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Is AM Radio Harmful?
This is a link to an article investigating leukemia rates in areas near AM
transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. |
"lsmyer" wrote in message ... This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. Frank Dresser |
"lsmyer" wrote in message ... This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. The thoroughly undocumented cases (no studies of groundwater contamination, etc.) was based on the effects of stations with twice the power allowed in the US on AMs. Low levels of AM as experienced in the US would be very different. |
"David Eduardo" wrote in message ... The thoroughly undocumented cases (no studies of groundwater contamination, etc.) was based on the effects of stations with twice the power allowed in the US on AMs. Low levels of AM as experienced in the US would be very different. While I think this whole thing is just another pseudo-science scare.... It is NOT true that US stations have much lower field strength on AM. AFAIK, very few foreign stations are directional at any power. Some US 50 kW stations have pretty potent ERP in their beam. Not a megawatt, but quite a bit nevertheless. I'm a lot more worried about teens and others I see wandering around with a cell-phone permanently attached less than an inch from their brain. |
It's not the radiation. It's the hatred.
On 18 Aug 2004 14:15:19 GMT, "lsmyer" wrote: This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. |
"Frank Dresser" wrote in message ... Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. Hi Frank, Good point but compare to asbestos causing cancer where it can take 60 years to appear. I also often wonder what PCs are doing to us all staring at them all day, we may be in for a big health shock in the years to come! Also mobiles may ruin the brain. The consequences could be disastrous. Happy thoughts!! Cheers Mike |
On 18 Aug 2004 21:25:13 GMT, "Frank Dresser"
wrote: "lsmyer" wrote in message ... This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. Frank Dresser It is another one of these cases where there may indeed be a link, but there is no assurance at all that the link is causative. For example you can find a link between smoking and cirrosis of the liver. Many smokers are also significant drinkers. It wasn't the smoking that caused the problem, but the smoking and other behaviours that are causative are often seen together. I.E. most high power AM transmitters are in major cities, and there are significant other hazards from things like air pollution that exist independent of the AM broadcast facilities. As far as those working around the equipment, I'd be more interested in the potential X-ray exposure. The voltages used in high power transmitter tubes produce significant X-ray hazards, and these weren't recognized for a long time. |
Frank Dresser wrote:
Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. I'd sure think so. On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. At an AM station, the entire tower radiates. -- Doug Smith W9WI Pleasant View (Nashville), TN EM66 http://www.w9wi.com |
In article , lsmyer wrote:
I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. These were folks who engaged in common engineering practices like soaking a rag in carbon tetrachloride to clean PCB oil from failed capacitors out of transmitter chassis, right? God knows we all did that sort of thing... --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
The RF energy could conceivably have an effect on cell membranes and the
potentials that develop across cell membranes. Perhaps some cells are more sensitive to such changes in membrane potentials and lead to higher incidences of certain diseases which in this case is leukemia. As for not noticing the correlation for over 80 years that isn't so unusual. It really is contingent on many factors including the increase in the number of stations over the years, the increase in power over the years, the proximity of the population to RF over the years (ie. the shift from a rural to an urban population), the extent of the exposure, lifestyle and dietary changes and so on and so on. It such a case it may take quite awhile to isolate a potential causative agent and even then it wouldn't be overwhelmingly conclusive proof. Too many variables to take into account. Regards John Barnard Frank Dresser wrote: "lsmyer" wrote in message ... This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. Frank Dresser |
Is AM radio harmful ?? Only if you believe half the crap they promulgate on the talk/opinion shows. rj |
"Doug Smith W9WI" wrote
On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. At an AM station, the entire tower radiates. ___________ Also - most FM broadcast transmit antennas are arrays of several elements in a vertical stack to concentrate radiation in the horizontal plane. As a result the radiation directed around the tower base is much lower than the station's licensed power. RF Visit http://rfry.org for FM broadcast RF system papers. |
"Doug Smith W9WI" wrote in message ... Frank Dresser wrote: Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. I'd sure think so. On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. At an AM station, the entire tower radiates. One of the issues with most FM arrays with gain is that, for many, the spacing which results in the array having gain also results in a fairly pronounced hot-spot directly above the antenna, where few people would be expected to be, as well as directly below, where technical personnel might spend a substantial amount of time. Personally, I think that the AM radiation hazards are overstated in this study, and that the issue comes more from environmental circumstances by virtue of the fact that many AM transmitter installations share the same area as other industrial concerns. -- ----------------------------------------------------------------------------- If there's nothing that offends you in your community, then you know you're not living in a free society. Kim Campbell - ex-Canadian Prime Minister - 2004 ----------------------------------------------------------------------------- For direct replies, take out the contents between the hyphens. -Really!- |
