Re: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio
I think the real issue is not whether the problem can be solved cheaply but whether there's a demand for it. Streaming has largely replaced listening over the airwaves, especially for Millennials. In fact, I used to buy smart phones with FM receivers in them. No more, at least through Verizon. There is a demand but clearly it is smaller than it used to be. Peri -- Original Message -- From: "Lawrence Winiarski via EV" <ev@lists.evdl.org> To: "brucedp5" <bruce...@operamail.com>; "ev@lists.evdl.org" <ev@lists.evdl.org>; "Electric Vehicle Discussion List" <ev@lists.evdl.org> Sent: 10-Feb-16 2:05:02 AM Subject: Re: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio I'm just kind of learning this, so take the following with lot's of salt.comments and criticism welcome Seems to me the problem is that they are leaking high frequency noise in the AM spectrum and NOT in theFM. Not an expert, but academically, seems to me a good Faraday cage and more shielding might be the answer, rather than justgetting rid of AM. Bare unshielded wires are going to send out a lot of radiation at whatever frequency they operate at. Interesting about the old claim that FM is inherently better than AM. I think that might be an oversimplification. AM travels long long distances (because the wavelength is used is better to reflect off the upper atmosphere.) FM can'tdo that. So the SNR (signal to noise ratio) for FM is very very high for longer distances because the signal will be so weak. So it's not that crackly FM doesn't happen. It's just that people don't even bother trying to listen it's so bad. It is better than AM for short distances, but that's only at the same wattage.Also the bandwidth used for FM radio stations is greater than AM radio bandwidth, and this has a lot to do with SNR ratios as.It should be obvious that you can cure any SNR problems with stronger signal. but because of the fact that AM travels so well, makes that problematic as for station to stationinterference. At some level the distinction between AM and FM is also a little contrived. AM also varies the frequency as exploited in single sidebandreceivers. Any varying wave will have have a frequency spread. So at some level, AM is also a form of FM. I think Armstrong's old demonstrations with a tesla coil showing static on AM and not on FM, were probably more than a little disingenuous as tesla coils operate at AM frequencies. From wikipedia: In 1922, John Renshaw Carson of AT, inventor of Single-sideband modulation (SSB modulation), had published a paper in the Proceedings of the IRE arguing that FM did not appear to offer any particular advantage.[15] Armstrong managed to demonstrate the advantages of FM radio despite Carson's skepticism in a now-famous paper on FM in the Proceedings of the IRE in 1936,[16] which was reprinted in the August 1984 issue of Proceedings of the IEEE.[17]Today the consensus regarding FM is that narrow band FM is not so advantageous in terms of noise reduction, but wide band FM can bring great improvement in signal to noise ratio if the signal is stronger than a certain threshold. Hence Carson was not entirely wrong, and the Carson bandwidth rule for FM is still important today. Thus, both Carson and Armstrong ultimately contributed significantly to the science and technology of radio. The threshold concept was discussed by Murray G. Crosby (inventor of Crosby system for FM Stereo) who pointed out that for wide band FM to provide better signal to noise ratio, the signal should be above a certain threshold, according to his paper published in Proceedings of the IRE in 1937.[18] Thus Crosby's work supplemented Armstrong's paper in 1936. From: brucedp5 via EV <ev@lists.evdl.org> To: ev@lists.evdl.org Sent: Wednesday, February 10, 2016 12:16 AM Subject: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio 'EV owners Want Their AM Radio Back' http://motherboard.vice.com/en_uk/read/why-electric-cars-are-ditching-am-radio Why Electric Cars Are Ditching AM Radio 5 February 2016 MEGHAN NEAL [image https://lh5.googleusercontent.com/vzU_4bnWa0HQghXTUYtx933Gflhnp2xupQKxmpY2JdpgQuGhMQ8eIJiK4h3gv851Ym372AdcPfPGzr5UrJO6a521OhvpWpC2WR4riM6ROvb5a--5J-zO9e6_xUbHOGI5D-N0YTEq Screenshot via Tesla Motors Club ] Electric cars may be energy efficient Earth-saving futuremobiles, but their rise could also have a strange unintended consequence: killing off the oldest form of radio. Two popular electric cars, the BMW i3 and Tesla Model X, are ditching terrestrial AM radio because electromagnetic noise from the electric motor interferes with the broadcast reception, causing static, as the blog Music 3.0 recently pointed out. Electronics have always been a source of AM radio static, and electric motors are no exception. EVs are powered by a rechargeable batte
Re: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio
