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#41
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![]() "Radium" wrote in message ups.com... Smarty, big thanks for your detailed response. One big advantage [that I could imagine] to using FM -- instead of AM -- to carry the luminance (Y) signal, is that you can run on your treadmill without seeing those lines on the screen mask your favorite shows. The magnetic signals generated by the electronics in the treadmill causes blinding interference on AM video. FM video is be immune to such disruptions. Unless your treadmill is doing something very unusual, the interference you are seeing is unlikely to be coming in via the RF "front end" of the TV (where the video demodulation is taking place), and so switching to FM from AM wouldn't help. (It's more than likely either magnetic interference upsetting the deflection fields - assuming a CRT-type TV - or the effects of noise coming in on the AC wiring.) FM for standard "analog" TV is virtually impossible due to the bandwidth requirements of typical FM itself. In the case of "digital" TV - well, for the moment, let's just say that the modulation system used is considerably different than anything we're talking about here, and leave it at that, OK? Bob M. |
#42
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![]() "Anim8rFSK" wrote in message ... In article , "Robert Peffers." wrote: "labtech_one" wrote in message ... "default" wrote in message ... SNIP In all fairness it is/was our fault. Theoretically (in a democracy) the people rule. We must really like the idea of war . . . -- in all fairness, the USA is a REPUBLIC, not a democracy. (Majority does NOT always rule) Is there anything to prevent a republic also being democratic? Yes As far as I know there are two definitions of, "Republic", 1. A state where supreme power is held by the people, or their elected representatives, or by an elected or nominated president. 2. Literally it means a society with equality between its members. Neither of which is the definition of Republic. While a democracy is - 1. (a), a system of government by the whole population, usu. through elected representatives. (b), a state so governed. (c), any organization governed on democratic principles. 2. an egalitarian and tolerant form of society. Well, you got that wrong as well. Can any USAsian really believe that they live in a Republic, (in the literal sense of the word)? Sure. We do. Can any USAsian really believe that they live in a "Democracy", (in the literal sense of the word)? Yes. Many many many people incorrectly believe that. The press insists on getting it wrong every day. In effect both the USA and the UK are now, "Oligarchies"- Except for the part where we're not. Oligarchy, 1 government by a small group of people. 2 a state governed in this way. 3 the members of such a government. Just consider how Bush and Blair took our two countries into wars that the public, by the large, did not want and you will see that neither state is either democratic nor republican. Even if your statement were true, your conclusion still wouldn't be. We elect these people as our servants to carry out our democratic wishes and they then become the masters and we the servants. It is long past time for the people of both democracies to reassert themselves and demand their appointed servants remain their servants rather than their leaders and/or masters. Will I now have to beware of black 'copters at dawn? I'm sure your level of dishonesty and delusion requires it. I'm so pleased to meet someone who considers themselves a much better authority on the English language than the Oxford Dictionary. Keep up the good work. Perhaps you could also define for us the meaning of, "Extraordinary Rendition", "Illegal Combatant", and, "Insurgent"? -- Robert Peffers, Kelty, Fife, Scotland, (UK). |
#43
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![]() "Radium" wrote in message oups.com... Why not carry the luminance-signal on FM and the audio-signal on AM? See the previous post; it's basically a matter of the enormous bandwidth requirements of FM (note that the standard "deviation" in FM *audio* broadcast - a measure of how "wide" the overall signal will be - is +/- 75 kHz from the nominal carrier frequency, for a 15 kHz audio bandwidth. The relationship between the transmitted signal bandwidth and the original signal bandwidth in FM is not a simple one, but let's just leave it at the point of noting that video signals are bandwidth hogs, and TV doesn't even use regular-old-AM as a result of that. (The luminance signal is actually sent via "vestigal sideband AM," one step removed from full suppressed-carrier SSB.) The audio is FM both to avoid the problems of interference bothering the sound (just as in FM radio), AND to minimize the effects of the video portions of the signal possibly interfering with the audio. A TV channel, though, has relatively lots of