Lol, you have no experience in biology or the effects of non-ionizing radia tion exposure to humans. You base your concern on the particular frequency of 2.4 GHz on the fact that microwave ovens operate at that frequency rath er than looking at the absorption spectrum of biological tissues (which inc lude water). So you are forming opinions on a near complete lack of knowle dge.
Clearly you are the bigger idiot here.
It's actually easy to read a little and educate yourself on the matter. Wh y not do that rather than spreading unfounded FUD?
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Rick C.
++ Get 1,000 miles of free Supercharging
The worst that can happen is it will give you cancer and kill you. But look at it from the bright side. Some lawyer will make lots of money after you die from suing the cellular company. And we all know you want to support the lawyer and his family. So tell the cellular company to aim it at your house and increase the power.
On a sunny day (Mon, 10 Jun 2019 11:09:56 +0200) it happened Jeroen Belleman wrote in :
I am absolutely against dB in this contest.
This is from the asm source code of gm_pic that I wrote in year 2010 and have been running 24/7 ever since, logging radiation,
The GM tube is an old mil one and has a background of about 10 ticks per minute. #define GM_TUBE_SENSITIVITY D'10'
; General: ; This software is supposed to be used with a FHZ76V GM tube, specification: ; detection of gamma and beta radiation ; When measuring gamma the range is 0 to 1 R/h ; voltage: 500 V ; voltage drop when ionised 330 - 380 V ; life expectancy: > 3.10^9 impulses ; temperature range: -40 to +50 C ; temperature coefficient .2 V / C ; Nulleffect 5 to 12 impulses / minute without lead screening
; This sets the GM tube sensitivity so we can calculate uSv from cmp ; For a 1 R/h GM tube 10, for .1 R/h GM tube 100, etc.
; for a FHZ76V 1R/h GM tube: #define GM_TUBE_SENSITIVITY D'10'
; Also look for 'GM TUBE DEPENDENT' in the code, and change that if using and other GM tube, to get the correct accumulated dose.
; About the units: ; If we assume the null count is 10 cmp for natural background with this tube, then that would be .01 mR/h. ; .01 mR/h corresponds to 0.1 uSv. ; Natural background radiaton depends on where you are, I have measured here between 0 and 18 cmp. ; So all we have to do is divide the cmp by 100 to get uSv ; The following values apply to the use in Rems / hour, and Sievert / hour: ; 10 cpm = 10 uR = 0.1 uSv background radiation ; 100 cpm = 100 uR = 1 uSv low level radiation ; 1000 cmp = 1 mR = 10 uSv daily human limit rate ; 10 000 cpm = 10 mR = 100 uSv get out of there ; 100 000 cpm = 100 mR = 1 mSv substantial exposure ; 1 000 000 cpm = 1 R = 10 mSv bye bye ; 10 000 000 cmp = 10 R = 100 mSv extreme danger ; 100 000 000 cmp = 100 R = 1 Sv 50% chance of death
A very simple system. So if you hear (10,000 / 60) = 166 Hz, even without looking at the LCD display, you run.
So values change a bit... Using cpm is much easier.
From the log file: cpm 15:55 7 cpm 15:56 7 cpm 15:57 6
formatting link
I have an other one with a more sensitve tube average maybe 20 cpm for background, it can log to SDcard with location for example for prospecting or to see where you got radiated and when
I forgot to include an example of the above problem.
Baseball is a balancing act, where opposing teams engage in mock combat using a stick and ball. As the stick and ball change hands throughout the game, the resulting excitement is sometimes fun to watch. However, the ultimate most successful game, performed by the pitcher from one side, is what is called a shutout: The end result of a shutout is that nothing happens. While this might be great for the reputation of the pitcher, it does nothing for the audience. The audience attends the game to witness a mock battle and should, by conventional reasoning and logic, view the resultant inactivity as terminally boring.
Perhaps you could announce that you'll buy a darker pencil and make future schematics more legible? Extra credit for using schematic capture software. I really like many of the things you are doing, and would like to build a few. I'll have more time after I retire. Decoding the schematics is currently difficult and potentially error prone. To improve the contrast, I've tried image enhancement software which doesn't help much due to uneven brightness across the image. The illegible schematics are oddly a good thing because they force me to understand what is happening and how everything works before I can deduce where the almost invisible wires and components should be connected. I guess if it were easy, it would not be fun.
