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#151
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Keying The Transmitter
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#152
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One way to promote learning of code ...
wrote in message ups.com... First let me say that, in amateur radio use, the term "CW", when used to mean a mode of radio communication, is universally defined as "Morse Code radiotelegraphy by means of an on-off keyed carrier". The literal "continuous wave" meaning does not apply. Stefan Wolfe wrote: wrote in message ups.com... The big question is whether the signals (keyed carrier vs. keyed audio tone) look different on a spectrum analyzer. If they don't, why should FCC care? I agree that it doesn't matter to the FCC as long is the keyed audio tone is coupled to the radio with EM waves such as with light (optoisolators), RF or wires (electrical connections). However, if you couple the keyed audio carrier acoustically, speaker-to-mike using only sound waves, then that is J3E and only permissible in the voice portion of the band. No, that's just not true - *IF* the rig and tone are clean enough. Problems arise when the tone is not a pure sinusoid, or the transmitter does not have adequate carrier- or unwanted sideband-suppression. But that's not what is being discussed here. Feed a Morse-Code-keyed audio tone that is a pure sinusoid into an SSB transmitter of sufficient quality, and the result is "CW". It doesn't matter how the tone gets into the transmitter, as long as the process doesn't introduce other tones or artifacts. If I were to whistle nearly pure sine waves (I am a good whistler, perhaps you have seen paintings of my mother :-)) in Morse code into the mike input, it might look like CW and sound like CW but it would really be J3E, hence illegal in the CW sub-bands. No, that's not true, unless the whistle isn't a pure sine wave. Using acoustic coupling (J3E), it becomes a slippery slope; first computer generated tones, then human whistling, then humming and before you know it, "talking" (di dah di dah etc.. and finally, "words" :-)) Not a slippery slope at all. All that matters is what it looks like to a spectrum analyzer. If the whistle is a pure sine wave, the output will be a single carrier. But if it's not a pure sine wave, the result will be spectrally different, and illegal. From a regulations standpoint, it does not matter how the signal is generated. What does matter is that it meets the standards of spectrum purity. Now you might argue that a simple "CW" transmitter using keyed Class C stages and vacuum tubes can be much simpler, more electrically efficient, and certainly more elegant than a newfangled computer-SSB-transceiver-kluge-setup, yet deliver a signal of equal quality. That's true - but it's a different issue. I give up. You keep talking about how the signal looks when it is *received*. I keep talking about how the true A1A signal is supposed to be *transmitted* (your last paragraph is exactly that but you dismissed it). Part 97 is not concerned with how you receive, only how you transmit. I agree it is true that you can fool anyone on the receiving end as long as you can make the signal look like A1A on a spectrum analyzer. That might be difficult because the sidebands generated by breaking a CW "square" wave would be present on my A1A transmission and you would somehow have to re-create them on your SSB pure tone transmission that is keyed in your tightly filtered audio circuit. But re-check the definition of A1A and you will see that there is only one way to *transmit* it. And A1A is the only FCC definition of "CW". It is a moot point because tone generated data (as a sinusoidal "mark" in your SSB transmission) is legal everywhere that CW is legal. The same is not true of the voluntary band plans. It it is important to know the difference, even if you think the difference makes no difference so to speak. And I said that whistling CW into the mike is J3E voice, not A1A, and the only thing that separates it from being legal on the CW sub-bands is the way the data is coupled, not how it is received or transmitted. You completely missed all of my points. |
#153
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One way to promote learning of code ...
