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A Quantum Antenna?
Hi,
I am thinking out loud about how the semiconductor LED evolved into the laser diode, by exploiting the synchronized population increase mechanism to generate monochromatic photon emission. Might it be possible to scale down this electron mechanism to usable radio frequencies and end up with a radio transmitting antenna that doesn't require aerials? Might this device then be termed a radio diode? A*s*i*m*o*v .... Anyone not wearing 2,000,000 sunblock is gonna have a REAL_ BAD_ DAY_7 |
Uh, the wavelenght of light aproaches or is about equiv to the diameter of
an atom... a "Radio Emitting Diode" (RED? as opposed to a LED) would be BIG to emit frequency on the 160 meter band! Regards, John |
"Scale up" is probably a more descriptive term than "scale down". Do you
know how big it would have to be? Roy Lewallen, W7EL Asimov wrote: Hi, I am thinking out loud about how the semiconductor LED evolved into the laser diode, by exploiting the synchronized population increase mechanism to generate monochromatic photon emission. Might it be possible to scale down this electron mechanism to usable radio frequencies and end up with a radio transmitting antenna that doesn't require aerials? Might this device then be termed a radio diode? A*s*i*m*o*v ... Anyone not wearing 2,000,000 sunblock is gonna have a REAL_ BAD_ DAY_7 |
Asimov wrote:
Hi, I am thinking out loud about how the semiconductor LED evolved into the laser diode, by exploiting the synchronized population increase mechanism to generate monochromatic photon emission. Might it be possible to scale down this electron mechanism to usable radio frequencies and end up with a radio transmitting antenna that doesn't require aerials? Might this device then be termed a radio diode? LEDs don't emit coherent radiation. All your jumbo "RED" would do would be to emit wideband noise. -- Peter |
They don't? Then hell--I am throwing this laser led away!!!
John |
"Peter Hayes" wrote in message
o.uk... LEDs don't emit coherent radiation. All your jumbo "RED" would do would be to emit wideband noise. It's not THAT wide, is it? Anyone know the Q of an LED? I'd guess it's at least 10... |
Actually, a "RED" in ultra-high Ghz is NOT a bad idea--I bet that is on
someones design system! It actually would not surprize me if the military wasn't already planning a weapon on such a device--and this is why we have not heard about it... of course--I may have just forgotten my medication and it is those damn delusions again! grin Regards, John |
On Thu, 28 Apr 2005 17:52:49 -0700, "John Smith"
wrote: Actually, a "RED" in ultra-high Ghz is NOT a bad idea--I bet that is on someones design system! They used to call it a MASER. If it had been such a good idea, it would still be a good idea. |
Richard:
Don't spoil the fun! sad-face Warmest regards, John |
John Smith wrote:
"Don`t spoil the fun! sad-face" According to my online encyclopedia, the Maser is not new. It appeared in the Soviet Union about 1952 and was quickly adopted in the U.S.A.. Early Masers got stimulated emission in a stream of energized ammonia molecules at 24 gigahertz. Nobel prizes in physics were awarded in 1964 for Maser developments. The last 40 years has seen emphasis shift to Optical Masers (Lasers). These now have many applications from surgery to chart pointers. They are also used to cut metal. Not quite as many varieties as Baskin & Robbins yet, but the game is new. Lasers come in many colors and power levels. Wavelengths are in hundreds of nanometers. 193 nm is UV and comes from argon flouride. 10,600 nm is FIR from Carbon Dioxide. This is the metal cutter. Find the right material and discover how to tune it to the frequency of your choice. You may have a new HF generator. You may not have obviated wave guides and antennas appropriate to the frequency. Best regards, Richard Harrison, KB5WZI |
I have a high-power LED flashlight, 5 superbright leds in the element... it
is bright, if I bring it near an AM radios I lose all reception... this rfi is solely the product of the leds, the connecting wires and the batteries--the flashlight housing is aluminum... I have never checked just how large a bandwidth the rfi covers... Regards, John |
Yes, I would think there are MASERs in operation somewhere... they are
interesting devices--I don't think we have heard the last of them, by a long shot... The information you posted is interesting, I was not aware it was a Russian discovery, or discovered in the year I was born! Thanks for that bit of history... Regards, John |
Your flashlight likely has a DC-DC converter in it to keep the light
