User talk:Chetvorno/Archive 2

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Archive 1 Archive 2 Archive 3 Archive 4

Conservation of angular momentum.

Your reversion of my edit was not correct. The current statement is accurate. Increasing angular speed by reducing moment of inertia is what is illustrated in the figure. There is no need to add an inaccurate principle when a perfectly good explanation is already available. Conservation of angular momentum can only occur when the resultant force on the body is a central force--try looking at an engineering textbook instead of an elementary physics text (e.g., Beer & Johnston). Most biomechanics texts also will agree (Robertson, Caldwell, Hamill et al., 2004). When a person is airborne you could use the conservation principle (unless there is a large air resistance or air speed, e.g., parachuting). If you change the image to a figure skater in the air then you could apply the conservation principle. In the text, I added an example of a diver that is more appropriate. Keep up your good work on the article but try to refrain from oversimplifying a complex motion.

Dger (talk) 23:39, 1 October 2014 (UTC)
The only "force" on the skater is the slight drag of her skates on the ice. That is why spinning skaters stand with their feet together, to reduce the moment arm of the drag force - the same reason that balance wheels and gyroscopes have needle bearing. Conservation of angular momentum is what a skating spin is all about. After she begins the spin, there is no drive force on her, so without conservation of angular momentum she wouldn't be spinning at all. Try to refrain from overcomplicating a simple motion. That's a much more common problem with Wikipedia editors. --ChetvornoTALK 01:28, 2 October 2014 (UTC)

Crystal oscillator

Hey Chetvorno, given your interest in horology (and crystal oscillators) I have a project I think you'd find really interesting. Sorry for contacting you here, I couldn't find you elsewhere on the web. You can reach me at kevinrose [at] google (more about me can be found here: http://about.me/kevinrose and here: https://en.wikipedia.org/wiki/Kevin_Rose ) — Preceding unsigned comment added by Thekevinrose (talkcontribs) 05:12, 18 October 2014 (UTC)

Oh, you c

Hi Chetvorno, first a happy and a peaceful new year.

But to my problem. You deleted my remark "component" in the article Crystal oscillator. But have a look, in the article "Crystal oscillator" in all paragraphs the behavior and the parameter of a quartz crystall is described. You can't find any description of an oscillator in this article. The meaning of "oscillator" in this case is not unique. "to oscillate" is here a mechanical behavior of the quartz crystal and has lead in the past to the term "Crystal oscillator" as an oscillating component. The term Quartz crystal has a redirect to Quartz. If you want to describe an oscillator the term Electronic oscillator will be used. I am sorry, but Crystal oscillator is not an oscillator but an electro-mechanical component. It is very much easier in the German language, here the term "Schwingquarz" say directly that the quartz is oscillating (schwingen). If you agree I will add my remark "component" in a few days again. kind regards--Elcap (talk) 13:18, 1 January 2013 (UTC)

This has been discussed before, on the article's talk page. Unfortunately, in engineering usage, the term "crystal oscillator" refers to the circuit, and the resonator itself is referred to as a "crystal" or "quartz crystal", which of course have more general meanings in ordinary usage. The editors who wrote the article have been unfamiliar or have deliberately finessed this; see the citations I added to the article. I've been meaning to bring this up again on the talk page, whether we need a new article, Piezoelectric crystal or Piezoelectric resonator, that would cover the resonator itself, because the bulk of the article is about the resonator. --ChetvornoTALK 15:19, 1 January 2013 (UTC)
Sorry, I never saw the discussion before. If you or someone else can moove the excisting article to "Quartz crystal" or "Quartz crystal resonator" it may be a good solution, because the contend of the article fits for the resonator. --Elcap (talk) 15:35, 1 January 2013 (UTC)
You were absolutely right, the article and its introduction were inconsistent. I should have discussed it on the talk page before reverting you. It was good to bring that up. --ChetvornoTALK 15:45, 1 January 2013 (UTC)

Reversion of Perpetual motion lead rewrite

Really?

