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AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 7/2/07 11:00 AM, in article , "John Smith"
wrote: John Smith wrote: [stuff] And, by the way, when using plate modulation on a transmitter, the DC input to plates of the transmitter has a modulated signal impressed upon it by a modulation transformer (simply an audio transformer), every watt of power to the xmitter is so impressed ... The DC voltage/current to the xmitter contains the voice data--indeed, the exact same data which is impressed onto the DC on a telephone line (voice/modulation.) However, the real importance of this will only become clear to you when you come out from under the influence of whatever it is you are smokin' ... JS But I know WHY the plate modulated rig creates sidebands, and you still don't, because you refuse to learn. |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Don Bowey wrote:
But I know WHY the plate modulated rig creates sidebands, and you still don't, because you refuse to learn. Interesting, now you attempt to divert the conversation into the modulation having been, FINALLY, impressed into the sidebands ... Hell, it was just such a chore bringing your education up to speed on this one point, I'd have to be paid to continue your education! JS |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 7/2/07 11:53 AM, in article , "John Smith"
wrote: Don Bowey wrote: But I know WHY the plate modulated rig creates sidebands, and you still don't, because you refuse to learn. Interesting, now you attempt to divert the conversation into the modulation having been, FINALLY, impressed into the sidebands ... Hell, it was just such a chore bringing your education up to speed on this one point, I'd have to be paid to continue your education! JS You allude to knowing how the sidebands come into being yet you cannot provide any clue that you really understand AM, and you continue to think microphone current in a telephone loop is the same thing. You're as FOS as they come. I doubt you have fooled anyone on this board with your attempts to look like you know more than you really do. |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Don Bowey wrote:
You allude to knowing how the sidebands come into being yet you cannot provide any clue that you really understand AM, and you continue to think microphone current in a telephone loop is the same thing. You're as FOS as they come. I doubt you have fooled anyone on this board with your attempts to look like you know more than you really do. Buddy, you speak about these people being "fooled", interesting term, implying you consider them fools! I doubt that is true, they have seen through you in a heartbeat, most, probably long before now ... I imagine they are just embarrassed for you--having made such an A$$ of yourself ... JS |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 7/2/07 12:29 PM, in article , "John Smith"
wrote: Don Bowey wrote: You allude to knowing how the sidebands come into being yet you cannot provide any clue that you really understand AM, and you continue to think microphone current in a telephone loop is the same thing. You're as FOS as they come. I doubt you have fooled anyone Please point out, above, or wherever you wish, where I said they were fooled. You can't you POS liar. Buddy, you speak about these people being "fooled", interesting term, implying you consider them fools! on this board with your attempts to look like you know more than you really do. I doubt that is true, they have seen through you in a heartbeat, most, probably long before now ... I imagine they are just embarrassed for you--having made such an A$$ of yourself ... JS While you continue to allude to skills and knowledge you don't have. Do you often get away with this useless chest beating? |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Don Bowey wrote:
... While you continue to allude to skills and knowledge you don't have. Do you often get away with this useless chest beating? You pathetically petty idiot ... I guess you call names because of your age. Or, others have called you names and it has hurt your ego. Get an education, grow-up and get off the drugs--you will be able to finally respect yourself! :-( Best hope in your therapy! JS |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 7/2/07 2:12 PM, in article , "John Smith"
wrote: Don Bowey wrote: ... While you continue to allude to skills and knowledge you don't have. Do you often get away with this useless chest beating? You pathetically petty idiot ... I guess you call names because of your age. Or, others have called you names and it has hurt your ego. Get an education, grow-up and get off the drugs--you will be able to finally respect yourself! :-( Best hope in your therapy! JS But POS was intended for guys like you. Ok! Again, you win. Please enjoy your blissful ignorance with my good wishes. Finis |
snip, Snip. SNIP ! the "Rec.Radio.Shortwave" Group from the Newsgroups {Distribution} Header - please, Please. PLEASE !