output relatively constant as the battery voltage drops. That would be the source of the RFI. It's also possible that the LEDs are multiplexed so that one won't hog all the current as they would if parallel connected. That also could create considerable RFI. Although the RFI is radiating from the components you mention, they aren't its source. Roy Lewallen, W7EL John Smith wrote: I have a high-power LED flashlight, 5 superbright leds in the element... it is bright, if I bring it near an AM radios I lose all reception... this rfi is solely the product of the leds, the connecting wires and the batteries--the flashlight housing is aluminum... I have never checked just how large a bandwidth the rfi covers... Regards, John |
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John Smith wrote:
"I have a high power LED flashlight. 5 superbright LED`s in the element...it is bright. If I bring it near an AM radio, I lose all reception." I have a Timex Indeglow watch with a fairly dim dial illumination when I depress the dialstem. It wipes out radio reception too. I suspect that solidstate diodes are noidy devices. They are efficient though as the light is not accompanied with much heat. As for diode noise, zeners are often used as noise generators, are they not? There are various ways to get an atom`s orbital electrons to move to a higher energy level. You can throw a stick on a fire or aim an electron beam on a CRT phospher.. From a laser, we`re looking for coherent radiation. Best regards, Richard Harrison, KB5WZI |
Well, you might be right at that (and contrary to how you took my posts--I
DO recognize you as an authority which has been around the block many more times than I), however, I have had that flashlight apart a half-dozen times, at least, it cannot be found! But, it is quite possible the current limiter is right on the chip with the LEDS and potted with it in the LED lenses... all five LEDS run in parallel.... Warmest regards, John |
I remember that "death ray" one!!!! I darn near died laughing when I seen
that--back then--and darn near died laughing again--just now--your reminding me of it!!! But then, I have a quirk, I am probably the only one... I have a VERY LOW respect for lawyers... grin Warmest regards, John |
There are various ways to get an atom`s orbital electrons to move to a
higher energy level... Your sentence, above, triggered some questions I have had in the back of my mind... In older lasers, they were referred to as "pumps", and indeed the light souce always seemed to be "strobed." I wonder if a LED is not "strobed", either occuring as a natural property of the LED itself, or circuitry incorporated on the LED chip, itself, which "strobes" it? Mainly, I have considered the above in regards to wondering about giant sheets of polished aluminum, focusing the sun on a laser rod (or gas tube) and beaming the energy down to the planet (as has been proposed by others), and if someway to "strobe" the lightsouce would have to be devised? And, this in regards to the "pump"-ing action I have heard referenced... as, if I understand it correctly, you must kick (pump) the electrons up a level, then let them oscillate back to their original state, then kick-pump them again... as the actual light is generated by the electrons shifting states, and NOT just the fact that they are at another energy level... It seemed to me the answer would be easy to find, from a search of the web... I was not successful... Your thoughts/knowledge? Regards, John |
Now, that got my attention. I haven't kept up well with LED technology,
but I haven't heard of any LEDs that have a built-in regulator, switching or otherwise. Out of curiosity, I tested the LED lights I have with an AM radio, and found the following: 1. A three-LED headlamp with no obvious electronics, fixed intensity, runs from 3 AAA cells: Quiet, no RFI. 2. Two different LED headlamps, one with 3 and the other 4 LEDs, with several intensity settings, run from 3 AAA cells: Loud audio whine. 