Do  the  QLink  golf pendants and/or ClearWave Radio  EMF protective devices really work?
146474
I checked out those links.  It looks like a bunch of BS to me.  (FWIW, I have a BS in Physics with 33 graduate hours in Physics and a Masters in Science Ed.)\n\nFirst, the facts:  Electromagnetic Fields (EMF) are produced whenever electric charges are in motion, i.e. in all electrical devices.  Light rays are one form of EMF's.  We already know how to protect against those: Wear sunblock.  \n\nBut the EMF's that we're talking about here are radio frequency EMF's, which are much lower on the spectrum, and thus have much less energy.  The EMF's that have caused concern in the medical field are Extremely Low Frequency radio waves such as those produced by power lines.  When electricity is moving down the lines, oscillating back and forth 60 times a second, it sends off these low frequency radio waves.  Some epidemiological studies have associated long term exposure to these ELF radio waves with childhood leukemia.  This is still controversial, however, and the US EPA has not issued any official position about EMF exposure.\nIn any event, with power lines we're talking about constant exposure to relatively high (1 mG) EMF's.  You wouldn't get that from your home computer unless you parked yourself within 4 inches of it for 24 hours a day.  Remember, EMF's drop off in intensity as the square of the distance, e.g. doubling your distance reduces them by a factor of four, tripling the distance reduces them by a factor of nine.\n\nAnyway, the only real way to shield something from low frequency EMF's is to completely enclose it in a metal box or wire mesh.  These things are essentially versions of what physicists call a Faraday Cage.  The idea is that the metallic condutors absorb the EMF's so they don't penetrate the cage.  Radio engineers protect sensitive radio equipment this way.  Security experts do the same thing the other way around.  Radios, TV's and even computers and electric typewriters produce minute radio waves that can be picked up by very sensitive receivers, so to prevent spies from finding out what's going on in sensitive government sites, they shield them in metallic conductors.\n\nThe device your links show clearly does not surround you, so it can't be effective in shielding from EMFs.  All the talk about sympathetic oscillations is true but meaningless.  Any piece of metal does that; that's how antennas work.  An antenna is just a piece of metal; when a vibrating EMF hits the antenna, the electons start to vibrate in synch with it.  IOW, you could get the same result as these devices claim by just wearing a piece of metal on your chest.  The claims about blood flow, "healthy energy states", etc. are just nonsense.
322080
Hey, I found this amazing website that will teach you everything about Bluetooth Technology. It's called http://www.bluetomorrow.com/ because I am sure you will have more questions once your first is answered. Believe it or not Bluetooth is 1000 times safer than a Verizon or Sprint digital cell phone. Fortunately, the transmitting power is far too weak to result in perceptible effects in humans. Moreover, the radiation is not concentrated in a single beam; rather, it is randomly dispersed in all directions. The penetration depth of a device working in the 2.4Ghz frequency range is about 1.5cm - nothing more than a superficial absorption.
277573
Uh, no software will make a standard computer without a special radio reception card of some type sensitive to "radio waves".  If you are referring to the Wi-Fi specification, Blue tooth or some other specification, there 'could' be a group of API calls or a Java collection that could allow the specification to work.  Otherwise you are stuck with assembly language or C programs written to take control of a specialized piece of hardware.  All in all, this isn't a real good answer, simply because the question doesn't give enough detail of what you are using and wanting to achieve.  Re state it with more detail and maybe someone can give you a better answer.
274304
Here's a good source of info:\nhttp://ece-www.colorado.edu/~kuester/Coax/connchart.htm
490702
That's because its supposed to be secret! Something like the frequency and much more. We aren't permitted to braodcast anything above permitted frequency, as a part of general public. (Frequency emission includes, usage of home-RF devices) Please make sure to get information from the military if you are making a geniune effort, other than, putting the stake at risk!
342688
In a word, NO.  Now, in a much longer paragraph... :-)  After many years of study, there's not any conclusive evidence that exposure to WiFi (RF frequencies) has any effect whatsoever on living things and there are generally no health concerns, even if you placed your access point under your pillow.  RF exposure involves frequency, power and the duration of the exposure.  The human body most efficiently absorbs radio frequencies in the 30 to 300MHz range, and WiFi is at 2.4GHz.  So not only is the frequency much different, but WiFi products have strict power and RF emmissions requirements, such as 100 milliwatts maximum output power.  Plus, the WiFi RF energy is not "ionizing radiation" like it is UV light and Xrays, so WiFi frequencies pose no danger to human DNA the way prolonged sunlight UV rays cause skin cancers... What is actually of more concern is the RF energy from nearby FM radio stations!  (But they've been around much longer than WiFi, studied extensively, and again, nothing conclusive about any health concerns.)
