Talk:Extremely low frequency

message: The frequency range quoted (3-30 Hz) seems to be in error. According to the IARC Monograph on Static and Extremely Low-Frequency (ELF) Electric and Magnetic Fields, the "extremely low-frequency (ELF) range [is from] (3–3000 Hz)." ralian 03:28, 24 October 2007 (UTC)
thread_title:  Frequency range 

message: Can ELF waves/arrays cause harm to living creatures? - Zepheus 19:57, 31 May 2006 (UTC)
thread_title:  harm to humans. 

message: Can ELF waves effect brainwaves? 
http://www.borderlands.com/archives/arch/elf.htm
::From reading the information the author of that article gave, which is the same experiment in the link above, incidentally, there is a big problem with the experimental setup.
The author, Walonick, sated the following: 
"The transducer was a 24" diameter hand-wound coil,  consisting of 1000' of #25 magnetic wire. The coil had a DC  resistance of 32.4 ohms. It was mounted on a 26" square  piece of bakalite board for stability."
This describes the antenna.  Further down the article:
"The voltage fed to the coil was 3.1 VAC (RMS). The coil  was positioned 18" in front of the subjects head. The  outputs from the ELF transmitter (function generator) and the  brain wave monitor were fed directly into the computer A to D  board, allowing both to be displayed on the computer monitor (and  recorded on disk) simultaneously."
There are several fundamental issues with this experiment, the first being that unless it was a Placebo/double blind trial, it was non-functional.
The coil described would have an inductance of about 5mH, which would have a resonant frequency of 2kHz.  As this is being used as an antenna, I've computed a -69dB Gain.  The input is 3.1VAC RMS, with a source impedance of 600 Ohms for the signal generator given.  The impedance mismatch of 30:1 will cause even worse signal out of the antenna, essentially none.  The Radiated power from the coil would be in the picowatts, with more signal radiating from the connection leads.
The measurements by the EEG changing were most likely due to capacitive coupling of the cables leading between the EEG and the coil, and not anything from the brain itself. 
ELF Transmissions require a tremendous amount of power, and ridiculously long antennas to propagate.  A loop antenna isn't of much use below 500kHz, let alone 5-15 Hz.  
In other words, from an engineer:  The information in the link given is incorrect due to interference, with a dose of the experimenter finding what he wanted to find, rather than any actual change in the minds of the very small sample of volunteers.   21:26, 10 July 2010 (UTC)
thread_title:  effects on the brain 

message: Serial Experiments Lain?  I haven't seen enough of the show to know if this is utter fanboy crap, putting this link here.  But it smells strongly of it.  Is it actually discussed in enough detail to warrant inclusion here?
Basically, all the other "see other" links are to radio-related topics.  If someone wants to create a new section for references in fiction, fine, put it together with Tom Clancy.  Until then, screw it I'm deleting it.  
User:Andy_Christ
I think there should be a section on the impact of elf waves on humans. Thats what i was looking for and instead you suggest I look up Tom Clancy??? Well okay duh. Why didn't i think of that?  —Preceding unsigned comment added by 24.113.98.13 (talk) 05:21, 27 June 2008 (UTC)
thread_title:  See also: 

message: There have been some concerns over the possible ecological impact of ELF signals. In 1984 a federal judge... (judge from what country?) 209.124.98.45 21:01, 5 January 2007 (UTC)
thread_title:  Ecological impact 

message: surely not:
"The transmitted signal is often used to track the pig should it become stuck in the pipeline."
118.90.109.249 (talk) 09:35, 4 July 2008 (UTC)
replies: text: Sounds reasonable to me. It's not talking about pigs, its talking about Pipeline inspection gauges (Pig) and Pigging. "Communications are achieved by an extremely low frequency electromagnetic system that performs efficiently in both steel and seawater media. During pigging operations the plug emits a beacon that permits tracking. The accuracy of plug positioning is within +/- 100mm."Subsea Pipeline Solution Pipeline & Gas Journal,  August, 2000. Try googling pipeline pig extremely low frequency for more items. --Dual Freq (talk) 14:26, 4 July 2008 (UTC)
replies: text: I'm considering a rewrite of this sections that is a bit more clear and accurate regarding the application.  I would like to delete the term "Pipeline Inspection Gauge" as it is misleading.  A pig is a vehicle that may or may not include gauges.  The locating function is not just for locating stuck pigs but also for verifying or refining location accuracy of the pigs data.  All of this is made fairly clear in the article on pigging.  The text that I am considering for this paragraph is "Transmitters in the 22 Hz range are also used in pigging. The signal is generated as an alternating magnetic field, and the transmitter is mounted to, or to part of, the "pig". The pig is pushed through a pipeline mostly made of metal. The ELF signal can be detected through the metal allowing it's location to be detected by receivers located outside of the pipe.[31] --Taylor316 (talk) 15:04, 1 January 2019 (UTC)
thread_title:  Can somone verify this? 