Stefan Wolfe wrote:
wrote in message ups.com... First let me say that, in amateur radio use, the term "CW", when used to mean a mode of radio communication, is universally defined as "Morse Code radiotelegraphy by means of an on-off keyed carrier". The literal "continuous wave" meaning does not apply. Stefan Wolfe wrote: wrote in message ups.com... The big question is whether the signals (keyed carrier vs. keyed audio tone) look different on a spectrum analyzer. If they don't, why should FCC care? I agree that it doesn't matter to the FCC as long is the keyed audio tone is coupled to the radio with EM waves such as with light (optoisolators), RF or wires (electrical connections). However, if you couple the keyed audio carrier acoustically, speaker-to-mike using only sound waves, then that is J3E and only permissible in the voice portion of the band. No, that's just not true - *IF* the rig and tone are clean enough. Problems arise when the tone is not a pure sinusoid, or the transmitter does not have adequate carrier- or unwanted sideband-suppression. But that's not what is being discussed here. Feed a Morse-Code-keyed audio tone that is a pure sinusoid into an SSB transmitter of sufficient quality, and the result is "CW". It doesn't matter how the tone gets into the transmitter, as long as the process doesn't introduce other tones or artifacts. If I were to whistle nearly pure sine waves (I am a good whistler, perhaps you have seen paintings of my mother :-)) in Morse code into the mike input, it might look like CW and sound like CW but it would really be J3E, hence illegal in the CW sub-bands. No, that's not true, unless the whistle isn't a pure sine wave. Using acoustic coupling (J3E), it becomes a slippery slope; first computer generated tones, then human whistling, then humming and before you know it, "talking" (di dah di dah etc.. and finally, "words" :-)) Not a slippery slope at all. All that matters is what it looks like to a spectrum analyzer. If the whistle is a pure sine wave, the output will be a single carrier. But if it's not a pure sine wave, the result will be spectrally different, and illegal. From a regulations standpoint, it does not matter how the signal is generated. What does matter is that it meets the standards of spectrum purity. Now you might argue that a simple "CW" transmitter using keyed Class C stages and vacuum tubes can be much simpler, more electrically efficient, and certainly more elegant than a newfangled computer-SSB-transceiver-kluge-setup, yet deliver a signal of equal quality. That's true - but it's a different issue. I give up. You keep talking about how the signal looks when it is *received*. No, I don't. I'm talking about what the signal produced by the transmitter looks like on a spectrum analyzer I keep talking about how the true A1A signal is supposed to be *transmitted* (your last paragraph is exactly that but you dismissed it). The basic point is this: FCC doesn't care *how* you generate a "CW" signal, as long as it meets the technical requirements. Part 97 is not concerned with how you receive, only how you transmit. Not "how" you transmit but "what" you transmit. The characteristics of the transmitted signal are what matters, not the technology used to generate it. I agree it is true that you can fool anyone on the receiving end as long as you can make the signal look like A1A on a spectrum analyzer. Not about fooling anyone. It's about meeting the technical requirements for signal quality. That might be difficult because the sidebands generated by breaking a CW "square" wave would be present on my A1A transmission and you would somehow have to re-create them on your SSB pure tone transmission that is keyed in your tightly filtered audio circuit. But re-check the definition of A1A and you will see that there is only one way to *transmit* it. Show us. Post the definition that says the way the signal is generated matters to FCC. And A1A is the only FCC definition of "CW". Show us. It is a moot point because tone generated data (as a sinusoidal "mark" in your SSB transmission) is legal everywhere that CW is legal. The same is not true of the voluntary band plans. It it is important to know the difference, even if you think the difference makes no difference so to speak. And I said that whistling CW into the mike is J3E voice, not A1A, and the only thing that separates it from being legal on the CW sub-bands is the way the data is coupled, not how it is received or transmitted. The way the data is coupled makes no difference. What matters are the characteristics of the transmitted signal. In practice, I don't think anyone could whistle into a mike so perfectly as to produce a "CW" signal that would be indistinguishable from one generated by more conventional means. But that's not the point. You completely missed all of my points. No, I simply pointed out your errors in interpretation of the rules. |
#154
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One way to promote learning of code ...
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#156
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One way to promote learning of code ...
Dave Heil wrote: wrote: wrote: As long as there is a single one out there... Sigh...that's about the ONLY thing that justifies their mean way of acting. How do you justify your behavior here, Len? How do you justify your behavior here, Dave? |
#157
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One way to promote learning of code ...