3. Two small UV LED lights, run from 3 button cells: Quiet, no RFI. 4. Newly purchased one-LED flashlight, runs from a single AA cell: Generates an RF hiss. This is about what I expected. The #2 headlamps switch the lights on and off with varying duty cycle to get the different intensities. This can be seen by rapidly moving the light while on. The switching isn't visible at the maximum brightness setting but apparently the switcher is still on. It might be doubling as a regulator. High intensity LEDs seem to require about 4.5 volts for full brightness, and one cell is nowhere near enough to light one up without a DC-DC converter. So the #4 light has to have one. That explains its RFI. Built-in converters seem to be getting more common; without one, batteries last an incredible length of time, but at the expense of light intensity that falls dramatically as the battery discharges, especially during the first part of the discharge period. So unless there's some sort of LED defect that can cause RF noise, my money's still on your having some kind of converter or switch hidden in your flashlight somewhere. All the lights I have which don't have either are quiet. Roy Lewallen, W7EL John Smith wrote: Well, you might be right at that (and contrary to how you took my posts--I DO recognize you as an authority which has been around the block many more times than I), however, I have had that flashlight apart a half-dozen times, at least, it cannot be found! But, it is quite possible the current limiter is right on the chip with the LEDS and potted with it in the LED lenses... all five LEDS run in parallel.... Warmest regards, John |
John Smith wrote:
I have a high-power LED flashlight, 5 superbright leds in the element... it is bright, if I bring it near an AM radios I lose all reception... this rfi is solely the product of the leds, the connecting wires and the batteries--the flashlight housing is aluminum... I have never checked just how large a bandwidth the rfi covers... The LEDs may be pulsed by something resembling a square wave duty cycle thus generating a host of harmonics. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
On Fri, 29 Apr 2005 02:43:31 -0700, Roy Lewallen
wrote: There is a letter on this very subject in the Pease Porridge column of the latest issue of "Electronic Design." Now, that got my attention. I haven't kept up well with LED technology, but I haven't heard of any LEDs that have a built-in regulator, switching or otherwise. Out of curiosity, I tested the LED lights I have with an AM radio, and found the following: 1. A three-LED headlamp with no obvious electronics, fixed intensity, runs from 3 AAA cells: Quiet, no RFI. 2. Two different LED headlamps, one with 3 and the other 4 LEDs, with several intensity settings, run from 3 AAA cells: Loud audio whine. 3. Two small UV LED lights, run from 3 button cells: Quiet, no RFI. 4. Newly purchased one-LED flashlight, runs from a single AA cell: Generates an RF hiss. This is about what I expected. The #2 headlamps switch the lights on and off with varying duty cycle to get the different intensities. This can be seen by rapidly moving the light while on. The switching isn't visible at the maximum brightness setting but apparently the switcher is still on. It might be doubling as a regulator. High intensity LEDs seem to require about 4.5 volts for full brightness, and one cell is nowhere near enough to light one up without a DC-DC converter. So the #4 light has to have one. That explains its RFI. Built-in converters seem to be getting more common; without one, batteries last an incredible length of time, but at the expense of light intensity that falls dramatically as the battery discharges, especially during the first part of the discharge period. So unless there's some sort of LED defect that can cause RF noise, my money's still on your having some kind of converter or switch hidden in your flashlight somewhere. All the lights I have which don't have either are quiet. Roy Lewallen, W7EL John Smith wrote: Well, you might be right at that (and contrary to how you took my posts--I DO recognize you as an authority which has been around the block many more times than I), however, I have had that flashlight apart a half-dozen times, at least, it cannot be found! But, it is quite possible the current limiter is right on the chip with the LEDS and potted with it in the LED lenses... all five LEDS run in parallel.... Warmest regards, John |
On Fri, 29 Apr 2005 02:43:31 -0700, Roy Lewallen
wrote: I haven't kept up well with LED technology, but I haven't heard of any LEDs that have a built-in regulator, switching or otherwise. Hi Roy, Constant current LEDs have been around since the late 70s. They were marginally common then, but I rarely see them now. As for the spectrum of LEDs, the all require different battery voltages to bring them to full output. Light power is always expressed as a function of current, not voltage however. The voltage is somewhat likened to the forward conduction knee. IR LEDs have the lowest knee voltage, roughly at the same potential as common diodes: 0.6V. Blue LEDs have the highest knee voltage, roughly 3V to 3.5V. The colors Red, Orange, Yellow, Green, Aquamarine, Blue, UV exhibit the order of ascending voltage (and in the conventional order of wavelength for a rainbow). The White LED is simply a Blue or UV LED coated with phosphor (a solid state fluorescent light). 73's Richard Clark, KB7QHC |