On Jul 2, 6:16 am, Don Bowey wrote:
On 7/1/07 10:06 PM, in article , "Telamon" wrote: In article , cledus wrote: Snip Would you please have the decency to snip rec.radio.shortwave and other groups from the newsgroup header. Thanks. - Would you please come and ask nicely. - I don't like how you put your order. don bowey, Don Bowey. DON BOWEY ! Oh Please with Sugar and Spice and Everything Nice snip, Snip. SNIP ! the "Rec.Radio.Shortwave" Group from the Newsgroups {Distribution} Header when you Post your Reply - It would be ever so decent of you Kind and Wonder Sir. ;-) thank you very much - most respectfully ~ RHF |
snip, Snip. SNIP ! the"Rec.Radio.Shortwave" Group from the New...
y'all forgot about something,,,,
Time does not exist. cuhulin |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
" wrote in message ... Better still, Vestigial Sideband! You're both wrong. It is VIRTUAL SIDEBAND Nope - VSB, as commonly used in broadcast television, most definitely stands for "vestigial sideband" - a form of AM in which the carrier and part of one sideband (in this case, the lower sideband is the "vestigial" one) are retained, along with one full sideband which carries the information (in this case, the upper sideband, which carries the luminance (Y) video information). Bob M. |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In article ,
Don Bowey wrote: On 7/1/07 10:06 PM, in article , "Telamon" wrote: In article , cledus wrote: Snip Would you please have the decency to snip rec.radio.shortwave and other groups from the newsgroup header. Thanks. Would you please come and ask nicely. I don't like how you put your order. This is a stupid cross posted Troll thread so pretty please with sugar on it snip the other news groups it does not originate from. Thank you very, very much in advance. -- Telamon Ventura, California |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jul 2, 9:09 pm, Telamon
wrote: In article , Don Bowey wrote: On 7/1/07 10:06 PM, in article , "Telamon" wrote: In article , cledus wrote: Snip Would you please have the decency to snip rec.radio.shortwave and other groups from the newsgroup header. Thanks. Would you please come and ask nicely. I don't like how you put your order. This is a stupid cross posted Troll thread so pretty please with sugar on it snip the other news groups it does not originate from. Thank you very, very much in advance. -- Telamon Ventura, California Bravo ! ;o} ~ RHF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Ron Baker, Pluralitas! wrote:
"John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? What would it look like on a spectrum analyzer? Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? What would that look like on a spectrum analyzer? |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Don Bowey wrote:
On 7/2/07 12:29 PM, in article , "John Smith" wrote: Don Bowey wrote: You allude to knowing how the sidebands come into being yet you cannot provide any clue that you really understand AM, and you continue to think microphone current in a telephone loop is the same thing. You're as FOS as they come. I doubt you have fooled anyone Please point out, above, or wherever you wish, where I said they were fooled. You can't you POS liar. Buddy, you speak about these people being "fooled", interesting term, implying you consider them fools! on this board with your attempts to look like you know more than you really do. I doubt that is true, they have seen through you in a heartbeat, most, probably long before now ... I imagine they are just embarrassed for you--having made such an A$$ of yourself ... JS While you continue to allude to skills and knowledge you don't have. Do you often get away with this useless chest beating? |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency
Don Bowey wrote:
On 7/2/07 2:12 PM, in article , "John Smith" wrote: Don Bowey wrote: ... While you continue to allude to skills and knowledge you don't have. Do you often get away with this useless chest beating? You pathetically petty idiot ... I guess you call names because of your age. Or, others have called you names and it has hurt your ego. Get an education, grow-up and get off the drugs--you will be able to finally respect yourself! :-( Best hope in your therapy! JS But POS was intended for guys like you. Ok! Again, you win. Please enjoy your blissful ignorance with my good wishes. Finis |
snip, Snip. SNIP ! the "Rec.Radio.Shortwave" Group from the Newsgroups {Distribution} Header - please, Please. PLEASE !