768671
I am a paranormal investigator and have caught many things on tape.a cheap emf detector as long as it is used with caution can be found at wal-mart. in their hardware department. I use one called live wire. it is an ac sniffer just turn down the sensitivity way down and stay away from ac lines . and when you come across an emf field the tester will flash and beep.. cost about $10 have video of this in use investigator was standing still aking questions and telling spirit to make the tester beep faster or slower acording to the questions answer.. kind of cool.. \n\nhttp://www.kiestronics.com/nwopis
994708
There have been many proposals using beamed electromagnetic waves to transfer significant power, but none have been implemented on a large scale.  The proposals typically suggested a solar power energy transmitting satellite in orbit that sends microwave energy to energy receiving stations on earth.\n\nMost digital radiowaves (WiFi, digital TV, and others) are quite low power at the receiver.\n\nOne problem with "more energy through a coil" is that the reactance of a coil increases directly with frequency, and you may get more VOLTAGE but less CURRENT, so the amount of POWER won't have increased.  \n\nNikoli Tesla had a proposal to use high frequency power transmission by radiation rather than conduction, but it proved impractical, as the received power density decreases as the square of the distance from the transmitter (source), while conducted power loss in transmission lines varies directly with the distance.
388412
Actually I was working on a cloaking device.  I never built a prototype though because the raw materials would have costed me $1000.  Plus, there are several different types of metal detectors and each one has to be fooled in a slightly different fashion.  If you really want to know, just buy a cheap metal detector and see if you can fool it.  I think it can be done.  If you find a way to bypass those blatently unconstitutional airport checkpoints you've got my full support.
56370
they cause electromagnetic stroms
473172
You've actually got several concepts and questions merged together.\n\nWhen you ask "how does the aerial setup the waves from only the ac signal?"  I assume you're asking how any DC components of the signal get filtered out?\n\nA transverse electromagnetic wave involves both a VARYING electric field and a VARYING magnetic field, appearing at right angles to each other and to the direction of travel of the wave.\n\nAny DC component has no varying component, therefore, no wave is generated.  Although DC flowing through a wire creates electric and magnetic fields, no wave is generated because there is no variance in the fields.  \n\nThere are other electronics concepts that require the changing electromagnetic fields of AC to work.  A transformer uses AC, not DC.  A capacitor will block DC signals, but allow AC signals to pass.\n\nAlso, as you indicated, an efficient antenna has a matched impedance to the signal source in order to maximize the amount of engergy propagated by the antenna in the desired direction(s).
588321
No, it is not.\n\nAn antennae is a reacive circuit normally tuned to resonance at the transmitting frequency. In such case it will produce a damped series of oscillations when energised by a pulse. Theoretically it would not, if the energising signal was a perfect sine wave and cut off at the zero crossing point exactly. However no wave generated by a 1Ghz oscillator will be a perfect sine wave and therefore the tendency of the antenna circuit to oscillate will produce at least a blurring or extension of the waveform beyond the single cycle.\nIf the antenna was not resonant then it would produce reflective waveforms and these will oscillate until their energy is dissipated. \nConsidering the fact that it is not possible to create any antenna system (including the transmission line) without some SWR, then the answer to your question is no.
366217
Unless you are exposing this magnet to CRT (display tubes like TV's or computers) I doubt that much will happen. DO NOT take it aboard anything that relies on a compass for navigation!  IF you need a box to store it in that will allow very little magnetic waves to escape, I suggest a soft iron box, or...couple the NORTH pole of the magnet to the SOUTH pole of the magnet with soft iron...that will get rid of most stray field. Sounds like a lot of work unless you really need this magnet.
1060195
You seem to looking for very precice and specific information where the slightest misunderstanding in communication could be an expensive and time consuming mistake. As this is your first antenna built, much of the experience has been played by ear i'm sure, asking advice in places like this.\n\nAbout an hour ago, my sister asked what I'm doing and I said I'm answering questions. As a scientist, she caught on to the fact that anyone could say anything, regardless of the accuracy of the advice, and be trusted. \n\nGiven that your after accurate specifics, I'd suggest you contact a group or discussion panel that specialises in antennas for radio astronomy, and ask the people that acutally know what they are talking about.
481454
ADF's detect an electric field and a magnetic field which are perpendicular in space and their amplitudes vary sinusoidally with time. The magnetic field induces a voltage into the windings of the ADF loop antenna. By measuring the phase difference between the windings the ADF is able to determine the direction of the beacon. \n\nPutting beacons around the house and using ADF to navigate turns out to be expensive and inefficient as GPS and proximity sensors are available and work better.
214904
normally they work with antennas, electromagnetic fields propagation and communications systems. It has to do a lot with electrical signals and electrical behavior of components in the high frequency spectrum (normally above 9MHz, but radio signals of a few KHz might also be of interest)
1042285
It used to be a very common occurrence with the wind up watches made years ago.\nYou can take the watch to a jeweler and have it de-magnetized and it will run again , for someone else. Putting it back on the person who magnetized it in the first place will just put it back in the non usable situation again.\n\nIt's unfortunate but the condition is not something you can change.\nHowever take hope! Some of these people can successfully wear pendant watches hanging by a chain around the neck.