Sounds like they may not be compliant with FCC Part 15 "unintentional radiators" - is their AM interference limited to their own car? What does it do to the car next to them? And as a ham radio operator, dealing with the various forms of impulse and heterodyne and so forth noise already prevalent, I'd like to not see more RF pollution on the air. On that impulse noise - someone like BMW or Tesla should know there are numerous sophisticated notch filters - DSP based - available to make a lot of that noise seem to disappear. I agree the apparent lack of FM interference is more with the frequency used than the modulation scheme in this case. AM aircraft band (VHF) might similarly ignore the MF and LF interference caused by the electric motors. On Feb 10, 2016 3:05 AM, Lawrence Winiarski via EV <ev@lists.evdl.org> wrote: > > I'm just kind of learning this, so take the following with lot's of > salt.comments and criticism welcome > > Seems to me the problem is that they are leaking high frequency noise in > the AM spectrum and NOT in theFM. > > Not an expert, but academically, seems to me a good Faraday cage and more > shielding might be the answer, rather than justgetting rid of AM. Bare > unshielded wires are going to send out a lot of radiation at whatever > frequency they operate at. > > Interesting about the old claim that FM is inherently better than AM. I > think that might be an oversimplification. > AM travels long long distances (because the wavelength is used is better to > reflect off the upper atmosphere.) FM can'tdo that. So the SNR (signal to > noise ratio) for FM is very very high for longer distances because the signal > will be so weak. > So it's not that crackly FM doesn't happen. It's just that people don't > even bother trying to listen it's so bad. > > It is better than AM for short distances, but that's only at the same > wattage. Also the bandwidth used for FM radio stations > is greater than AM radio bandwidth, and this has a lot to do with SNR ratios > as. It should be obvious that you can cure any SNR problems with stronger > signal. but because of the fact that AM travels so well, makes that > problematic as for station to stationinterference. > > At some level the distinction between AM and FM is also a little contrived. > AM also varies the frequency as exploited in single sidebandreceivers. Any > varying wave will have have a frequency spread. So at some level, AM is > also a form of FM. > > I think Armstrong's old demonstrations with a tesla coil showing static on AM > and not on FM, were probably more than a little > disingenuous as tesla coils operate at AM frequencies. > > From wikipedia: > In 1922, John Renshaw Carson of AT, inventor of Single-sideband modulation > (SSB modulation), had published a paper in the Proceedings of the IRE arguing > that FM did not appear to offer any particular advantage.[15] Armstrong > managed to demonstrate the advantages of FM radio despite Carson's skepticism > in a now-famous paper on FM in the Proceedings of the IRE in 1936,[16] which > was reprinted in the August 1984 issue of Proceedings of the IEEE.[17]Today > the consensus regarding FM is that narrow band FM is not so advantageous in > terms of noise reduction, but wide band FM can bring great improvement in > signal to noise ratio if the signal is stronger than a certain threshold. > Hence Carson was not entirely wrong, and the Carson bandwidth rule for FM is > still important today. Thus, both Carson and Armstrong ultimately contributed > significantly to the science and technology of radio. The threshold concept > was discussed by Murray G. Crosby (inventor of Crosby system for FM Stereo) > who pointed out that for wide band FM to provide better signal to noise > ratio, the signal should be above a certain threshold, according to his paper > published in Proceedings of the IRE in 1937.[18] Thus Crosby's work > supplemented Armstrong's paper in 1936. > > From: brucedp5 via EV <ev@lists.evdl.org> > To: ev@lists.evdl.org > Sent: Wednesday, February 10, 2016 12:16 AM > Subject: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio > > > 'EV owners Want Their AM Radio Back' > > http://motherboard.vice.com/en_uk/read/why-electric-cars-are-ditching-am-radio > Why Electric Cars Are Ditching AM Radio > 5 February 2016 MEGHAN NEAL > > [image > https://lh5.googleusercontent.com/vzU_4bnWa0HQghXTUYtx933Gflhnp2xupQKxmpY2JdpgQuGhMQ8eIJiK4h3gv851Ym372AdcPfPGzr5UrJO6a521OhvpWpC2WR4riM6ROvb5a--5J-zO9e6_xUbHOGI5D-N0YTEq > Screenshot via Tesla Motors Club > ] > > Electric cars may be energy efficient Earth-saving futuremobiles, but their > rise could
Re: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio
On 10 Feb 2016 at 14:43, Peri Hartman via EV wrote: > Streaming has largely replaced listening over the airwaves, especially > for Millennials. I don't know about where you live, but around here, there are many places in cities and towns where the mobile signals are irregular enough to make IP service hit-and-miss. AM and FM reception are still more reliable. I suppose streaming could be done tolerably well, if the player had a huge buffer. You'd probably still lose it going through tunnels, unless the tunnels had mobile repeaters. Don't forget the substantial bandwidth cost (in $$$). The fact that mobile access is rolled into the purchase price of your EV so the manufacturer can keep tabs on you (EV ankle bracelet to complement your smartphone ankle bracelet) doesn't mean that you're not paying for it. All that said, I have to wonder about BMW. I don't see any excuse for skimping on shielding. The FCC will probably have something to say about that. In fact I wonder if they might be risking interference with emergency vehicle radios. Not smart. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio
I'm just kind of learning this, so take the following with lot's of salt.comments and criticism welcome Seems to me the problem is that they are leaking high frequency noise in the AM spectrum and NOT in theFM. Not an expert, but academically, seems to me a good Faraday cage and more shielding might be the answer, rather than justgetting rid of AM. Bare unshielded wires are going to send out a lot of radiation at whatever frequency they operate at. Interesting about the old claim that FM is inherently better than AM. I think that might be an oversimplification. AM travels long long distances (because the wavelength is used is better to reflect off the upper atmosphere.) FM can'tdo that. So the SNR (signal to noise ratio) for FM is very very high for longer distances because the signal will be so weak. So it's not that crackly FM doesn't happen. It's just that people don't even bother trying to listen it's so bad. It is better than AM for short distances, but that's only at the same wattage. Also the bandwidth used for FM radio stations is greater than AM radio bandwidth, and this has a lot to do with SNR ratios as. It should be obvious that you can cure any SNR problems with stronger signal. but because of the fact that AM travels so well, makes that problematic as for station to stationinterference. At some level the distinction between AM and FM is also a little contrived. AM also varies the frequency as exploited in single sidebandreceivers. Any varying wave will have have a frequency spread. So at some level, AM is also a form of FM. I think Armstrong's old demonstrations with a tesla coil showing static on AM and not on FM, were probably more than a little disingenuous as tesla coils operate at AM frequencies. From wikipedia: In 1922, John Renshaw Carson of AT, inventor of Single-sideband modulation (SSB modulation), had published a paper in the Proceedings of the IRE arguing that FM did not appear to offer any particular advantage.[15] Armstrong managed to demonstrate the advantages of FM radio despite Carson's skepticism in a now-famous paper on FM in the Proceedings of the IRE in 1936,[16] which was reprinted in the August 1984 issue of Proceedings of the IEEE.[17]Today the consensus regarding FM is that narrow band FM is not so advantageous in terms of noise reduction, but wide band FM can bring great improvement in signal to noise ratio if the signal is stronger than a certain threshold. Hence Carson was not entirely wrong, and the Carson bandwidth rule for FM is still important today. Thus, both Carson and Armstrong ultimately contributed significantly to the science and technology of radio. The threshold concept was discussed by Murray G. Crosby (inventor of Crosby system for FM Stereo) who pointed out that for wide band FM to provide better signal to noise ratio, the signal should be above a certain threshold, according to his paper published in Proceedings of the IRE in 1937.[18] Thus Crosby's work supplemented Armstrong's paper in 1936. From: brucedp5 via EV <ev@lists.evdl.org> To: ev@lists.evdl.org Sent: Wednesday, February 10, 2016 12:16 AM Subject: [EVDL] EVLN: Why Electric Cars Are Ditching AM Radio 'EV owners Want Their AM Radio Back' http://motherboard.vice.com/en_uk/read/why-electric-cars-are-ditching-am-radio Why Electric Cars Are Ditching AM Radio 5 February 2016 MEGHAN NEAL [image https://lh5.googleusercontent.com/vzU_4bnWa0HQghXTUYtx933Gflhnp2xupQKxmpY2JdpgQuGhMQ8eIJiK4h3gv851Ym372AdcPfPGzr5UrJO6a521OhvpWpC2WR4riM6ROvb5a--5J-zO9e6_xUbHOGI5D-N0YTEq Screenshot via Tesla Motors Club ] Electric cars may be energy efficient Earth-saving futuremobiles, but their rise could also have a strange unintended consequence: killing off the oldest form of radio. Two popular electric cars, the BMW i3 and Tesla Model X, are ditching terrestrial AM radio because electromagnetic noise from the electric motor interferes with the broadcast reception, causing static, as the blog Music 3.0 recently pointed out. Electronics have always been a source of AM radio static, and electric motors are no exception. EVs are powered by a rechargeable battery, electric motor, and a frequency converter that controls how much power the car's electrical motors put out by turning voltage on and off thousands of times a second, basically chopping up energy. This process causes electromagnetic interference that gets picked up by the radio. AM radio has always been more susceptible to static than its partner on the dial. "AM" stands for amplitude modulation, which means the height of the radio waves are varied over time to encode the information, versus “FM,” frequency modulation, which varies their speed. Since amplitude, not frequency, is affected by electrical noise emitted by gadgets like smartphones, TVs, computers, even vacuum cleaners and hairdryers, AM signals are prone to distorti
