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Isn't there a ELF, Extreme Low Frequency ?
Yes, but there doesn't seem to be agreement on the extent of it, so I finally settled for "below 3 kHz." -Palmpilot900
First off BNC is (British Nut Connector or it varies) (and this is most often Video, or in it rg58 form yes RF) The most common connector is a F connector on a RG6 cable vis-a-vis house hold cable or outdoor antenna connection. Not a BNC.
Also need to mention RF radiation. (IE are you getting zapped) RF Engineering.
And the H and vertical elements and magnetic.
(above from anonymous)
I would have to agree with the fellow above, this articule is lacking in many areas. Unlike some people on this discussion board, I feel merging the Radio Frequency page with the Radio Wave page would add confusion to the reader. On the other hand I'd suggest linking the Radio Wave page to the Wave page, because of the Wave Propagation section. After all there are many kind of Waves: Radio, Light, Sound, Energy, Shockwaves, Kinetic, etc. Wave Propagation applies to most/all of them does it not?
Also, some mention or links to the different radio spectrum regulatory commissions (ie: FCC, EU, IEEE, etc) wiki pages would be helpful aswell.
Maybe https://ewhdbks.mugu.navy.mil/freqspec.htm would be of use. ( SEWilco 08:34, 27 May 2005 (UTC))
Entering RF in search goes to RF disambig page, not here, so the RF connectors should be moved there. They really don't belong on this page. -- Blainster 16:27, 14 July 2005 (UTC)
Hello. Can anyone with an interest in this article suggest an article somewhere that might discuss radio spectrum pollution? (More specifically, the problem of radio frequencies overlapping and so on -- I don't know if there are other names for it.) I'm not exactly an expert on the electromagnetic spectrum, but a while ago I thought that the Light pollution article should be disambiguated from non-visual light, because as related as they are on some levels, that article doesn't presently discuss anything other than visible spectrum light pollution. (It's also quite long, and the topics might work better being split anyway.) At the time, I made a stub article called Radio spectrum pollution, but it's been a stub for a while, and I'm wondering if there might be a better place to disambiguate to. Thanks for any help or suggestions. Izogi 04:05, 3 April 2006 (UTC)
Howard6 06:17, 22 March 2007 (UTC) The page exists. There are issues within RF which correspond to light pollution; the main difference is that the main concern in the RF area is the effect the extraneous RF has. The correct term when considering unwanted radio waves would be "Radio Frequency Interference". See interference.
I propose merging this article with radio waves, and suggest that wave radio would be the best title for the combined article. Discussion is at talk:radio waves#Merge.-- Srleffler 01:20, 3 February 2007 (UTC)
Electrumz 05:07, 19 February 2007 (UTC) 05:02, 19 February 2007 (UTC)
I was searching for information regarding RF inductance coils from the inductuction coils page and was lead to this page about radio waves. Perhaps there is not a page for what I was looking for; however, if there was, has it been replaced by this page?
Electrumz
05:07, 19 February 2007 (UTC)05:02, 19 February 2007 (UTC)
Howard6 06:14, 22 March 2007 (UTC) against merge I am an electrical engineer with 30 years experience in RF design and working with radio waves; the two terms have very different connotations even though they sound similar. Amongst the engineering and telecommunications community, "Radio Frequency, or RF" defines a distict field of engineering and in this respect is a bit of a misnomer. "Radio Waves" are only one phenomenon within the broader field of RF. "Radio Waves" refers to the existence of waves in air and space; "RF" also refers to the circuitry which controls and modifies these waves and the existence of these waves within RF circuitry.
what does the "M" in front of the hertz mean?
The wave lenghts are wrong. They are much too big. Check out the formula here in wikipedia under wavelength.
I came to this article for a definition of "radio frequency". Alas, there doesn't seem to be one. Instead, the article is about radio bands, and electromagnetic waves.
In normal usage, does a 500 kHz signal qualify as RF? What about 50 kHz? — EncMstr 22:34, 22 June 2007 (UTC)
Yes and yes.
