff Liebermann wrote:
With AM, it's ALWAYS the high frequency that acts as the carrier and the lower that acts as the modulation. In AM, isn't the carrier the signal which always maintains a constant frequency and only varies by amplitude? If a carrier signal varies by anything other than just amplitude, then it isn't AM. Right? |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Radium wrote:
... If a carrier signal varies by anything other than just amplitude, then it isn't AM. Right? Let logic be your guide, again. As was pointed out earlier, the voice freqs which modulate the carrier will cause a variance in freq (a small fm component.) In fm, it is not unusual for a small "amplitude modulation" to be generated, as the varying/spanning of freq(s) is caused by the modulation, some changes in fm carrier can be generated. In an imperfect world, nothing is "perfect." Regards, JS |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
Radium hath wroth:
On Jun 30, 3:46 pm, Jeff Liebermann wrote: With AM, it's ALWAYS the high frequency that acts as the carrier and the lower that acts as the modulation. In AM, isn't the carrier the signal which always maintains a constant frequency and only varies by amplitude? You really are clueless. The carrier does NOT vary in amplitude. If it did, that would be modulating the carrier, which is the job of the modulator, not whatever is producing the carrier. You could have two modulators in series, that would make the circuit overly complicated. Please re-read my highly simplified previous explanation about the symmetry of the AM multiplier (mixer) input ports until it's absorbed and understood by your porous brain. Incidentally, the reason I keep using the term "multiplier (mixer)" is to avoid confusion with a harmonic multiplier. An AM modulator is a mixer, not a harmonic multiplier. Also, the carrier might remain constant frequency, for a given FCC channel assignment, but the modulation is all over the place. For example, your voice goes from 300 to 3000Hz, all of which is fed to the modulator for digestion. Conventional TV is VSB (visidual side band) which is a form of AM with one of the two side bands partially removed, usually by filtering. There's a carrier 1.25MHz offset for the video, another carrier 4.5Mhz offset for the audio, and whatever else they can throw in for low speed data. Two more more carriers are required for TV+audio. If you want to get really high-techy, the new digital modes (DRM, iBiquity, HD Radio, etc) all have multiple carriers, each of which is modulated individually. Same with various OFDM modes, which have multiple carriers, individually modulated and positioned orthogonally from each other to prevent mutual interference from adjacent modulated carriers. If a carrier signal varies by anything other than just amplitude, then it isn't AM. Right? Wrong. The carrier can also vary, such as in a sweep generator or jammer. It's not commonly done but it's possible. Want to obliterate the entire AM broadcast band? No problem. Just sweep the carrier from 530KHz to 1650KHz, while modulating the 300 to 3000Hz audio with a rendition of your incoherent ranting. By the way, you're welcome. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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