"Stefan Wolfe" ) writes:
I give up. You keep talking about how the signal looks when it is *received*. I keep talking about how the true A1A signal is supposed to be *transmitted* (your last paragraph is exactly that but you dismissed it). Part 97 is not concerned with how you receive, only how you transmit. I agree it is true that you can fool anyone on the receiving end as long as you can make the signal look like A1A on a spectrum analyzer. That might be difficult because the sidebands generated by breaking a CW "square" wave would be present on my A1A transmission and you would somehow have to re-create them on your SSB pure tone transmission that is keyed in your tightly filtered audio circuit. But re-check the definition of A1A and you will see that there is only one way to *transmit* it. And A1A is the only FCC definition of "CW". It is a moot point because tone generated data (as a sinusoidal "mark" in your SSB transmission) is legal everywhere that CW is legal. The same is not true of the voluntary band plans. It it is important to know the difference, even if you think the difference makes no difference so to speak. And I said that whistling CW into the mike is J3E voice, not A1A, and the only thing that separates it from being legal on the CW sub-bands is the way the data is coupled, not how it is received or transmitted. You completely missed all of my points. It has nothing to do with coupling. If you think the rules disallow the method of a tone into an SSB transmitter, then it would most definitely disallow whistling into the microphone. Here. I cooked up an example that might hopefully explain all this, but at this point I doubt it. Take a 2MHz oscillator, and you key that (or, key a buffer stage after that). Put it into a mixer, and the second input of the mixer is a 5MHz oscillator. Amplify it and feed it to the antenna. Now you've got a signal with a carrier (5MHz) and two sidebands (3MHz and 7MHz), not a good signal. So you make the mixer balanced so the oscillators don't appear at the output. That gets rid of the 5MHz "carrier", which leaves the two sidebands in place. But you don't want that, so you add some filtering to get rid of the unwanted sideband, let's make it the 3MHz signal. Thus you now end up with a 7MHz signal. How is this different from a 7MHz crystal oscillator being keyed and then amplified and feeding the antenna? How is this different from any number of SSB transmitters that also send CW? The rules don't allow it? But then a lot of SSB rigs break the rules, and that really fancy CW transmitter described in QST in the fall of 1971 would also break the rules. Oh wait, it's legal. But then why would a tone into an SSB transmitter be illegal according to the rules? The tone becomes the 2MHz oscillator. It's the same principle, just with a lower frequency being mixed with a radio freqeuncy. Of course you're going to get in trouble if you heterodyne two oscillators together and don't get rid of the unwanted signals. But, look at the output of the transmitter, and if it's designed properly and adjusted properly, you cannot tell the difference between that heterodyne transmitter and that simple 1 oscillator transmitter. You have one radio signal at the output of that transmitter, and you can't tell how it is generated. Same with injecting a tone into an SSB transmitter. You will get one signal at the output of that transmitter if the tone is pure enough and carrier and unwanted sideband are properly suppressed. You want to come up with some special case for this method, when the other rules would take care of any problems. If you've got more than one signal out of that transmitter, then you've got a spur, and there are rules about that. The rules aren't about how you can generate a spur-free signal, or allow spurs if you followed a certain scheme, they are about not allowing spurs. Take your simple CW transmitter. So the AC from the filament starts modulating the oscillator tube, and suddenly you have an AM signal (ie the keyed carrier and the two sidebands caused by the 60Hz ac signal). Nobody is going to say "Oh, you've done that wrong, it's illegal". They are going to say "You'd better do something about that AM signal in the CW band". Use an audio tone with harmonic content into the SSB transmitter and then that signal when translated to radio frequencies will result in multiple outputs, which is against the law. Have bad carrier suppression in the SSB transmitter, and you'll get two outputs, again something which is against the law. Have bad unwanted carrier suppression and you'll have to sidebands at the output of that transmitter, yet again something against the rules. But do it properly, and wham, you only have one signal and nobody know, or cares, how you generate it. Once again, it's no different than a crystal oscillator feeding an amplifier; nobody cares how you generate that CW signal, but they will care a lot if you've got hum on the signal or you've got a harmonic. In the end, you are waving your hands at your interpretation of the rules, but can't even dig up those rules that you think mean what you say. Yet you also can't explain the KWM-2 that used tone injection to generate CW (surely Collins wouldn't have used the method if it wasn't allowed) and I"m sure there were some other rigs of that same vintage that used the same scheme. There were certainly articles in the ham magazines about using the method to add CW to rigs that were SSB only. You can't explain all those hams who used a frequency shifted audio oscillator into an SSB transmitter to get FSK. Surely that would be wrong if the FCC didn't allow the use of a tone to generate CW with an SSB transmitter, though the principal is exactly the same. Michael VE2BVW |
#158
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One way to promote learning of code ...
wrote:
Dave Heil wrote: wrote: wrote: As long as there is a single one out there... Sigh...that's about the ONLY thing that justifies their mean way of acting. How do you justify your behavior here, Len? How do you justify your behavior here, Dave? That's an easy one, hot-ham-and-cheese. I don't go into a rant like Leonard Anderson. I don't pontificate in long, windy posts like Leonard Anderson. Unlike Leonard Anderson, I don't pretend to be a part of an endeavor in which I am not involved. Dave K8MN |
#159
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One way to promote learning of code ...