On Mon, 02 Jul 2007 14:42:49 -0700, RHF
wrote: On Jul 2, 6:16 am, Don Bowey wrote: On 7/1/07 10:06 PM, in article , "Telamon" wrote: In article , cledus wrote: Snip Would you please have the decency to snip rec.radio.shortwave and other groups from the newsgroup header. Thanks. - Would you please come and ask nicely. - I don't like how you put your order. don bowey, Don Bowey. DON BOWEY ! Oh Please with Sugar and Spice and Everything Nice snip, Snip. SNIP ! the "Rec.Radio.Shortwave" Group from the Newsgroups {Distribution} Header when you Post your Reply - It would be ever so decent of you Kind and Wonder Sir. ;-) thank you very much - most respectfully ~ RHF --- Seems to me his posts are on topic for rrs, so why don't you just learn how to use a filter? -- JF |
snip, Snip. SNIP ! the"Rec.Radio.Shortwave" Group from the New...
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AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!"
wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? --- LTSPICE circuit list: Version 4 SHEET 1 1672 1576 WIRE 32 880 -256 880 WIRE 192 880 32 880 WIRE 528 912 336 912 WIRE 192 944 -112 944 WIRE -256 992 -256 880 WIRE -112 992 -112 944 WIRE -256 1120 -256 1072 WIRE -112 1120 -112 1072 WIRE -112 1120 -256 1120 WIRE -256 1168 -256 1120 FLAG -256 1168 0 FLAG 32 880 in SYMBOL SPECIALFUNCTIONS\\MODULATE 192 880 R0 WINDOW 0 37 -55 Left 0 WINDOW 3 55 119 Center 0 SYMATTR InstName A1 SYMATTR Value mark=1e6 space=1e6 SYMBOL voltage -256 976 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 10 SYMBOL voltage -112 976 R0 WINDOW 3 24 160 Left 0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value SINE(.5 .5 1e5) SYMATTR Value2 AC 1 TEXT -96 1240 Left 0 !.tran 5e-5 TEXT -96 1208 Left 0 !.params w0=2*pi*1K Q=5 --- What would it look like on a spectrum analyzer? --- | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz --- Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? --- LTSPICE circuit list: Version 4 SHEET 1 880 680 WIRE 240 64 176 64 WIRE 432 64 320 64 WIRE 352 144 224 144 WIRE 352 160 352 144 WIRE 16 176 -208 176 WIRE 160 176 96 176 WIRE 176 176 176 64 WIRE 176 176 160 176 WIRE 320 176 176 176 WIRE 432 192 432 64 WIRE 432 192 384 192 WIRE 320 208 288 208 WIRE 288 256 288 208 WIRE 16 288 -48 288 WIRE 160 288 160 176 WIRE 160 288 96 288 WIRE 224 320 224 144 WIRE 352 320 352 224 WIRE -208 336 -208 176 WIRE -48 336 -48 288 WIRE -208 448 -208 416 WIRE -48 448 -48 416 WIRE -48 448 -208 448 WIRE 224 448 224 400 WIRE 224 448 -48 448 WIRE 352 448 352 400 WIRE 352 448 224 448 WIRE -208 496 -208 448 FLAG -208 496 0 FLAG 288 256 0 SYMBOL voltage -208 320 R0 WINDOW 0 -42 5 Left 0 WINDOW 3 24 104 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value SINE(0 .1 1.1e6) SYMBOL res 112 160 R90 WINDOW 0 -33 56 VBottom 0 WINDOW 3 -31 61 VTop 0 SYMATTR InstName R1 SYMATTR Value 1000 SYMBOL voltage -48 320 R0 WINDOW 0 -39 4 Left 0 WINDOW 3 24 104 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value SINE(0 .1 .9e6) SYMBOL res 112 272 R90 WINDOW 0 -38 56 VBottom 0 WINDOW 3 -31 59 VTop 0 SYMATTR InstName R2 SYMATTR Value 1000 SYMBOL res 336 48 R90 WINDOW 0 -36 59 VBottom 0 WINDOW 3 -36 61 VTop 0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL voltage 352 416 R180 WINDOW 0 14 106 Left 0 WINDOW 3 24 104 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 12 SYMBOL voltage 224 304 R0 WINDOW 0 -44 4 Left 0 WINDOW 3 24 104 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 12 SYMBOL Opamps\\UniversalOpamp 352 192 R0 SYMATTR InstName U2 TEXT -252 520 Left 0 !.tran 3e-5 Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. --- What would that look like on a spectrum analyzer? --- | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jul 3, 12:50 pm, John Fields wrote:
On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ....Keith |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jul 3, 2:07 pm, Keith Dysart wrote:
On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. And the amplitudes of the the sum and difference frequencies need to be one half of the amplitude of the frequencies being multiplied. ....Keith |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Tue, 03 Jul 2007 12:05:52 -0700, Keith Dysart
wrote: On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. --- That's right. They can't possibly be because the first instance _was_ multiplication and the second instance addition. --- The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. --- That makes no sense since the frequencies are different and, consequently, the phase difference between the signals will be constantly changing. -- JF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Jul 3, 4:19 pm, John Fields wrote:
On Tue, 03 Jul 2007 12:05:52 -0700, Keith Dysart wrote: On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. --- That's right. They can't possibly be because the first instance _was_ multiplication and the second instance addition. Quite counter intuitive, I agree, but none-the-less true. To convince myself, I once created an Excel spreadsheet to demonstrate the fact. It along with some other discussion and plots are available here http://keith.dysart.googlepages.com/radio5 The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. --- That makes no sense since the frequencies are different and, consequently, the phase difference between the signals will be constantly changing. To get exactly the same results, if, at time t0, the phases for the signals being multiplied together are 0, then at time t0, the initial phases for the signals being added must be 90 and -90. ....Keith |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Tue, 03 Jul 2007 15:02:59 -0700, Keith Dysart
wrote: On Jul 3, 4:19 pm, John Fields wrote: On Tue, 03 Jul 2007 12:05:52 -0700, Keith Dysart wrote: On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. --- That's right. They can't possibly be because the first instance _was_ multiplication and the second instance addition. Quite counter intuitive, I agree, but none-the-less true. To convince myself, I once created an Excel spreadsheet to demonstrate the fact. It along with some other discussion and plots are available here http://keith.dysart.googlepages.com/radio5 The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. --- That makes no sense since the frequencies are different and, consequently, the phase difference between the signals will be constantly changing. To get exactly the same results, if, at time t0, the phases for the signals being multiplied together are 0, then at time t0, the initial phases for the signals being added must be 90 and -90. --- OK, but that's just for the single slice in time where the circuit reactances for both frequencies are complex conjugates, and cancel, leaving only pure resistance for both signals to drive at that instant. -- JF |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Mon, 2 Jul 2007 17:08:43 -0600, "Bob Myers"
wrote: " wrote in message ... Better still, Vestigial Sideband! You're both wrong. It is VIRTUAL SIDEBAND Nope - VSB, as commonly used in broadcast television, most definitely stands for "vestigial sideband" - a form of AM in which the carrier and part of one sideband (in this case, the lower sideband is the "vestigial" one) are retained, along with one full sideband which carries the information (in this case, the upper sideband, which carries the luminance (Y) video information). Bob M. It is definitely vestigial side band. There is a bandpass filter in transmitter to get rid of much of it when the signal is generated, and generally a tuned coaxial stub on the antenna to get rid most of the rest of it. Effectively NTSC television is single sideband with carrrier (while SSB is technicall SSBSC, Single Side Band, Supressed Carrier, which is considerably more difficult to generate and detect). |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In article ,
John Fields wrote: On Tue, 03 Jul 2007 12:05:52 -0700, Keith Dysart wrote: On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. --- That's right. They can't possibly be because the first instance _was_ multiplication and the second instance addition. --- The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. --- That makes no sense since the frequencies are different and, consequently, the phase difference between the signals will be constantly changing. After you get done talking about modulation and sidebands, somebody might want to take a stab at explaining why, if you tune a receiver to the second harmonic (or any other harmonic) of a modulated carrier (AM or FM; makes no difference), the audio comes out sounding exactly as it does if you tune to the fundamental? That is, while the second harmonic of the carrier is twice the frequency of the fundamental, the sidebands of the second harmonic are *not* located at twice the frequencies of the sidebands of the fundamental, but rather precisely as far from the second