"Doug Smith W9WI" wrote
On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. At an AM station, the entire tower radiates. ___________ Also - most FM broadcast transmit antennas are arrays of several elements in a vertical stack to concentrate radiation in the horizontal plane. As a result the radiation directed around the tower base is much lower than the station's licensed power. RF Visit http://rfry.org for FM broadcast RF system papers. |
"Mike Terry" wrote in message ... "Frank Dresser" wrote in message ... Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. Hi Frank, Good point but compare to asbestos causing cancer where it can take 60 years to appear. Yes, but researchers can also sift through 80 years of public health records. The people who have, or had, leukemia are known. It shouldn't be hard to find out who lived near a radio transmitter and for how long. It might be interesting to ask veterinarians about animal leukemia, since many transmitters are located in rural areas. But, since this story is being treated as news, I don't think there are even any "rural legends" about a connection between leukemia and AM radio transmitters. Let's not forget that perfectly random chance is going to usually give us lumpy results. A perfectly smooth map of leukemia cases would be something like flipping a quarter ten times and getting exactly a h-t-h-t-h-t-h-t-h-t result. It could happen, but any lumpy combination is just as likely, and there are more lumpy combinations to go around. Random chance alone might give us some leukemia hot spots. Some of those hot spots might be near AM transmitters. It'll be interesting to see if other leukemia hot spots are around AM radio transmitters, or if is just one of those weird number things. I also often wonder what PCs are doing to us all staring at them all day, we may be in for a big health shock in the years to come! Brother Stair used to say that the Internet was Satan's entryway into the home. He seems to have softened his opposition lately. His website has a page accepting donations using credit cards and paypal. Also mobiles may ruin the brain. The consequences could be disastrous. Mobiles as cellphones? Yes, there's no need to do studies to observe the brain damage caused by those evil things. Just observe the cellphone addled drivers as they careen from one close call to the next. The damage is self-evident. Well, I don't need no stinkin' cellphone to damage my brain. I'll stick with shortwave radio. Happy thoughts!! Cheers Mike Frank Dresser |
"R J Carpenter" wrote in message ... "David Eduardo" wrote in message ... The thoroughly undocumented cases (no studies of groundwater contamination, etc.) was based on the effects of stations with twice the power allowed in the US on AMs. Low levels of AM as experienced in the US would be very different. While I think this whole thing is just another pseudo-science scare.... It is NOT true that US stations have much lower field strength on AM. AFAIK, very few foreign stations are directional at any power. Some US 50 kW stations have pretty potent ERP in their beam. Not a megawatt, but quite a bit nevertheless. the field strength of AM radio stations is measured in volts (microvolts) not watts. the field strength is inversely proportional to the square of the distance. any study that relates any form of radiation, electromagnetic or otherwise that does not refer to quantities measurements AND duration of exposure to some other effect such as Leukemia is worthless. I'm a lot more worried about teens and others I see wandering around with a cell-phone permanently attached less than an inch from their brain. |
"Bob Haberkost" wrote
One of the issues with most FM arrays with gain is that, for many, the spacing which results in the array having gain also results in a fairly pronounced hot-spot directly above the antenna, where few people would be expected to be, as well as directly below... _________________ This is true only when each element in the array has high relative field at +/-90 degree elevation, and the elements are vertically spaced about one wavelength apart. Shorter vertical spacings reduce such radiation from these arrays. Using 1/2 wave spacing reduces it to a theoretical zero at +/-90 degrees elevation (the zenith and nadir). BUT, the great majority of FM broadcast transmit elements used today have elevation patterns with very low relative field at +/90 degrees. An array of such elements also has low relative field at +/-90 degrees -- even with elements spaced at one wavelength intervals. IOW, no hot-spots above and below the array. Patterns of four element types in common use today, and an elevation pattern for a 6-element, 1-wave-spaced array of one type are included in the PDF slide show listed as Paper 10 at http://rfry.org. RF |