message: What about other ELFs? I've added a section that explains ELFs range from 0 to 100 Hz and includes examples regarding hydro electricity at 60 hz. --CyclePat (talk) 16:20, 20 April 2009 (UTC)
replies: text: See Super low frequency for 30-300 Hz. Sometimes the technical use of therms like ELF, UHF etc does not follow closely the 3/30/300 classification. Sv1xv (talk) 16:39, 20 April 2009 (UTC)
replies: text: What is the 3/30/300 classification?  Electromagnetic therapy often uses the term ELF to describe Extremely low frequency.  Some articles on electromagnetic radiation and health also utilize the term. --CyclePat (talk) 22:39, 20 April 2009 (UTC)

text: Is it 3 to 30 ELF, 30 to 300 SLF? Hence 3/30/300? --CyclePat (talk) 22:40, 20 April 2009 (UTC)

text: By 3/30/300 I mean exactly that: LF: 30-300 kHz, MF: 300-3000 kHz, HF: 3-30 MHz, VHF: 30-300 MHz, UHF: 300 MHz - 3 GHz etc. See also :Template:Radio spectrum. Sv1xv (talk) 04:10, 21 April 2009 (UTC)
thread_title:  What about other ELFs 

message: As a first time reader, this article is confusing.  If ELF range is 3-30Hz then why does the article talk about military applications which are actually in the SLF range?  If the 'military speak' doesn't line up with the scientific classification this should be made explicit.
Also the article needs to better explain how we can broadcast in this range if the antenna (in theory) needs to be thousands of kms long... !  It doesn't make this clear at the moment.  There must either be a solution (workaround), or the military actually uses higher frequencies, e.g. SLF or ULF? Amilnerwhite (talk) 23:40, 10 November 2009 (UTC)
thread_title:  ELF vs SLF vs ULF confusion 

message: found a reference for the 3/30  http://lws-trt.gsfc.nasa.gov/trt_liemohn05eos.pdf
and this one categorizes all the bands. http://er.jsc.nasa.gov/SEH/f.html --CyclePat (talk) 07:16, 7 February 2010 (UTC)
thread_title:  reference found for 3 30 

message: Antennas are used to amplify voltage (amplitude) by means of electrical resonance through induction. Any moving electric field will result in a corresponding magnetic field which emanates into free space indefinitely.  An antenna is only required if the threshold of the detection equipment is below the amplitude of the transmitted wave.
As antennas function on the principle of resonance, for a properly tuned antenna, its size needs to be related to the wavelength.  If not, electrical resonance won't occur and the signal will not be amplified.
This is why even small voltage potentials, in the range of 0-500Hz, produce ELF waves.  —Preceding unsigned comment added by 89.241.157.213 (talk) 08:47, 13 July 2010 (UTC)
thread_title: Antenna Length

message: Which kind of antenna will be used there?  — Preceding unsigned comment added by Vakarel (talk • contribs) 18:18, 6 June 2014 (UTC)
thread_title:  ELF-antenna at [[INS Kattabomman]] 

message: The sections on exposure and effects on the nervous system are somewhat mixed up at the moment. I propose one section on exposure, and another on effects on the human body, including potential health effects. Anyone have any problem with such a reorganisation? Jimjamjak (talk) 07:50, 23 February 2015 (UTC)
replies: text: When you say exposure, do you mean standards and legal limits on maximum allowable exposure? --ChetvornoTALK 09:12, 23 February 2015 (UTC)
thread_title:  Separate sections for exposure and health effects 

message: In the "Comparison of international policies on electromagnetic fields" - Table 1: Exposure limits for the general public for electromagnetic fields in inhabited areas in member states of the European Union and selected industrial nations outside the European Union (situation April 2011) [http%3A%2F%2Fec.europa.eu%2Fhealth%2Felectromagnetic_fields%2Fdocs%2Femf_comparision_policies_en.pdf&usg=AFQjCNFLsYCw9VT_vALvnReZscUn5agdIA&sig2=iv0tjzhwYMoARjwGKL5GJg EU emf_comparision_policies_en.pdf] - all EU member states are ranked for their exposure limits for the 50 Hz (ELF), 900 MHz (GSM), 1800 MHz (GSM), 2100 MHz (UMTS).  I think the 50 Hz is mentioned because of radiation coming from powerlines and transformers, isn't it? It drops dead after just a couple of centimeters, and in the transformers to higher voltages afer a coule of 10 cm, but anyway.  --SvenAERTS (talk) 19:07, 9 September 2015 (UTC)
replies: text: Exactly, and there's nothing in the human body that has a preference for certain frequencies. It's not like our hearts start failing at 50Hz, but not at 40Hz or 70Hz. That makes it all the more dubious to study what power-lines and transformers put out there and segment out the frequency of the source. Ooh, that speaker in front of my daughter when she watches a movie on her laptop transmits 5 full Gauss at certain distances and certain levels of audio. How is that being explained away in this WP article? 95.97.55.62 (talk) 11:10, 19 November 2019 (UTC)
thread_title:  50 Hz ? But that's the frequency of the electricity in Europe 