harmonic of the carrier as they are from the fundamental. Isaac |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"isw" wrote in message ... After you get done talking about modulation and sidebands, somebody might want to take a stab at explaining why, if you tune a receiver to the second harmonic (or any other harmonic) of a modulated carrier (AM or FM; makes no difference), the audio comes out sounding exactly as it does if you tune to the fundamental? That is, while the second harmonic of the carrier is twice the frequency of the fundamental, the sidebands of the second harmonic are *not* located at twice the frequencies of the sidebands of the fundamental, but rather precisely as far from the second harmonic of the carrier as they are from the fundamental. Isaac I can't speak to second harmonics of a received signal, though I can't think why they would be any different than an internal signal.. but: When you frequency multiply and FM signal in a transmitter (As used to be done on most FM transmitters in the days before PLL came along), you not only multiplied the extant frequency, but the modulation swing as well. i.e. if you start with a 1 MHz FM modualated crystal oscillator, and manage to get 500 Hz swing from the crystal (using this only as a simple example), then if you double that signal's carrier frequency, you also double the FM swing to 1 KHz. Tripling it from there would give you a 6 MHz carrier with a 3 KHz swing, and so on. |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"Keith Dysart" wrote in message ps.com... On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. And the amplitudes of the the sum and difference frequencies need to be one half of the amplitude of the frequencies being multiplied. ...Keith You win. :) When I conceived the problem I was thinking cosines actually. In which case there are no phase shifts to worry about in the result. I also forgot the half amplitude factor. While it might not be obvious, the two cases I described are basically identical. And this situation occurs in real life, i.e. in radio signals, oceanography, and guitar tuning. It follows from what is taught in high school geometry. cos(a) * cos(b) = 0.5 * (cos[a+b] + cos[a-b]) Basically: multiplying two sine waves is the same as adding the (half amplitude) sum and difference frequencies. (For sines it is sin(a) * sin(b) = 0.5 * (cos[a-b]-cos[a+b]) = 0.5 * (sin[a-b+90degrees] - sin[a+b+90degrees]) = 0.5 * (sin[a-b+90degrees] + sin[a+b-90degrees]) ) -- rb |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
On 7/4/07 7:52 AM, in article , "Ron
Baker, Pluralitas!" wrote: "Keith Dysart" wrote in message ps.com... On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. And the amplitudes of the the sum and difference frequencies need to be one half of the amplitude of the frequencies being multiplied. ...Keith You win. :) When I conceived the problem I was thinking cosines actually. In which case there are no phase shifts to worry about in the result. I also forgot the half amplitude factor. While it might not be obvious, the two cases I described are basically identical. And this situation occurs in real life, i.e. in radio signals, oceanography, and guitar tuning. It follows from what is taught in high school geometry. cos(a) * cos(b) = 0.5 * (cos[a+b] + cos[a-b]) Basically: multiplying two sine waves is the same as adding the (half amplitude) sum and difference frequencies. No, they aren't the same at all, they only appear to be the same before they are examined. The two sidebands will not have the correct phase relationship. One could, temporarily, mistake the added combination for a full carrier with independent sidebands, however. (For sines it is sin(a) * sin(b) = 0.5 * (cos[a-b]-cos[a+b]) = 0.5 * (sin[a-b+90degrees] - sin[a+b+90degrees]) = 0.5 * (sin[a-b+90degrees] + sin[a+b-90degrees]) ) -- rb |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In article ,