You're welcome. I try to be helpful and generally diplomatic.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
I'm not suggesting that he convert his house into an RF screen room or RF anechoic chamber. Such a house or room would not be livable or comfortable. However, for blocking mmWave frequencies, the mesh would need to be very tightly woven. Unless there is a need to be porous to pass air, using soldered sheet copper would be more effective. However, that's expensive, heavy, and a thermal nightmare. Because it has no gaps, sheets of conductive material, with fairly low resistivity, would be much cheaper and easier.
In the distant past, I would hold a wet towel over large parts of the frontal area of a dish antenna, to estimate the fade margin. When I tried the same thing with aluminum foil, I had all kinds of reflections bouncing around the dish. With an RF absorber, there were no reflections to ruin my test. Hanging wet towels inside the house might work, but the high humidity, mold, and mildew problems would make it impractical.
Actually, the solution to reducing indoor RF "electro-smog" is not in shielding the walls. It's to shield the doors and windows. Modern construction uses aluminum foil backed insulation in the walls. Most of the other construction materials (especially those containing water such as concrete) are RF absorbers. Existing walls are probably sufficient to block anything at mmWave frequencies. However, the doors and windows tend to be wide open and leak RF badly. Conductive glass Low-E glass does tolerably well at blocking cellular and mmWave frequencies. For doors, and to improve RF blocking through windows, aluminum bug screening is probably adequate.
Reflections is also the reason a tin foil hat doesn't really work. Since the parabolic shape of the reflective skull cap will concentrate any RF that enters the head to a fairly small volume inside the brain. Putting a cell phone antenna in your mouth while wearing a tin foil kippah might concentrate the RF sufficiently to fry the brain cells at the focus. Wearing a carbon doped towel or hat would be much more effective. Most of these use a wire mesh or metal wires woven into the fabric, but some use conductive materials with fairly low sheet resistivity: The resistivity is high enough to act as an absorber and would probably work quite well.
Since the electrosensitive and RF paranoia market seems to be growing with the invention of 5g technology, RF shielding products are appearing on the market. They offer EMF shielding wallpaper: including some designed especially for 5g mmWave frequencies: or are adapted from available clothing:
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
That's in the 1.2GHz ham band. Are you sure about that?
The original ovens were designed to work at 915MHz. See paragraph starting with "The microwave frequencies used in..."
I'm told that big industrial MW ovens, such as fruit dryers and plastic dryers, still use 915MHz, but all that I've seen use 2.4Ghz.
The 900 MHz ISM (industrial, scientific, medical) band is not recognized in every country. So, to be able to sell the same product anywhere on the planet, the operating frequency was moved to 2.4GHz, which is recognized in all the ITU regions. The higher frequency also has the economic advantages of using a smaller magnetron, smaller waveguide, and smaller door seal choke ring. The down side of this frequency change is that 915MHz cooks more uniformly.
Why don't microwaves use 915 MHz? (3:06)
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
After WWII most microwave bands were allocated for radio location (radar). Any other microwave communications user wanted to stay as far as possible away from the radars that caused a lot of interference.
Radio amateurs were allowed to share those huge radiolocation allocations on secondary bases i.e not causing interference to the primary user (radar) and had to accept interference from primary user. For this reason ham allocations were huge.
During years radar technology improved with better stability and spectral purity. Other paying customers wanted more and more spectrum, thus the radiolocation allocations were reduced and as a consequence also ham microwave allocations were reduced. Those hams that the ham microwave allocation is reduced now and then don't seem to know the history.
As you pointed out, 915 MHz band is only available in ITU Region 2 (Americas) but not in Region 1 (Europe). For this reason the 1.2 GHz band was used by microwave ovens in 1960/70's in Europe.
I am always reading about 5G opposition groups. I have been trying to find comparative data of towers vs hand held and ear position cell phones on signal levels. These people seem OK using cell phones but fear towers.
There appears to be a lot of measurements during the last decade of 28 GHz propagation through various building materials. It appears that the attenuation through concrete walls and tinted (IR-reflective) window glasses is about 30 to 40 dB. This should reduce the indoor exposure from a nearby base stations significantly.
For lighter building materials and ordinary window glass the attenuation is much less.
Already with 2G/3G/4G systems people living in concrete houses with tinted window glass have problems communicating with the base station. If the communication somehow is possible, the handset will have to use full power to reach the base station, not a desirable situation.
Passive repeaters (indoor and outdoor antennas with coaxial cable through the wall) are tried, but you have to keep the handset very close to the indoor antenna.
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