"R J Carpenter" wrote in message ... I'm a lot more worried about teens and others I see wandering around with a cell-phone permanently attached less than an inch from their brain. And their retinas as well..... 900 mhz --- I can recall around 20 years ago (don't get on my case as to whether it was 16 or 22 or 18 years ago) but the FCC advised the amateur radio community that if you don't do something to increase your numbers, we're gonna have to start taking your VHF, UHF, microwave allocations away. This spectrum is too valuable for you to hold when your numbers are declining and you're not using them anyway. They (FCC) discussed a codeless "communicator" license. The ARRL countered with a "Novice Enhancement" program, which satisfied the Morse Code fetish requirement, and, as it turned out, did not bring the 50,000 new hams per year into the service as they claimed it would. But anyway, IIRC, somebody's idea was to allow novices voice privileges on 902 Mhz, and it was not considered seriously , and one of the reasons cited was safety. |
"Richard Fry" wrote in message ... ___________ Also - most FM broadcast transmit antennas are arrays of several elements in a vertical stack to concentrate radiation in the horizontal plane. As a result the radiation directed around the tower base is much lower than the station's licensed power. RF Right, but often times there are a large number of people living in high rise buildings near the FM antenna. It's conceivable there are more people living in a high power FM radiation area than a high power AM radiation area. Frank Dresser |
"Frank Dresser" wrote
... often times there are a large number of people living in high rise buildings near the FM antenna. It's conceivable there are more people living in a high power FM radiation area than a high power AM radiation. ________________ Could happen in the odd case, but not usually. FM broadcast transmit antennas located on building tops normally have radiation center heights that easily clear the tops of nearby buildings. If they didn't, the station's signal would be affected by shadowing (blockage) beyond the nearby buildings, and have widespread multipath problems from reflections off the building sides. Competitive issues make this situation unlikely. RF |
"Frank Dresser" wrote
... often times there are a large number of people living in high rise buildings near the FM antenna. It's conceivable there are more people living in a high power FM radiation area than a high power AM radiation. ________________ Could happen in the odd case, but not usually. FM broadcast transmit antennas located on building tops normally have radiation center heights that easily clear the tops of nearby buildings. If they didn't, the station's signal would be affected by shadowing (blockage) beyond the nearby buildings, and have widespread multipath problems from reflections off the building sides. Competitive issues make this situation unlikely. RF |
The answer to your questions are right here in the FCC's OET56
http://www.fcc.gov/Bureaus/Engineeri...56/oet56e4.pdf "lsmyer" wrote in message ... This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. |
lsmyer wrote:
This is a link to an article investigating leukemia rates in areas near AM transmitters. http://www.wired.com/news/medtech/0,1286,64579,00.html I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Maybe they got cancer from some other cause (both smoked), but I still feel like I'm inside a microwave oven anytime I'm around an AM transmitter site. AM Radio is harmful only if you listen to it. |
Buzzygirl wrote:
"Greg and Joan" wrote: But anyway, IIRC, somebody's idea was to allow novices voice privileges on 902 Mhz, and it was not considered seriously , and one of the reasons cited was safety. There is still no commercially-available equipment for the 902 MHz amateur band that I am aware of. Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
It is another one of these cases where there may indeed be a link, but
there is no assurance at all that the link is causative. For example you can find a link between smoking and cirrosis of the liver. Many smokers are also significant drinkers. It wasn't the smoking that caused the problem, but the smoking and other behaviours that are causative are often seen together. I.E. most high power AM transmitters are in major cities, and there are significant other hazards from things like air pollution that exist independent of the AM broadcast facilities. Therefore, smoke as many cigarettes as you want to, and if you get lung cancer, just blame it on the air pollution. Perhaps when I walk into a fire, the blistering burns all over my skin are caused from the chemicals in the sun tan lotion I used the day before. Voting for Nader or Badnarik is somehow taking a vote away from Kerry, but no one ever suggests Bush and Kerry drop out of the race because they are taking votes away from the other two. Ridiculous. |
Yes, but researchers can also sift through 80 years of public health
records. The people who have, or had, leukemia are known. It shouldn't be hard to find out who lived near a radio transmitter and for how long. It might be interesting to ask veterinarians about animal leukemia, since many transmitters are located in rural areas. Do you really need to have people smoke cigarettes for 80 years before you agree that inhaling smoke into your lungs is going to cause health problems? These are all basic things we should know without having to go through decades of health records to figure out. I knew in 1983 that Aspartame was a horror, yet only now are people starting to figure that out. Let's not forget that perfectly random chance is going to usually give us lumpy results. A perfectly smooth map of leukemia cases would be something like flipping a quarter ten times and getting exactly a h-t-h-t-h-t-h-t-h-t result. It could happen, but any lumpy combination is just as likely, and