Ian Jackson wrote: In message , Brenda Ann writes "isw" wrote in message ... After you get done talking about modulation and sidebands, somebody might want to take a stab at explaining why, if you tune a receiver to the second harmonic (or any other harmonic) of a modulated carrier (AM or FM; makes no difference), the audio comes out sounding exactly as it does if you tune to the fundamental? That is, while the second harmonic of the carrier is twice the frequency of the fundamental, the sidebands of the second harmonic are *not* located at twice the frequencies of the sidebands of the fundamental, but rather precisely as far from the second harmonic of the carrier as they are from the fundamental. Isaac I can't speak to second harmonics of a received signal, though I can't think why they would be any different than an internal signal.. but: When you frequency multiply and FM signal in a transmitter (As used to be done on most FM transmitters in the days before PLL came along), you not only multiplied the extant frequency, but the modulation swing as well. i.e. if you start with a 1 MHz FM modualated crystal oscillator, and manage to get 500 Hz swing from the crystal (using this only as a simple example), then if you double that signal's carrier frequency, you also double the FM swing to 1 KHz. Tripling it from there would give you a 6 MHz carrier with a 3 KHz swing, and so on. For multiplying FM, yes, of course, this is exactly what happens. And as it happens for FM, it must also happen for AM. If you start with, say, a 1 MHz carrier AM modulated at 1 KHz, tuning to the second harmonic gives you a 2 MHz carrier AM modulated at 1 KHz; not 2 KHz as your "must also happen for AM" would suggest. Isaac |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In article ,
"Ron Baker, Pluralitas!" wrote: "Keith Dysart" wrote in message ps.com... On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. And the amplitudes of the the sum and difference frequencies need to be one half of the amplitude of the frequencies being multiplied. ...Keith You win. :) When I conceived the problem I was thinking cosines actually. In which case there are no phase shifts to worry about in the result. I also forgot the half amplitude factor. While it might not be obvious, the two cases I described are basically identical. And this situation occurs in real life, i.e. in radio signals, oceanography, and guitar tuning. The beat you hear during guitar tuning is not modulation; there is no non-linear process involved (i.e. no multiplication). Isaac |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
In article ,
Ian Jackson wrote: (b) In the second scenario, the 2nd harmonic is effectively present BEFORE modulation, so it gets modulated along with the fundamental. In this case, the lower frequencies of sidebands of the 2nd harmonic will be 'normal', and the signal will sound normal. I believe that will be the likely scenario for any AM transmitter which uses plate modulation or a similar "high level modulation" system. If the RF finals are running in a single-ended configuration (rather than push-pull) even the unmodulated carrier is likely to have a significant amount of second-harmonic distortion in it... and I'd think that this would tend to grow worse as the audio peaks push the finals up towards their maximum output power. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"isw" wrote in message ... snip After you get done talking about modulation and sidebands, somebody might want to take a stab at explaining why, if you tune a receiver to the second harmonic (or any other harmonic) of a modulated carrier (AM or FM; makes no difference), the audio comes out sounding exactly as it does if you tune to the fundamental? That is, while the second harmonic of the carrier is twice the frequency of the fundamental, the sidebands of the second harmonic are *not* located at twice the frequencies of the sidebands of the fundamental, but rather precisely as far from the second harmonic of the carrier as they are from the fundamental. Isaac Whoa. I thought you were smoking something but my curiosity is piqued. I tried shortwave stations and heard no harmonics. But that could be blamed on propagation. There is an AM station here at 1.21 MHz that is s9+20dB. Tuned to 2.42 MHz. Nothing. Generally the lowest harmonics should be strongest. Then I remembered that many types of non-linearity favor odd harmonics. Tuned to 3.63 MHz. Holy harmonics, batman. There it was and the modulation was not multiplied! Voices sounded normal pitch. When music was played the pitch was the same on the original and the harmonic. One clue is that the effect comes and goes rather abruptly. It seems to switch in and out rather than fade in an out. Maybe the coming and going is from switching the audio material source? This is strange. If a signal is multiplied then the sidebands should be multiplied too. Maybe the carrier generator is generating a harmonic and the harmonic is also being modulated with the normal audio in the modulator. But then that signal would have to make it through the power amp and the antenna. Possible, but why would it come and go? Strange. -- rb |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