On Fri, 29 Apr 2005 00:37:12 -0700, "John Smith"
wrote: I wonder if a LED is not "strobed", either occuring as a natural property of the LED itself, or circuitry incorporated on the LED chip, itself, which "strobes" it? Hi Brett, The voltage supplied to the LED elevates the electron out of one orbital to the conduction band. When it falls back, a photon is emitted. The wavelength of the emitted photon is the path length the electron follows spiraling from one orbital to the other (DeBroglie wave). There are no lasers that are pumped in a cyclic sense except those that emit a pulse like the old CO2 UV lasers. I had a buddy who built one that used plate glass and aluminum foil to build the high voltage charge used to excite the gas to lasing (you still need an optically resonant chamber to build the intensity). This design, from the pages of Scientific American's Amateur Scientist column exhibited a very high peak power because of the extremely short pulse duration. His knowing this instilled the caution to aim it out the window into free space for its inaugural firing. When he pulsed it he cracked the window. Window glass is not perfectly transmissive, and the high peak power and short interval conspired to create a very hot dislocality - the glass couldn't shed the heat fast enough and it cracked. 73's Richard Clark, KB7QHC |
Phosphor? Wow, that fact had missed me totally...
The lifetime rating on those white LEDs are incredible!!! From seeing crt tubes degrade over time, I'd expect there to be some sort of problem with the phosphor over such a long lifetime? A crt fails/dims due to air entering the tube, possibly? regards, john |
Richard Clark wrote: The wavelength of the emitted photon is the path length the electron follows spiraling from one orbital to the other (DeBroglie wave). Actually, I think it's more of a quantum thing - a function of the band gap energy E, which is equal to hv (read h nu) where h is Planck's constant. Wavelenth is of course related to v by a constant, c (speed of light). Lambda = c/v. So wavelength = hc/E. If it was a DeBroglie thing, wavelength would depend on the momentum of the particle as h/p. The band gap energy is not determined by the energy carried by the particle, (or by the length of its path), but by the atomic nature of the material comprising the LED, and the difference in energy between the conduction band and the valence band of that material. ac6xg |
Probably... and those of us who have taken calculus and spent years of our
life closely working with mathematicians (or, those truck drivers who had an uncanny interest in math and have studied it in great detail--just for self-satisfaction) grasp the general concept--however, a wise-intelligent individual tries to express the complex in terms where the greatest numbers can make use of the knowledge, especially, when debates/arguments and proofs are offered in such a public forum as usenet--here, your explaination fails... I would venture that to most--this looks like nothing more than you stroking your ego... Regards, John |
On Fri, 29 Apr 2005 09:05:27 -0700, "John Smith"
wrote: A crt fails/dims due to air entering the tube, possibly? Hi Brett, I've seen air enter the tube - perhaps, but there are more conventional explanations. Those episodes of "seeing" it enter were slightly less than catastrophic (accidentally broke the final seal, which, as it happens, is the right way to de-activate them). Principally it is the oxidation of the cathode (one reason why tubes have scavengers) from what air had remained from the production cycle. Back when I did TV repair as a teen, and then later in the Navy as part of a Christmas charity project, we used what was called a "rejuvenator." This piece of gear would apply several hundred to a thousand volts between the cathode and the first grid (usually a cylindrical shield capped with a plate with a pinhole in it) and hold the voltage there for a couple of seconds (manufacturer's recommended time). This would produce a current that would rip the surface of the cathode open revealing a new emitting area and the tube would come to life for another 6 months. Well, during the extended project in the Navy, we found any number of tubes that refused this Lazarus treatment. We simply held the button down for 30-60 seconds as they sizzled. Who cared? It often convinced the tube that there was more to life than consignment to the dumpster (the guys loved to give them the heave-ho to thundering explosion). The only downside to this aggressive