John
06:02, 2 October 2007 (UTC)
Correct me if I am wrong, but the distinction is in part a matter of engineering techniques used. Frequencies below "radio" are usually called "audio frequency", which puts the low limit of RF at 20 kHz. However, frequencies below 20kHz can be and are used for radio communication. As for the upper end, RF ends and microwaves begin at 300 MHz, but as technology marches on, regular RF techniques are nowadays used well into gigahertz region. Morycm ( talk) 03:06, 3 February 2023 (UTC)
This article used to contain a great deal more information. It was all deleted as a minor edit about six months ago [1]. This is really inappropriate to delete 90% of an article and not discuss it on the talk page AND mark it as minor. I was about to restore it before I realised that most of the deleted information is now in radio waves. Still not sure I shouldn't have just restored it. The editor who did this seems to think that this article should be about radio frequency other than transmissions. I find this a bit odd. I expect to find here information on radio bands - I followed a link that said it was here. The radio waves article I would expect to be on the physics of radio propagation. The table of bands has since been recreated by other editors but there were other tables and several templates were using them. I have fixed the MWband template but there are others. There are also a huge number of incoming links from all over the wiki many of which are expecting information that is not here any more. In short the job was botched and was not by consensus in any case. I propose to reverse the change. SpinningSpark 20:36, 2 May 2008 (UTC)
I know some radio systems operate at very low frequencies, but does "Radio frequency" generally refer to something as low as 3Hz? Could we find a way to indicate a "normal" RF range (i.e. somewhere above the audio frequency range)? I've just linked here from the MRI page, but this page really doesn't indicate quite what I was hoping for. GyroMagician ( talk) 07:39, 3 July 2008 (UTC)
Band name | Common abbreviation | Frequencies | Wavelenghts |
---|---|---|---|
Audio frequencies | (AUDIO) | below 30 kHz | over 10 km |
Radio frequencies | RF | 30 kHz – 1 GHz | 30 cm – 10 km |
Microwave frequencies | μW | 1 GHz – 300 GHz | 1 mm – 30 cm |
Infrared frequencies | IR | 300 GHz – 150 THz | 2 μm – 1 mm |
Near-infrared frequencies | NIR | 150 THz – 385 THz | 780 nm – 2 μm |
Visibile frequencies | (VIS) | 385 THz – 790 THz | 380 nm – 780 nm |
Ultra-violet frequencies | UV | 790 THz – 500 PHz | 600 pm – 380 nm |
X-rays frequencies | X | 500 PHz – 30 EHz | 10 pm – 600 pm |
γ-rays frequencies | γ | over 30 EHz | below 10 pm |
can someone list where in this chart FRS and GMRS is? i think it can be useful for beginners.
thanks —Preceding unsigned comment added by 76.254.10.81 ( talk) 05:09, 22 December 2008 (UTC)
By convention the audible range is 20Hz to 20kHz which only partially covers ELF. Please correct the table text. —Preceding unsigned comment added by 77.70.56.64 ( talk) 18:26, 26 April 2009 (UTC)
I think Radio spectrum should be merged into this article. RS is a terrible article with no references, but there are nearly 100 links to it, so it needs to be fixed somehow. Thoughts anyone? Jonverve ( talk) 21:13, 15 May 2009 (UTC)
the resonant frequency formula needs fixed, the formula should be 1 over 2pi times the square root of L times C, i tried to fix it but idk how to get 1 to go over the entire formula.-- 159.218.81.233 ( talk)
thanks dude-- 159.218.81.233 ( talk) 17:03, 26 April 2010 (UTC)
We appear to have a one-letter edit war. Or a 'k' flashing at a very low frequency! Rather silly. On the one hand, radio waves can most definitely be produced at 3Hz. On the other hand, I don't think any electronic/electrical engineer would define 3Hz as radio-frequency. What should be done? GyroMagician ( talk) 07:34, 31 May 2010 (UTC)
I have reverted an edit by a user which is trying to insert that 1/√LC is only approximate for parallel tuned circuits. Previously reverted by another editor. For a tuned circuit without loss the expression is correct in both cases. The underlying assumption of the edit is that there is a loss due to series resistance of the inductance coil. It could equally be said that tanδ losses in the capacitor dielectric will make the expression inexact for series tuned circuits. Saying one is exact and the other is not is misleading. In any case, I don't think it is helpful to the reader to mention exactness in this particular article - it does not really add anything to the understanding of the subject of the article. At most, a link to an article where the issue is properly explained could be inserted. SpinningSpark 16:52, 8 September 2010 (UTC)
Yes, I agree, that this might not be the correct place to discuss the equations for resonance. But somehow my pedantic side is telling me that you shouldn't publish the wrong equation, so maybe that means don't mention the equation at all! Check your text books guys ... the equation for series resonance does not include R, as follows:
fr = 1/2pi * 1/sqrt(LC}
which is approximately correct for parallel resonance as well, but more accurately given by:
fr = 1/2pi * sqrt(1/LC - R^2/L^2)
In other words, R can shift resonance (albeit slightly, and only in the parallel situation). I rest my case and await your humble apologies!