room for audio. Nonsense. The choices of AM and FM within the original analog standard definitions were made for some very, very good reasons. Digital television is a completely different beast, and is presently broadcast using two very different modulation schemes - the U.S. standard (ATSC) using 8-VSB, while the rest of the world (mostly) will be using COFDM under the DVB-T standard. Couldn't FSK [the digital equivalent of FM] be used for luminance [Y] signal of the digital video? FSK isn't exactly "the digital equivalent of FM" in the first place, and the short form answer is no. Digital video is carried in a completely difference manner, and there isn't exactly a readily-separable luminance "signal" as such in the transmitted signal, at least not as something you could identify on a scope as in analog TV - it's all just bits, and it's all packetized. Bob M. |
#44
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![]() "Rich Grise" wrote in message news ![]() None of this crap belongs in sci.electronics.basics. On Fri, 08 Jun 2007 06:57:37 -0700, Anim8rFSK wrote: In article , "Robert Peffers." wrote: "labtech_one" wrote in message ... "default" wrote in message ... SNIP In all fairness it is/was our fault. Theoretically (in a democracy) the people rule. We must really like the idea of war . . . -- in all fairness, the USA is a REPUBLIC, not a democracy. (Majority does NOT always rule) Is there anything to prevent a republic also being democratic? Yes As far as I know there are two definitions of, "Republic", 1. A state where supreme power is held by the people, or their elected representatives, or by an elected or nominated president. 2. Literally it means a society with equality between its members. Neither of which is the definition of Republic. While a democracy is - 1. (a), a system of government by the whole population, usu. through elected representatives. (b), a state so governed. (c), any organization governed on democratic principles. 2. an egalitarian and tolerant form of society. Well, you got that wrong as well. Can any USAsian really believe that they live in a Republic, (in the literal sense of the word)? Sure. We do. Can any USAsian really believe that they live in a "Democracy", (in the literal sense of the word)? Yes. Many many many people incorrectly believe that. The press insists on getting it wrong every day. In effect both the USA and the UK are now, "Oligarchies"- Except for the part where we're not. Oligarchy, 1 government by a small group of people. 2 a state governed in this way. 3 the members of such a government. Just consider how Bush and Blair took our two countries into wars that the public, by the large, did not want and you will see that neither state is either democratic nor republican. Even if your statement were true, your conclusion still wouldn't be. We elect these people as our servants to carry out our democratic wishes and they then become the masters and we the servants. It is long past time for the people of both democracies to reassert themselves and demand their appointed servants remain their servants rather than their leaders and/or masters. Will I now have to beware of black 'copters at dawn? I'm sure your level of dishonesty and delusion requires it. |
#45
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![]() "Rich Grise" wrote in message news ![]() None of this crap belongs in sci.electronics.basics. snip Then stop sross-posting it to all the groups you are cross-posting to. |
#46
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My compliments to Richard Crowley in his original reply. We are indeed
dealing with a troll here, admittedly a droll troll. Smarty "Bob Myers" wrote in message ... "Radium" wrote in message ups.com... Smarty, big thanks for your detailed response. One big advantage [that I could imagine] to using FM -- instead of AM -- to carry the luminance (Y) signal, is that you can run on your treadmill without seeing those lines on the screen mask your favorite shows. The magnetic signals generated by the electronics in the treadmill causes blinding interference on AM video. FM video is be immune to such disruptions. Unless your treadmill is doing something very unusual, the interference you are seeing is unlikely to be coming in via the RF "front end" of the TV (where the video demodulation is taking place), and so switching to FM from AM wouldn't help. (It's more than likely either magnetic interference upsetting the deflection fields - assuming a CRT-type TV - or the effects of noise coming in on the AC wiring.) FM for standard "analog" TV is virtually impossible due to the bandwidth requirements of typical FM itself. In the case of "digital" TV - well, for the moment, let's just say that the modulation system used is considerably different than anything we're talking about here, and leave it at that, OK? Bob M. |
#47
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"Bob Myers" wrote ...