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thread_title:  External links modified 

message: It is not acceptable to make a claim of this seriousness in WP without a reliable source.  It is just scaremongering. Any claims need to be accompanied by field strength figures at least to have any real meaning.Martin Hogbin (talk) 16:41, 21 November 2015 (UTC)
replies: text: Furthermore, it quotes research about RF radiation up to 100 kiloHertz. Well sorry, this could mean they measured leukemia in humans living near FM radio-transmitting antennas (or similar). This leukemia-hype has nothing going for its magnetic fields correlation, and should really be correctly put in WP. This has been further explained (and debunked) in counter-research done to disprove its relation. It's really weird how people claiming 'dangers' from 5G even mix that with magnetic field or lower frequency radiation. They're not the same, and it's not useful if you want to be taken seriously. Perhaps put a link there to the entire spectrum of radio-waves, what's in there, what areas are considered dangerous and at which level/dosage. 95.97.55.62 (talk) 10:47, 19 November 2019 (UTC)
thread_title:  Association with childhood leukemia 

message: A changing EM field will radiate; not much because of the low frequency but then the magnetic field is strong.  The frequency and wavelength are easy to calculate.  The frequency will be 1/22 per year and the wavelength will be 22 ly.  I agree that a source would be good. Martin Hogbin (talk) 09:36, 5 January 2016 (UTC)
replies: text: It's an interesting point, but why is this WP:Notable? --ChetvornoTALK 14:00, 5 January 2016 (UTC)
replies: text: Yes, it represents an extreme wavelength that generated relatively close to us. Martin Hogbin (talk) 18:39, 5 January 2016 (UTC)
replies: text: Similarly, you could mention loudspeakers, for example in a laptop, bluetooth speaker, or studio. Use any Tesla or Gauss meter and see what's actually there. It all disproves the hysteria around magnetic fields being dangerous. Heck, if they were, I was a fan of strong magnets ever since age 5 or thereabouts, I'd be unhealthy as f. now if that were remotely true. I'm age 53 now. No cancer, nothing that could even be pointed to having suffered a lot of magnetic field radiation. Further than that, I have messed with FM-transmitters, built my own, had them in my bedroom for years when I was young, with a growing amount of power (up to 100 Watt FM HF radiation). It did not have any effect whatsoever. Sure, it's an N1 study, but still, if it were as dangerous to DNA as they claim it is, my daughter (now 8) would be a complete retard, which she's not. She skipped a class already. Oh and she loves playing with magnets! 95.97.55.62 (talk) 10:55, 19 November 2019 (UTC)
thread_title:  The solar 22-year magnetic cycle 

message: What I said. It's pretty obvious that we aren't detecting these with 3000 km long antennae. It also seems clear to me that oscillations of a charge (or a magnet?) will create these. In other words (and this is original research on my part), when I rub my feet on a carpet and accumulate a static charge, I am also generating ELF radiation. Am I not? How about spinning electro- and permanent magnets (found in most motors)? This isn't at all clear from this article (for someone who can't read between the lines).Abitslow (talk) 19:14, 11 June 2016 (UTC)
replies: text: Well yes, you nailed it; That's because most of it is hogwash, BS, nonsense, hysteria over tech-phobia. Check how most of the sources that claim dangers are people that haven't finished a physics or tech study in any field. It's the people that can't handle computers, internet, the people that don't understand code, machines, electronics, radio-waves, and because they're so inapt at the field of knowledge, they try and make it a bad thing. So as to no longer have to deal with people telling them they should use internet because it's handy for research, science and progress. "I don't get it, I'm too stupid and lazy to learn new technologies or to operate equipment I don't know, so I'll think of something that makes it bad and unhealthy to use". You see this pattern everywhere now. People conflating the bad of cellphone use, by the people that refuse to communicate with them, etc. "We know it's bad, because we don't use them and we feel fine." 95.97.55.62 (talk) 11:03, 19 November 2019 (UTC)
thread_title:  This article needs a section on Detection and Reception of ELF signals 

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thread_title:  External links modified 

message: Considering the amount of 50/60 Hz power being radiated from country sized "antennas" there is no mention. Seems useless to Conserve 4% when 40% of power fed into the US power grid is used up in the power grid itself. TaylorLeem (talk) 02:12, 29 October 2020 (UTC)
thread_title:  50/60 Hertz powerlines 

message: The article says 
pulsations occurring below ~3 Hz) are considered to lie in the ULF range
The link to ULF says 
300 hertz and 3 kilohertz
Jokem (talk) 00:17, 25 October 2023 (UTC)
thread_title:  ELF vs ULF