193.60.63.224 ( talk) 13:02, 9 September 2010 (UTC)
OK, I am going to persevere in the face of opposition. I have a library of 100s of books on radio and electronics, most of them are quite old (like me) and you might laugh, but I trust them! I checked Renton's "Telecommunications Principles" and Langford-Smiths "Radiotron Designers Handbook"; they both agree with my views. Also please see http://hyperphysics.phy-astr.gsu.edu/hbase/electric/serres.html#c2 and http://hyperphysics.phy-astr.gsu.edu/hbase/electric/parres.html The resistance is usually shown as series to the inductor, where it is likely in fact to be the most dominant circuit imperfection.
193.60.63.224 ( talk) 15:34, 9 September 2010 (UTC)
I've just rolled back (most of) several edits. Those edits were largely to do with radio waves not radio frequency, and they are not the same thing. We already have an article on radio waves, and perhaps some of the material can or should be added to that article, if it is not already there. Mitch Ames ( talk) 04:28, 10 April 2011 (UTC)
The Very low frequency article has a table of transmitted signals. 17.5 kHz seems to be transmitting 20 second pulses, but the source is not listed. Is ET trying send a message to Jodie Foster. That article doesn't seem active so I thought I would post here. Is there any info about it to update the table or should I just put Lakeview Cemetery in Ithaca, New York as the source?-- Canoe1967 ( talk) 19:21, 15 June 2012 (UTC)
Hi there,
I was looking that the rf spectrum table and noticed the format of both the frequency column and wave length column do not match
example 3 – 30 MHz does NOT correspond to 10 – 100 m
the author or an editor needs to decide which column should determine the order of magnitude and then match the range in the other column accordingly
example 3 - 30 Mhz, 100 - 10 m (NOT 10 - 100 m)
I'm surprised this boo-boo is both in the article and here in the talk.
I'm going to guess that this is just an oversight because we wouldn't want readers to get confused that small number frequency = small number wave length which is I know that everyone here on this talk page knows is incorrect :-) — Preceding unsigned comment added by 24.6.92.28 ( talk) 21:54, 17 June 2013 (UTC)
Frequency | Wavelength | Designation | Abbreviation [1] |
---|---|---|---|
3 – 30 Hz | 105 – 104 km | Extremely low frequency | ELF |
30 – 300 Hz | 104 – 103 km | Super low frequency | SLF |
300 – 3000 Hz | 103 – 100 km | Ultra low frequency | ULF |
3 – 30 kHz | 100 – 10 km | Very low frequency | VLF |
30 – 300 kHz | 10 – 1 km | Low frequency | LF |
300 kHz – 3 MHz | 1 km – 100 m | Medium frequency | MF |
3 – 30 MHz | 100 – 10 m | High frequency | HF |
30 – 300 MHz | 10 – 1 m | Very high frequency | VHF |
300 MHz – 3 GHz | 1 m – 10 cm | Ultra high frequency | UHF |
3 – 30 GHz | 10 – 1 cm | Super high frequency | SHF |
30 – 300 GHz | 1 cm – 1 mm | Extremely high frequency | EHF |
300 GHz - 3000 GHz | 1 mm - 0.1 mm | Tremendously high frequency | THF |
-- Wyn.junior ( talk) 04:16, 2 March 2014 (UTC)
References
in the paragraph "Thus, under similar conditions of propagation, the higher frequency signal attenuates faster than the lower frequency signal and becomes too weak to be detected at the end of the receiver, located at larger distances. An RF power amplifier is used to amplify the power level of such a transmitter RF Signal, so that it can travel larger distances with less attenuation."