[EVDL] EVLN: Why Electric Cars Are Ditching AM Radio
'EV owners Want Their AM Radio Back' http://motherboard.vice.com/en_uk/read/why-electric-cars-are-ditching-am-radio Why Electric Cars Are Ditching AM Radio 5 February 2016 MEGHAN NEAL [image https://lh5.googleusercontent.com/vzU_4bnWa0HQghXTUYtx933Gflhnp2xupQKxmpY2JdpgQuGhMQ8eIJiK4h3gv851Ym372AdcPfPGzr5UrJO6a521OhvpWpC2WR4riM6ROvb5a--5J-zO9e6_xUbHOGI5D-N0YTEq Screenshot via Tesla Motors Club ] Electric cars may be energy efficient Earth-saving futuremobiles, but their rise could also have a strange unintended consequence: killing off the oldest form of radio. Two popular electric cars, the BMW i3 and Tesla Model X, are ditching terrestrial AM radio because electromagnetic noise from the electric motor interferes with the broadcast reception, causing static, as the blog Music 3.0 recently pointed out. Electronics have always been a source of AM radio static, and electric motors are no exception. EVs are powered by a rechargeable battery, electric motor, and a frequency converter that controls how much power the car's electrical motors put out by turning voltage on and off thousands of times a second, basically chopping up energy. This process causes electromagnetic interference that gets picked up by the radio. AM radio has always been more susceptible to static than its partner on the dial. "AM" stands for amplitude modulation, which means the height of the radio waves are varied over time to encode the information, versus “FM,” frequency modulation, which varies their speed. Since amplitude, not frequency, is affected by electrical noise emitted by gadgets like smartphones, TVs, computers, even vacuum cleaners and hairdryers, AM signals are prone to distortion and crackling. That crackle apparently just doesn’t fly with luxury auto brands. BMW spokesperson Rebecca Kiehne told me, "Electric motors cause interference on AM which is why BMW decided to remove this option. While it could be offered, BMW's performance standards are very high and we don't offer a product that meets less than those high standards." But while BMW disabled AM radio in the i3 because the company was worried customers would complain about the poor sound quality, some customers have instead taken to complaining about the lack of AM radio. Consumers took to forums to bemoan the omission, a few even saying they wouldn’t buy an i3 without it. One BMW owner commented, “I plan to drag out my portable AM radio and leave it in the car.” Some owners are hacking the car to get AM radio back. Meanwhile, the new Tesla Model X also dropped terrestrial AM radio from its infotainment dashboard—a change from the Model S. Instead, you can get most AM stations via internet radio if you go menu diving through TuneIn, a service that aggregates internet radio and traditional AM/FM stations and is the standard radio option in Tesla cars. “AM radio stations are accessible through our internet radio service in Model X. Because AM audio quality can be very poor, we offer internet radio to give our customers considerably better sound quality and reception coverage,” a Tesla spokesperson told me over email. Apparently, finding the stations isn’t always easy though; there’s a Tesla forum devoted to figuring out how to locate AM stations on the Model X. At this point you may be asking, who cares? Isn’t AM radio a dinosaur technology with one leg in the grave? Does anyone even listen to it? The answer is yes: about 3 million people listen to it every day, and five of the ten most popular radio stations in the US are AM radio. “This narrative that somehow AM radio is dying is silly,” Dennis Wharton, communications executive at the National Association of Broadcasters, told me. Despite the higher sound quality of the FM band and the ascent of satellite and internet radio, the medium of FDR’s fireside chats and Rush Limbaugh is still cemented in American culture. AM signals can travel further distances, making it popular for talk radio and local programs like weather and traffic reports or emergency response information. It’s also more affordable to get on, so is home to lots of niche stations like foreign language radio, college radio, or religious programs. “It’s a haven for minority radio stations as well—particularly Latino and Hispanic radio has moved a lot to AM radio in recent years,” said Wharton. Not to mention some major sports franchises still broadcast games, sometimes exclusively, on legacy AM stations that have been around forever and have fiercely loyal listeners. The National Association of Broadcasters (NAB) is asking BMW to reconsider its decision to drop AM radio, and NAB’s California branch has teamed up with engineers to devise a solutions to the static problem. A group of engineers in Germany are also working on a prototype for minimizing interference by shielding the engine’s cabling and insulating the motor, at a price point that’s affordable for automakers. Cars and radio have always been inextricably linked: about 90