"Don Bowey" wrote in message ... On 7/4/07 7:52 AM, in article , "Ron Baker, Pluralitas!" wrote: snip cos(a) * cos(b) = 0.5 * (cos[a+b] + cos[a-b]) Basically: multiplying two sine waves is the same as adding the (half amplitude) sum and difference frequencies. No, they aren't the same at all, they only appear to be the same before they are examined. The two sidebands will not have the correct phase relationship. What do you mean? What is the "correct" relationship? One could, temporarily, mistake the added combination for a full carrier with independent sidebands, however. (For sines it is sin(a) * sin(b) = 0.5 * (cos[a-b]-cos[a+b]) = 0.5 * (sin[a-b+90degrees] - sin[a+b+90degrees]) = 0.5 * (sin[a-b+90degrees] + sin[a+b-90degrees]) ) -- rb |
AM electromagnetic waves: 20 KHz modulation frequency on anast...
All of that crap might or might not count anyway.Us humans are NOT going
to exist for a finite number of years anyway.There is NO such thingy as time,,, your fancy numbers are meanlingeless.They do NOT amount to a hill of beans.You are an Idiot! cuhulin |
AM electromagnetic waves: 20 KHz modulation frequency onanastr...
All of that good s..t is out of the water.There is NO such thingy
asshole ass as time.y'all eggheads lost it ever since y'all was born! Metinks me needs to slap a couple of new Ray O Vac alkaline new batteries in me cute little Philips Magnvox wireless WebTV keyboard thangy now.y'all don't know ****! about batteries! cuhulin |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"isw" wrote in message ... In article , "Ron Baker, Pluralitas!" wrote: "Keith Dysart" wrote in message ps.com... On Jul 3, 2:07 pm, Keith Dysart wrote: On Jul 3, 12:50 pm, John Fields wrote: On Mon, 2 Jul 2007 23:03:36 -0700, "Ron Baker, Pluralitas!" wrote: "John Smith I" wrote in message ... Radium wrote: snip Suppose you have a 1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave. What would it look like on an oscilloscope? snip What would it look like on a spectrum analyzer? | | | | | | --------+--------------------+-------+------+---- 100kHz 0.9MHz 1MHz 1.1MHz Then suppose you have a 1.1 MHz sine wave added to a 0.9 MHz sine wave. What would that look like on an oscilloscope? snip Tricky!!! It looks like AM but it isn't, it's just the phases sliding past each other slowly and algebraically adding which creates the illusion. What would that look like on a spectrum analyzer? | | | | -----------------------------+--------------+---- 0.9MHz 1.1MHz -- JF But if you remove the half volt bias you put on the 100 kHz signal in the multiplier version, the results look exactly like the summed version, so I suggest that results are the same when a 4 quadrant multiplier is used. And since the original request was for a "1 MHz sine wave whose amplitude is multiplied by a 0.1 MHz sine wave" I think a 4 quadrant multiplier is in order. ...Keith- Ooops. I misspoke. They are not quite the same. The spectrum is the same, but if you want to get exactly the same result, the lower frequency needs a 90 degree offset and the upper frequency needs a -90 degree offset. And the amplitudes of the the sum and difference frequencies need to be one half of the amplitude of the frequencies being multiplied. ...Keith You win. :) When I conceived the problem I was thinking cosines actually. In which case there are no phase shifts to worry about in the result. I also forgot the half amplitude factor. While it might not be obvious, the two cases I described are basically identical. And this situation occurs in real life, i.e. in radio signals, oceanography, and guitar tuning. The beat you hear during guitar tuning is not modulation; there is no non-linear process involved (i.e. no multiplication). Isaac In short, the human auditory system is not linear. It has a finite resolution bandwidth. It can't resolve two tones separted by a few Hertz as two separate tones. (But if they are separted by 100 Hz they can easily be separated without hearing a beat.) The same affect can be seen on a spectrum analyzer. Give it two frequencies separated by 1 Hz. Set the resolution bandwidth to 10 Hz. You'll see the peak rise and fall at 1 Hz. |
AM electromagnetic waves: 20 KHz modulation frequency onanastr...