there are more lumpy combinations to go around. Same with trying to link lung problems with smoking. But can you seriously say that breathing smoke into your lungs is not going to cause health problems? Just use common sense. Random chance alone might give us some leukemia hot spots. Some of those hot spots might be near AM transmitters. It'll be interesting to see if other leukemia hot spots are around AM radio transmitters, or if is just one of those weird number things. While you do all that, I will just avoid living next to any AM or FM radio transmitters. I wish I could do the same with Microwave Cellular towers, but that is getting impossible to avoid today. I also often wonder what PCs are doing to us all staring at them all day, LCD screens are obviously much safer and healthier than the CRT screens. Do we really need studies on that too, or can we all use common sense to figure that one out as well? Brother Stair used to say that the Internet was Satan's entryway into the home. Satan is make-believe. Also mobiles may ruin the brain. The consequences could be disastrous. May?! Mobiles as cellphones? Yes, there's no need to do studies to observe the brain damage caused by those evil things. Exactly. |
I don't doubt that high levels of RF can be dangerous. The first two chief
engineers I worked with both died of cancer in their 50s. Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. Comparing wavelengths of "people" based on their height is ridiculous. Microwaves are a much shorter wavelength and cause much more damage to the human body, so the wavelength of people based on their height theory needs to be thrown out right away. I'd expect energy transfer to be more effiecnt from the FM broadcast antenna to the human body than it is in the AM broadcast band. This is like the argument that you should vote for the lesser of two evils, rather than vote for a good candidate. Why choose to live near an AM or FM broadcast antenna? I would not want to live next to either. What is more annoying is how cellular telephone antennas are getting to be impossible to avoid, and new ones are being put up every week. Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it seems strange this leukemia concern has gone unnoticed until now. 80 years is only one generation of people. Give it time. Old time radio commercials have doctors endorsing cigarettes that are healthy and good for you and your throat. Cell phones have not been in use long enough for the evidence to exist to convince those that don't have the radio background to know how dangerous they are now, without needing to see several generations of people suffer from them first. Aspartame is only now starting to get the attention that I was aware of decades ago. Now we have Sucralose (not sucrose) and Ace K, and again, we will have to wait around 20 years or longer before enough people have suffered to start to consider them a health threat. |
On the other hand, the FM signal is radiated from an antenna atop the
tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. This is the same theory in which people claim using their cell phones are safe, because the power they put out is so low. They are powerful enough to transmit to cell towers miles away! Now put that power inches from your head and how more concentrated is that power? |
"Truth" wrote in message ... 80 years is only one generation of people. Give it time. Old time radio commercials have doctors endorsing cigarettes that are healthy and good for you and your throat. Definition time: "Generation, interval of time between the birth of parents and the birth of their offspring. This is usually taken to be approximately 30 years. All children of one set of parents are members of the same generation although they may be years apart in age © 1993-2003 Microsoft Corporation. All rights reserved. |
"Scott Dorsey" wrote in message ... Buzzygirl wrote: "Greg and Joan" wrote: But anyway, IIRC, somebody's idea was to allow novices voice privileges on 902 Mhz, and it was not considered seriously , and one of the reasons cited was safety. There is still no commercially-available equipment for the 902 MHz amateur band that I am aware of. Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? --scott could be things have changed without me noticing but i dont think digital PSC type stuff is allowed for hams... maybe in experimantal bands? in the poplar comm freqs it just FM, ssb, AM, CW, a little FSK, some packet, a little SSTV, some full TV (usully in conjuction with emergancy support operations) anything encrypted or encoded was a big no-no |
There is still no commercially-available equipment for the 902 MHz amateur
band that I am aware of. Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? Think of it this way. When you have an FM broadcast antenna and transmitter, it makes quite a difference when switching within the same band from 88 Mhz to 100 Mhz. (only 12 Mhz) Now you want to take something from around 850 Mhz to 902 Mhz (52 Mhz difference) Plus the higher up you go, the more critical the circuitry. Even in the 440 band you are already dealing with microsurgery when using the miniature surface mount components. Besides, working with microwaves is never a good idea. Might as well just take up smoking cigarettes instead. I would play with mercury and use lead paint in my home no problem, but I would not ever build a transmitter and use microwave frequencies. |