treatment was that in ripping open the surface, part of the current was a debris stream towards the grid that would occlude the pin hole. Sort of self defeating when you think about it (and good reason for the recommended couple of seconds instead of our heavy thumb). All rather remote possibilities for the White LED. LEDs suffer other problems in commercial service. Usually with aging where the half-life is quicker than expected. Another problem is with what is called sun bleaching (usually the problem of LED traffic lights). I would suspect either, or both, to be issues with vendors and poor QA or selection. There are a world of "ultra-bright" specifications that wander the map. 73's Richard Clark, KB7QHC |
On Fri, 29 Apr 2005 12:47:18 -0700, Jim Kelley
wrote: Richard Clark wrote: The wavelength of the emitted photon is the path length the electron follows spiraling from one orbital to the other (DeBroglie wave). Actually, I think it's more of a quantum thing Hi Jim, The De Broglie [my spelling error] wave is a quantum thing. In fact Louis de Brolie presented in 1924 that MATTER was composed of discrete wavelengths (quanta). His was the identical treatment of Einstein's proposition with light. Both he and Einstein had revealed the duality of nature, and De Broglie's assertions were proven in 1927. The effect of his work left Schrodinger with the starting point for his development of quantum mechanics. 73's Richard Clark, KB7QHC |
Damn...
That is all silly... But, hey, does that light bulb in the refrig really go out when I close the door? Or, is it too subject to the quantum laws, and it only depends on an observer? grin Regards, John |
On Fri, 29 Apr 2005 14:30:01 -0700, "John Smith"
wrote: But, hey, does that light bulb in the refrig really go out when I close the door? Or, is it too subject to the quantum laws Only if Schrodinger's cat was inside to watch. |
Richard is quite correct, tho to older hams, believe the
term he uses for "Scavengers", were called "GETTERS", and were to claim any free gas's in a tube (this is anchient history!). And, another method that was used , was an "Extender", which was in reality, nothing more than a step- up transformer for the filament, raiseing the voltage (and hence the cathode temperature) by 1 to 2 tenths of a volt. these were also (a variation of this principle) available on telephone microwave carriers , where the klystrons cost several hundreds of $$$ . These, normally set the voltage at 6.3 volts, but you could (at your own risk) turn it as high as 7 volts. But, normally didn't exceed 6.5 volts. and to give an idea just how prudent, the receive local oscillators is some of that equipment, (according to the date codes), lasted in excess of 20 YEARS continious service! It wasn't the phospors that deteriorated, but the free electrons that the cathode could radiate! And, as a side note, Southern Pacific, found an outfit that would replace the filiment/cathode and rebuild those same klystrons , at about 1/4 the price of the new ones- the original equipment was made by Lenkurt , about 1960 vintage and only , about 8 years ago was finally retired, replaced with solid state, mostly digital, but some analog equipment! If this hasn't boored you by now, dont know what it will take! As info, Jim NN7K (really dates me) ! Richard Clark wrote: On Fri, 29 Apr 2005 09:05:27 -0700, "John Smith" wrote: A crt fails/dims due to air entering the tube, possibly? Hi Brett, Principally it is the oxidation of the cathode (one reason why tubes have scavengers) from what air had remained from the production cycle. Snip Back when I did TV repair as a teen, and then later in the Navy as part of a Christmas charity project, we used what was called a "rejuvenator." snip This piece of gear would apply several hundred to a thousand volts between the cathode and the first grid (usually a cylindrical shield capped with a plate with a pinhole in it) and hold the voltage there for a couple of seconds (manufacturer's recommended time). This would produce a current that would rip the surface of the cathode open revealing a new emitting area and the tube would come to life for another 6 months. snip again! 73's Richard Clark, KB7QHC |
Ahhh, the cat... likely someone just forgot to put it out...
Warmest regards, John |
Indiglo uses an electroluminescent panel that's powered by an inverter.
It takes something like 100V to light it. It's probably the inverter that's causing the RFI. |
Geneb wrote:
"Indiglo uses an electroluminescent panel that`s powered by an inverter." The whine says you`re right. Best regards, Richard Harrison, KB5WZI |
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