Unless your treadmill is doing something very unusual, .... We're all betting on how long it takes you to relize that you've been trolled. |
#48
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Bob Myers wrote:
Unless your treadmill is doing something very unusual, the interference you are seeing is unlikely to be coming in via the RF "front end" of the TV (where the video demodulation is taking place), and so switching to FM from AM wouldn't help. (It's more than likely either magnetic interference upsetting the deflection fields - assuming a CRT-type TV - or the effects of noise coming in on the AC wiring.) FM for standard "analog" TV is virtually impossible due to the bandwidth requirements of typical FM itself. In the case of "digital" TV - well, for the moment, let's just say that the modulation system used is considerably different than anything we're talking about here, and leave it at that, OK? Catel made some FM return channel modulators and demodulators for CATV systems that fit into a standard 6 MHz channel spacing. They were pure ****. Murky video, at best, because of the reduced bandwidth. Metrovision had them in their community loop in Greene Township, Ohio and were connected to the United Video Cablevision community loop in Delhi Township, Ohio (Cincinnati, Ohio suburbs) that used standard VSB equipment. To add insult to injury, the school system insisted that their control point be in the Metrovision side, and they used an Apple II computer to generate video to feed the FM modulator. It was absolutely unreadable on any TV screen after passing through the Catel junk. I was in charge of the United Video end of that interconnect project. I built the headend and interconnect point with three RCA Heterodyne Signal Processors. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#49
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Radium,
I understand how magnetic fields from your treadmill interfere with your reception. The answer is actually quite simple. You need to run the treadmill in reverse, namely, you provide the power and the treadmill acts as a generator. The benefits are 3-fold: 1. The electric bill in your house will be substantially reduced, since you, and not the motor in the treadmill, create the needed energy. Rather than draw power from the wall, you will create a power source. 2. Your personal energy level will rise, and your ability to perform heavy work will improve. The many contaminants which are now (apparently) clouding your thinking process will lift, allowing you to no longer have concerns about SHF, sawtooth waveforms, or other distractions from your basic circulating chi. Your ying and yang will be simultaneously improved as well. 3. Finally, your TV reception will vastly improve, since this force of treadmill magnetic flux will not only be removed, but you will generate a positive ion flux field which will augment both AM and FM reception. It will take you some time to learn how to run backwards on your treadmill to achieve this generator action. Do not be disheartened......since the 3 benefits above are well worth the effort. Always bear in mind that a small squirrel running in its' little cage can do what you are attempting to do. It will help you to repeat the words over and over again: "I am a squirrel" "I am a squirrel" "I am a squirrel" All of us on this newsgroup know you will be successful. Smarty "Radium" wrote in message ups.com... On Jun 6, 10:35 pm, "Smarty" wrote: Radium, Some television is actually transmitted using FM modulation schemes, but not for commercial broadcasting. Examples of FM TV are ham/amateur ATV/SSTV, unlicensed 2.4 GHz surveillance links, and a number of point to point and studio to transmitter systems. FM signaling provides benefits in noise immunity and also permits better channel re-use, since it exploits one of the best features of FM called "the FM capture effect", wherein nearly equal strength signals which would otherwise interfere in AM systems will cause an FM receiver to "capture" only the stronger signal and ignore the weaker, even if differences of 1 dB of signal strength exists. There is no specific answer to what you would see as far as video patterns, and there is no reason whatsoever to expect to see sawtooth waveforms in particular. The demodulated signal from FM will conform to the spectral changes just as the demodulated signal from an AM detector would conform to amplitude changes, and random noise would be considered "snow" in either case. Unless a transmitted signal with a frequency ramp (sometimes called "a chirp") is present, the video would have no sawtooth. A Doppler radar, for example, could generate such a waveform, since some radars create chirped / swept signals. The video scan rate(s) would additionally need to be in the range of the chirp rate to create the appearance of a sawtooth. FM disturbances in the SHF band are likely to be man-made and not atmospheric, and thus only "viewable" if the "FM Video Receiver" you envision had a demodulator / discriminator whose bandwidth was tailored to a specific transmitted waveform, and even then only if sweep rates were suitable. Absent a man-made transmitter, the SHF environment is mostly thermal noise (both circuit and atmospheric) and only a radio telescope or other enormous aperture / antenna will see beyond the atmosphere. The choice of using AM versus FM is really way more complicated than "AM for audio" or "FM for digital video". When designing communication systems of any type, the engineer is faced with balancing many issues, and the channel, media, noise environment, interference sources, power budget, multipath, complexity, and cost are only a few of the considerations involved. A highly reliable cable modem to transmit fast digital content may indeed by phase modulated with an amplitude trellis; a secure and interference resistant link may use spread-spectrum frequency hopping AM for digital signaling; and FM winds up being used heavily in many voice communication systems mostly because the capture effect reduces co-channel interference. The closest I can suggest to what you might enjoy exploring would be a satellite dish and receiver designed for L band which will see and decode some broadcasting which is unprotected / unencrypted. It gets you into the range of SHF, has true TV signaling for public viewing, and is a hobbyist activity with others involved. Smarty, big thanks for your detailed response. One big advantage [that I could imagine] to using FM -- instead of AM -- to carry the luminance (Y) signal, is that you can run on your treadmill without seeing those lines on the screen mask your favorite shows. The magnetic signals generated by the electronics in the treadmill causes blinding interference on AM video. FM video is be immune to such disruptions. |
#50
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![]() "Richard Crowley" wrote in message ... "Bob Myers" wrote ... Unless your treadmill is doing something very unusual, .... We're all betting on how long it takes you to relize that you've been trolled. I've been here - and watching our friend Radium in action - for quite some time. Don't care, perhaps someone will learn something from the exchange. Bob M. |
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