Go to http://tx.mb21.co.uk/gallery/ and look at some of their AM/MW sites. Not only do many of them still use those cool T-shaped horizontal wire antennas, but in some shots you can see sheep grazing in the fields very close by. The RF foes in the USA should consult with veterinarians in the UK and see what their research comes up with GTT Truth wrote: Yes, but researchers can also sift through 80 years of public health records. The people who have, or had, leukemia are known. It shouldn't be hard to find out who lived near a radio transmitter and for how long. It might be interesting to ask veterinarians about animal leukemia, since many transmitters are located in rural areas. (snip) |
"Truth" wrote in message ... On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. This is the same theory in which people claim using their cell phones are safe, because the power they put out is so low. They are powerful enough to transmit to cell towers miles away! and that proves? ... nothing Now put that power inches from your head and how more concentrated is that power? why not look it up? you will find that a 5 watt transmitter operating on 450 MHz with a 1/4 wave antenna might produce enough heating to damage the cornea of the eye IF the tip is placed within one CM of the eye. |
"Truth" wrote in message ... On the other hand, the FM signal is radiated from an antenna atop the tower. Stand at the base of a 300' FM tower, and you're 300' from the thing that radiates. This is the same theory in which people claim using their cell phones are safe, because the power they put out is so low. They are powerful enough to transmit to cell towers miles away! Now put that power inches from your head and how more concentrated is that power? |
In rec.radio.shortwave Truth wrote:
I don't doubt that high levels of RF can be dangerous. The first two chief engineers I worked with both died of cancer in their 50s. Wouldn't FM broadcast antennas be an even greater concern? The height of most adults would make them resonant somewhere near, or in, the FM broadcast band. Comparing wavelengths of "people" based on their height is ridiculous. Microwaves are a much shorter wavelength and cause much more damage to the human body, so the wavelength of people based on their height theory needs to be thrown out right away. To oversimplify a bit: Low frequencies (like AM broadcast) pass through the body without being absorbed. Microwave frequencies bounce off the body without being absorbed. It's the frequency range between 30 and 300 MHz where maximum absorption takes place. Art H. |
"Truth" wrote in message ... There is still no commercially-available equipment for the 902 MHz amateur band that I am aware of. Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? Think of it this way. When you have an FM broadcast antenna and transmitter, it makes quite a difference when switching within the same band from 88 Mhz to 100 Mhz. (only 12 Mhz) Now you want to take something from around 850 Mhz to 902 Mhz (52 Mhz difference) yes but 88 to 100 = 12 percent of final freq 850 to 902 is only 5.765 per cent Plus the higher up you go, the more critical the circuitry. Even in the 440 band you are already dealing with microsurgery when using the miniature surface mount components. Besides, working with microwaves is never a good idea. Might as well just take up smoking cigarettes instead. I would play with mercury and use lead paint in my home no problem, but I would not ever build a transmitter and use microwave frequencies. |
"Truth" wrote in message ... There is still no commercially-available equipment for the 902 MHz amateur band that I am aware of. Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? Think of it this way. When you have an FM broadcast antenna and transmitter, it makes quite a difference when switching within the same band from 88 Mhz to 100 Mhz. (only 12 Mhz) Now you want to take something from around 850 Mhz to 902 Mhz (52 Mhz difference) Plus the higher up you go, the more critical the circuitry. Even in the 440 band you are already dealing with microsurgery when using the miniature surface mount components. pretty might the same for all hand held electronics these days Besides, working with microwaves is never a good idea. everyone has to have a hobby... 900 MHz are NOT microwaves (we call it microwave in brroadcast, but it is a slang term for high UHF) Might as well just take up smoking cigarettes instead. I would play with mercury and use lead paint in my home no problem, but I would not ever build a transmitter and use microwave frequencies. gunplexers are friendly... bi-directional line-of-sight audio |
Using commercially-available equipment is cheating anyway. What does it take to modify PCS cellular phone firmware for digital communication on 902? Is it just a matter of firmware or isn't the RF section able to tune that far out of band? At the time, cell phone equipment was not readily available. |
To oversimplify a bit: Low frequencies (like AM broadcast) pass through
the body without being absorbed. Microwave frequencies bounce off the body without being absorbed. ROTFFL!!! Why not PROVE your ridiculous theory by putting your head into a microwave oven! ........yeah. I didn't think so. |
Within these hallowed halls, Truth of added the
following to the collective conscience: To oversimplify a bit: Low frequencies (like AM broadcast) pass through the body without being absorbed. Microwave frequencies bounce off the body without being absorbed. ROTFFL!!! Why not PROVE your ridiculous theory by putting your head into a microwave oven! .......yeah. I didn't think so. I was actually wondering what this post of yours had to do with broadcasting. Even if it was off topic but informative or entertaining, it would have been better than just being a post about being rude to someone. |
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