1) the attenuation is independent of power, so higher power creates a higher signal, not less attenuation
2) also, the relation between wavelength and attenuation should be made more explicit (attenuation is per distance, not cycle, so to first order it should also be independent of frequency) Chris2crawford ( talk) 16:34, 14 March 2014 (UTC)
On the 12th of June I posted some comments that have been removed by EncMstr. Again, here are my comments on this article.
1. "High-power exposure to microwave RF is known to create a range of effects from lower to higher power levels, ranging from unpleasant burning sensation on the skin and microwave auditory effect, to extreme pain at the mid-range, to physical burning and blistering of skin and internals at high power levels (see microwave burn)."
This sentence does not make much sense to me. It's either incomplete or it needs to be rewritten.
2. "Additional rational for EMF restrictions is to avoid auditory effect and energy-induced unconsciousness in rats."
I don't understand this sentence. I think it needs to be rewritten.
3. The 3 links under "General RF exposure" should be moved to the "See also" section.
ICE77 ( talk) 04:44, 8 July 2015 (UTC)
I am creating this section to discuss the proposal of Fgnievinski who on 2 February 2019 added a tag to the Radio-frequency current section, proposing to split this section off into a new article named Radio-frequency current. He apparently didn't add any supporting discussion. ---- Chetvorno TALK 20:24, 21 February 2019 (UTC)
@ Wtshymanski:, I don't fully agree with this edit which removed a paragraph which indicated the terms "long wave", "medium wave", and "short wave" are not well defined. Today there might be some standards, but I don't have any of them. Even if the standards do define the terms, I don't believe they were well-defined during the period they were avant-garde and receiving lots of attention. Jc3s5h ( talk) 19:35, 28 February 2020 (UTC)
The usage of RF (which currently redirects here) is under discussion, see talk:RF (disambiguation) -- 64.229.88.43 ( talk) 05:46, 23 July 2022 (UTC)
This is the
talk page for discussing improvements to the
Radio frequency article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
![]() | This article was selected as the article for improvement on 20 May 2013 for a period of one week. |
![]() | This page is not a forum for general discussion about Radio frequency. Any such comments may be removed or refactored. Please limit discussion to improvement of this article. You may wish to ask factual questions about Radio frequency at the Reference desk. |
Isn't there a ELF, Extreme Low Frequency ?
Yes, but there doesn't seem to be agreement on the extent of it, so I finally settled for "below 3 kHz." -Palmpilot900
First off BNC is (British Nut Connector or it varies) (and this is most often Video, or in it rg58 form yes RF) The most common connector is a F connector on a RG6 cable vis-a-vis house hold cable or outdoor antenna connection. Not a BNC.
Also need to mention RF radiation. (IE are you getting zapped) RF Engineering.
And the H and vertical elements and magnetic.
(above from anonymous)
I would have to agree with the fellow above, this articule is lacking in many areas. Unlike some people on this discussion board, I feel merging the Radio Frequency page with the Radio Wave page would add confusion to the reader. On the other hand I'd suggest linking the Radio Wave page to the Wave page, because of the Wave Propagation section. After all there are many kind of Waves: Radio, Light, Sound, Energy, Shockwaves, Kinetic, etc. Wave Propagation applies to most/all of them does it not?
Also, some mention or links to the different radio spectrum regulatory commissions (ie: FCC, EU, IEEE, etc) wiki pages would be helpful aswell.
Maybe https://ewhdbks.mugu.navy.mil/freqspec.htm would be of use. ( SEWilco 08:34, 27 May 2005 (UTC))
Entering RF in search goes to RF disambig page, not here, so the RF connectors should be moved there. They really don't belong on this page. -- Blainster 16:27, 14 July 2005 (UTC)
Hello. Can anyone with an interest in this article suggest an article somewhere that might discuss radio spectrum pollution? (More specifically, the problem of radio frequencies overlapping and so on -- I don't know if there are other names for it.) I'm not exactly an expert on the electromagnetic spectrum, but a while ago I thought that the Light pollution article should be disambiguated from non-visual light, because as related as they are on some levels, that article doesn't presently discuss anything other than visible spectrum light pollution. (It's also quite long, and the topics might work better being split anyway.) At the time, I made a stub article called Radio spectrum pollution, but it's been a stub for a while, and I'm wondering if there might be a better place to disambiguate to. Thanks for any help or suggestions. Izogi 04:05, 3 April 2006 (UTC)
Howard6 06:17, 22 March 2007 (UTC) The page exists. There are issues within RF which correspond to light pollution; the main difference is that the main concern in the RF area is the effect the extraneous RF has. The correct term when considering unwanted radio waves would be "Radio Frequency Interference". See interference.