Dave Heil wrote: wrote: Dave Heil wrote: wrote: wrote: As long as there is a single one out there... Sigh...that's about the ONLY thing that justifies their mean way of acting. How do you justify your behavior here, Len? How do you justify your behavior here, Dave? That's an easy one, hot-ham-and-cheese. I don't go into a rant like Leonard Anderson. I don't pontificate in long, windy posts like Leonard Anderson. Unlike Leonard Anderson, I don't pretend to be a part of an endeavor in which I am not involved. Dave K8MN Lots about Len Anderson. I was hoping that you might say something about yourself... .... but I guess there isn't much to say. Your constant little jabs are enough. |
#160
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One way to promote learning of code ...
wrote in message ... On Sun, 14 Jan 2007 23:46:39 -0500, "Stefan Wolfe" wrote: wrote in message roups.com... First let me say that, in amateur radio use, the term "CW", when used to mean a mode of radio communication, is universally defined as "Morse Code radiotelegraphy by means of an on-off keyed carrier". The literal "continuous wave" meaning does not apply. Stefan Wolfe wrote: wrote in message ups.com... The big question is whether the signals (keyed carrier vs. keyed audio tone) look different on a spectrum analyzer. If they don't, why should FCC care? I agree that it doesn't matter to the FCC as long is the keyed audio tone is coupled to the radio with EM waves such as with light (optoisolators), RF or wires (electrical connections). However, if you couple the keyed audio carrier acoustically, speaker-to-mike using only sound waves, then that is J3E and only permissible in the voice portion of the band. No, that's just not true - *IF* the rig and tone are clean enough. Problems arise when the tone is not a pure sinusoid, or the transmitter does not have adequate carrier- or unwanted sideband-suppression. But that's not what is being discussed here. Feed a Morse-Code-keyed audio tone that is a pure sinusoid into an SSB transmitter of sufficient quality, and the result is "CW". It doesn't matter how the tone gets into the transmitter, as long as the process doesn't introduce other tones or artifacts. If I were to whistle nearly pure sine waves (I am a good whistler, perhaps you have seen paintings of my mother :-)) in Morse code into the mike input, it might look like CW and sound like CW but it would really be J3E, hence illegal in the CW sub-bands. No, that's not true, unless the whistle isn't a pure sine wave. Using acoustic coupling (J3E), it becomes a slippery slope; first computer generated tones, then human whistling, then humming and before you know it, "talking" (di dah di dah etc.. and finally, "words" :-)) Not a slippery slope at all. All that matters is what it looks like to a spectrum analyzer. If the whistle is a pure sine wave, the output will be a single carrier. But if it's not a pure sine wave, the result will be spectrally different, and illegal. From a regulations standpoint, it does not matter how the signal is generated. What does matter is that it meets the standards of spectrum purity. Now you might argue that a simple "CW" transmitter using keyed Class C stages and vacuum tubes can be much simpler, more electrically efficient, and certainly more elegant than a newfangled computer-SSB-transceiver-kluge-setup, yet deliver a signal of equal quality. That's true - but it's a different issue. I give up. indeed you see his style of deabte evade nit pick and sidestepp avoid anything You keep talking about how the signal looks when it is *received*. I keep talking about how the true A1A signal is supposed to be *transmitted* (your last paragraph is exactly that but you dismissed it). Part 97 is not concerned with how you receive, only how you transmit. even the rules must yeld to "logic" of the ProCoders I agree it is true that you can fool anyone on the receiving end as long as you can make the signal look like A1A on a spectrum analyzer. That might be difficult because the sidebands generated by breaking a CW "square" wave would be present on my A1A transmission and you would somehow have to re-create them on your SSB pure tone transmission that is keyed in your tightly filtered audio circuit. But re-check the definition of A1A and you will see that there is only one way to *transmit* it. And A1A is the only FCC definition of "CW". It is a moot point because tone generated data (as a sinusoidal "mark" in your SSB transmission) is legal everywhere that CW is legal. The same is not true of the voluntary band plans. It it is important to know the difference, even if you think the difference makes no difference so to speak. And I said that whistling CW into the mike is J3E voice, not A1A, and the only thing that separates it from being legal on the CW sub-bands is the way the data is coupled, not how it is received or transmitted. You completely missed all of my points. he is very good at missing points OTOH it is one of the more legit styles used by th e ProCode Luddites on here http://kb9rqz.blogspot.com/ Ummm....surprize, I am not/never was pro-code "test" but I think copying code in one's head once in a while is a good mental exercise. Do you ever do anything to exercise the mind? The physical analogue would be riding a bicycle. It has value and can be enjoyable for some but I agree you should not have to pass a bicycle riding test to get an automobile drivers license. However, as a driver, I guess I would be slightly embarrassed if people found out I did not know how to ride a bike ;-)) |
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