Dahhhhhhh,,,, BOOL SHEET! Full of Crap.
cuhulin |
AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
On Wed, 04 Jul 2007 09:11:58 -0700, isw wrote:
In article , "Ron Baker, Pluralitas!" wrote: You win. :) When I conceived the problem I was thinking cosines actually. In which case there are no phase shifts to worry about in the result. I also forgot the half amplitude factor. While it might not be obvious, the two cases I described are basically identical. And this situation occurs in real life, i.e. in radio signals, oceanography, and guitar tuning. The beat you hear during guitar tuning is not modulation; there is no non-linear process involved (i.e. no multiplication). --- That's not true. The human ear has a logarithmic amplitude response and the beat note (the difference frequency) is generated there. The sum frequency is too, but when unison is achieved it'll be at precisely twice the frequency of either fundamental and won't be noticed. -- JF |
AM electromagnetic waves: 20 KHz modulation frequency onanastronomically-low carrier frequency
On 7/4/07 10:16 AM, in article ,
"Ron Baker, Pluralitas!" wrote: "Don Bowey" wrote in message ... On 7/4/07 7:52 AM, in article , "Ron Baker, Pluralitas!" wrote: snip cos(a) * cos(b) = 0.5 * (cos[a+b] + cos[a-b]) Basically: multiplying two sine waves is the same as adding the (half amplitude) sum and difference frequencies. No, they aren't the same at all, they only appear to be the same before they are examined. The two sidebands will not have the correct phase relationship. What do you mean? What is the "correct" relationship? One could, temporarily, mistake the added combination for a full carrier with independent sidebands, however. (For sines it is sin(a) * sin(b) = 0.5 * (cos[a-b]-cos[a+b]) = 0.5 * (sin[a-b+90degrees] - sin[a+b+90degrees]) = 0.5 * (sin[a-b+90degrees] + sin[a+b-90degrees]) ) -- rb When AM is correctly accomplished (a single voiceband signal is modulated onto a carrier via a non-linear process), at an envelope detector the two sidebands will be additive. But if you independe ntly place a carrier at frequency ( c ), another carrier at ( c-1 khz) and another carrier at (c+ 1 kHz), the composite can look like an AM signal, but it is not, and only by the most extreme luck will the sidebands be additive at the detector. They would probably cycle between additive and subtractive since they have no real relationship and were not the result of amplitude modulation. |
AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency
When AM is correctly accomplished (a single voiceband signal is modulated onto a carrier via a non-linear process), at an envelope detector the two sidebands will be additive. But if you independe ntly place a carrier at frequency ( c ), another carrier at ( c-1 khz) and another carrier at (c+ 1 kHz), the composite can look like an AM signal, but it is not, and only by the most extreme luck will the sidebands be additive at the detector. They would probably cycle between additive and subtractive since they have no real relationship and were not the result of amplitude modulation. A peak detector is best understood in the time domain, try to create a simple description in the frequency domain and you can only cause confusion and incorrect conclusions. |
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