I propose merging this article with radio waves, and suggest that wave radio would be the best title for the combined article. Discussion is at talk:radio waves#Merge.-- Srleffler 01:20, 3 February 2007 (UTC)
Electrumz 05:07, 19 February 2007 (UTC) 05:02, 19 February 2007 (UTC)
I was searching for information regarding RF inductance coils from the inductuction coils page and was lead to this page about radio waves. Perhaps there is not a page for what I was looking for; however, if there was, has it been replaced by this page?
Electrumz
05:07, 19 February 2007 (UTC)05:02, 19 February 2007 (UTC)
Howard6 06:14, 22 March 2007 (UTC) against merge I am an electrical engineer with 30 years experience in RF design and working with radio waves; the two terms have very different connotations even though they sound similar. Amongst the engineering and telecommunications community, "Radio Frequency, or RF" defines a distict field of engineering and in this respect is a bit of a misnomer. "Radio Waves" are only one phenomenon within the broader field of RF. "Radio Waves" refers to the existence of waves in air and space; "RF" also refers to the circuitry which controls and modifies these waves and the existence of these waves within RF circuitry.
what does the "M" in front of the hertz mean?
The wave lenghts are wrong. They are much too big. Check out the formula here in wikipedia under wavelength.
I came to this article for a definition of "radio frequency". Alas, there doesn't seem to be one. Instead, the article is about radio bands, and electromagnetic waves.
In normal usage, does a 500 kHz signal qualify as RF? What about 50 kHz? — EncMstr 22:34, 22 June 2007 (UTC)
Yes and yes.
John
06:02, 2 October 2007 (UTC)
Correct me if I am wrong, but the distinction is in part a matter of engineering techniques used. Frequencies below "radio" are usually called "audio frequency", which puts the low limit of RF at 20 kHz. However, frequencies below 20kHz can be and are used for radio communication. As for the upper end, RF ends and microwaves begin at 300 MHz, but as technology marches on, regular RF techniques are nowadays used well into gigahertz region. Morycm ( talk) 03:06, 3 February 2023 (UTC)
This article used to contain a great deal more information. It was all deleted as a minor edit about six months ago [1]. This is really inappropriate to delete 90% of an article and not discuss it on the talk page AND mark it as minor. I was about to restore it before I realised that most of the deleted information is now in radio waves. Still not sure I shouldn't have just restored it. The editor who did this seems to think that this article should be about radio frequency other than transmissions. I find this a bit odd. I expect to find here information on radio bands - I followed a link that said it was here. The radio waves article I would expect to be on the physics of radio propagation. The table of bands has since been recreated by other editors but there were other tables and several templates were using them. I have fixed the MWband template but there are others. There are also a huge number of incoming links from all over the wiki many of which are expecting information that is not here any more. In short the job was botched and was not by consensus in any case. I propose to reverse the change. SpinningSpark 20:36, 2 May 2008 (UTC)
I know some radio systems operate at very low frequencies, but does "Radio frequency" generally refer to something as low as 3Hz? Could we find a way to indicate a "normal" RF range (i.e. somewhere above the audio frequency range)? I've just linked here from the MRI page, but this page really doesn't indicate quite what I was hoping for. GyroMagician ( talk) 07:39, 3 July 2008 (UTC)
Band name | Common abbreviation | Frequencies | Wavelenghts |
---|---|---|---|
Audio frequencies | (AUDIO) | below 30 kHz | over 10 km |
Radio frequencies | RF | 30 kHz – 1 GHz | 30 cm – 10 km |
Microwave frequencies | μW | 1 GHz – 300 GHz | 1 mm – 30 cm |
Infrared frequencies | IR | 300 GHz – 150 THz | 2 μm – 1 mm |
Near-infrared frequencies | NIR | 150 THz – 385 THz | 780 nm – 2 μm |
Visibile frequencies | (VIS) | 385 THz – 790 THz | 380 nm – 780 nm |
Ultra-violet frequencies | UV | 790 THz – 500 PHz | 600 pm – 380 nm |
X-rays frequencies | X | 500 PHz – 30 EHz | 10 pm – 600 pm |
γ-rays frequencies | γ | over 30 EHz | below 10 pm |
can someone list where in this chart FRS and GMRS is? i think it can be useful for beginners.
thanks —Preceding unsigned comment added by 76.254.10.81 ( talk) 05:09, 22 December 2008 (UTC)
By convention the audible range is 20Hz to 20kHz which only partially covers ELF. Please correct the table text. —Preceding unsigned comment added by 77.70.56.64 ( talk) 18:26, 26 April 2009 (UTC)
I think Radio spectrum should be merged into this article. RS is a terrible article with no references, but there are nearly 100 links to it, so it needs to be fixed somehow. Thoughts anyone? Jonverve ( talk) 21:13, 15 May 2009 (UTC)
the resonant frequency formula needs fixed, the formula should be 1 over 2pi times the square root of L times C, i tried to fix it but idk how to get 1 to go over the entire formula.-- 159.218.81.233 ( talk)
thanks dude-- 159.218.81.233 ( talk) 17:03, 26 April 2010 (UTC)
We appear to have a one-letter edit war. Or a 'k' flashing at a very low frequency! Rather silly. On the one hand, radio waves can most definitely be produced at 3Hz. On the other hand, I don't think any electronic/electrical engineer would define 3Hz as radio-frequency. What should be done? GyroMagician ( talk) 07:34, 31 May 2010 (UTC)
I have reverted an edit by a user which is trying to insert that 1/√LC is only approximate for parallel tuned circuits. Previously reverted by another editor. For a tuned circuit without loss the expression is correct in both cases. The underlying assumption of the edit is that there is a loss due to series resistance of the inductance coil. It could equally be said that tanδ losses in the capacitor dielectric will make the expression inexact for series tuned circuits. Saying one is exact and the other is not is misleading. In any case, I don't think it is helpful to the reader to mention exactness in this particular article - it does not really add anything to the understanding of the subject of the article. At most, a link to an article where the issue is properly explained could be inserted. SpinningSpark 16:52, 8 September 2010 (UTC)
Yes, I agree, that this might not be the correct place to discuss the equations for resonance. But somehow my pedantic side is telling me that you shouldn't publish the wrong equation, so maybe that means don't mention the equation at all! Check your text books guys ... the equation for series resonance does not include R, as follows:
fr = 1/2pi * 1/sqrt(LC}
which is approximately correct for parallel resonance as well, but more accurately given by:
fr = 1/2pi * sqrt(1/LC - R^2/L^2)
In other words, R can shift resonance (albeit slightly, and only in the parallel situation). I rest my case and await your humble apologies!
193.60.63.224 ( talk) 13:02, 9 September 2010 (UTC)
OK, I am going to persevere in the face of opposition. I have a library of 100s of books on radio and electronics, most of them are quite old (like me) and you might laugh, but I trust them! I checked Renton's "Telecommunications Principles" and Langford-Smiths "Radiotron Designers Handbook"; they both agree with my views. Also please see http://hyperphysics.phy-astr.gsu.edu/hbase/electric/serres.html#c2 and http://hyperphysics.phy-astr.gsu.edu/hbase/electric/parres.html The resistance is usually shown as series to the inductor, where it is likely in fact to be the most dominant circuit imperfection.
193.60.63.224 ( talk) 15:34, 9 September 2010 (UTC)
I've just rolled back (most of) several edits. Those edits were largely to do with radio waves not radio frequency, and they are not the same thing. We already have an article on radio waves, and perhaps some of the material can or should be added to that article, if it is not already there. Mitch Ames ( talk) 04:28, 10 April 2011 (UTC)
The Very low frequency article has a table of transmitted signals. 17.5 kHz seems to be transmitting 20 second pulses, but the source is not listed. Is ET trying send a message to Jodie Foster. That article doesn't seem active so I thought I would post here. Is there any info about it to update the table or should I just put Lakeview Cemetery in Ithaca, New York as the source?-- Canoe1967 ( talk) 19:21, 15 June 2012 (UTC)
Hi there,
I was looking that the rf spectrum table and noticed the format of both the frequency column and wave length column do not match
example 3 – 30 MHz does NOT correspond to 10 – 100 m
the author or an editor needs to decide which column should determine the order of magnitude and then match the range in the other column accordingly
example 3 - 30 Mhz, 100 - 10 m (NOT 10 - 100 m)
I'm surprised this boo-boo is both in the article and here in the talk.
I'm going to guess that this is just an oversight because we wouldn't want readers to get confused that small number frequency = small number wave length which is I know that everyone here on this talk page knows is incorrect :-) — Preceding unsigned comment added by 24.6.92.28 ( talk) 21:54, 17 June 2013 (UTC)
Frequency | Wavelength | Designation | Abbreviation [1] |
---|---|---|---|
3 – 30 Hz | 105 – 104 km | Extremely low frequency | ELF |
30 – 300 Hz | 104 – 103 km | Super low frequency | SLF |
300 – 3000 Hz | 103 – 100 km | Ultra low frequency | ULF |
3 – 30 kHz | 100 – 10 km | Very low frequency | VLF |
30 – 300 kHz | 10 – 1 km | Low frequency | LF |
300 kHz – 3 MHz | 1 km – 100 m | Medium frequency | MF |
3 – 30 MHz | 100 – 10 m | High frequency | HF |
30 – 300 MHz | 10 – 1 m | Very high frequency | VHF |
300 MHz – 3 GHz | 1 m – 10 cm | Ultra high frequency | UHF |
3 – 30 GHz | 10 – 1 cm | Super high frequency | SHF |
30 – 300 GHz | 1 cm – 1 mm | Extremely high frequency | EHF |
300 GHz - 3000 GHz | 1 mm - 0.1 mm | Tremendously high frequency | THF |
-- Wyn.junior ( talk) 04:16, 2 March 2014 (UTC)
References
in the paragraph "Thus, under similar conditions of propagation, the higher frequency signal attenuates faster than the lower frequency signal and becomes too weak to be detected at the end of the receiver, located at larger distances. An RF power amplifier is used to amplify the power level of such a transmitter RF Signal, so that it can travel larger distances with less attenuation."
1) the attenuation is independent of power, so higher power creates a higher signal, not less attenuation
2) also, the relation between wavelength and attenuation should be made more explicit (attenuation is per distance, not cycle, so to first order it should also be independent of frequency) Chris2crawford ( talk) 16:34, 14 March 2014 (UTC)
On the 12th of June I posted some comments that have been removed by EncMstr. Again, here are my comments on this article.
1. "High-power exposure to microwave RF is known to create a range of effects from lower to higher power levels, ranging from unpleasant burning sensation on the skin and microwave auditory effect, to extreme pain at the mid-range, to physical burning and blistering of skin and internals at high power levels (see microwave burn)."
This sentence does not make much sense to me. It's either incomplete or it needs to be rewritten.
2. "Additional rational for EMF restrictions is to avoid auditory effect and energy-induced unconsciousness in rats."
I don't understand this sentence. I think it needs to be rewritten.
3. The 3 links under "General RF exposure" should be moved to the "See also" section.
ICE77 ( talk) 04:44, 8 July 2015 (UTC)
I am creating this section to discuss the proposal of Fgnievinski who on 2 February 2019 added a tag to the Radio-frequency current section, proposing to split this section off into a new article named Radio-frequency current. He apparently didn't add any supporting discussion. ---- Chetvorno TALK 20:24, 21 February 2019 (UTC)
@ Wtshymanski:, I don't fully agree with this edit which removed a paragraph which indicated the terms "long wave", "medium wave", and "short wave" are not well defined. Today there might be some standards, but I don't have any of them. Even if the standards do define the terms, I don't believe they were well-defined during the period they were avant-garde and receiving lots of attention. Jc3s5h ( talk) 19:35, 28 February 2020 (UTC)
The usage of RF (which currently redirects here) is under discussion, see talk:RF (disambiguation) -- 64.229.88.43 ( talk) 05:46, 23 July 2022 (UTC)