1) not wrong - physicist

2) long is not a problem for a long article. the lede covered all the key aspects of the topic IMHO

3) you don't source ledes unless they make statements not covered in the body. all of the information i posted in the new lede was covered in the body.

4) the lede I replaced SUCKED. If you're going to "fix" it, maybe try replacing it with something even better, rather than the horrible confusing mash that was there before.

I leave it in your hands. Maury Markowitz (talk) 19:55, 18 October 2014 (UTC)

I sort of agree with the last point, the current introduction is not the best. Would you mind if I put these comments on the Perpetual motion Talk page, where other interested editors could see them? --ChetvornoTALK 20:23, 18 October 2014 (UTC)

Glow discharge image

RE: Wikipedia:Media copyright questions#Is close paraphrase of a diagram+graph a copyvio?

Hi. I noticed you changed the origin of your image on commons. That's a good thing to do, but I don't know the answer to the copyright question is. Such graphs may be common/obvious, and the data may not be subject to copyright. Apparently many variations of the periodic table are not copyrightable, so it is possible the glow discharge is not either. I just don't know. Glrx (talk) 03:58, 19 December 2014 (UTC)

Thanks for bringing the issue up. It bothered me. I copied the diagram from some old Russian book on the web, and persuaded myself it was out of copyright. But I think we can relax. Works published in the US before 1963 revert to PD if the copyright is not renewed when it expires in 28 years. As I mentioned on the page, I searched the US Catalogue of Copyright Entries for the relevant years for a renewal entry and didn't find it. So as I understand it, unless the diagram was attributed and used by permission from someone else, it's PD. --ChetvornoTALK 04:28, 19 December 2014 (UTC)

Negative resistance

Following your thorough reworking of negative resistance I feel it ought to be nominated as a GA. What do you think? SpinningSpark 20:13, 25 December 2014 (UTC)

Wow. I'd really like to. The article probably needs a cleanup so it meets all the technical requirements. I've never worked on a GA before. You've done a lot of them. Would you be willing to help, or at least consult on it? --ChetvornoTALK 21:39, 25 December 2014 (UTC)
Ok, I've nominated it. Of course I will help, I would not have suggested a nomination if I wasn't willing to do that. I'll keep the page watchlisted and help respond to any review comments that come up. The requirements are at Wikipedia:Good article criteria. I think we are looking pretty good against that, the article is certainly now well-written and comprehensive. One thing that nominations frequently stumble on is compliance with WP:LEAD. Nobody pays attention to that, but reviewers always pick it up. Without reviewing it in full myself, it looks ok at a glance but it would still be worthwile checking through that every major heading is summarized in the lead and that it does not contain stuff that is not discussed in the article. The technicality of the article and its ease of understanding to a general reader is bound to get some comments, but its probably best to deal with those as they come rather than try to pre-empt them. For those of us familiar with the material it is very hard to judge what outsiders are going to find difficulty with and what they see as obvious. It also depends a great deal on who we get as a reviewer. SpinningSpark 23:47, 25 December 2014 (UTC)
PS, put Talk:Negative resistance/GA1 on your watchlist, that's where the review will go. But don't write anything on the page yet, if you do that you will fool the GA bot into thinking we are no longer looking for a reviewer. SpinningSpark 00:00, 26 December 2014 (UTC)
Thanks, looks good. I'll look at the lead. Do you think ARTICLE SIZE will present a problem? Although the "readable prose" size is a reasonable 40k, the total article size is 531k, far over the 200k recommendation. --ChetvornoTALK 00:26, 26 December 2014 (UTC)
The GA requirement is that it "stays focused on the topic without going into unnecessary detail". There is no length requirement per se, so it shouldn't be a problem. It may mean we have to wait a long time for a reviewer to take an interest in it though. It's going to be hard work for someone to review it. It would be possible to split if we wanted to, both "negative differential resistance devices" and "negative resistance from feedback" could be spun out into their own articles reasonably cleanly. SpinningSpark 01:23, 26 December 2014 (UTC)
I hope it doesn't come to that. My feeling is that the different categories of negative resistance are so confusing I'd like to see them treated together in a single article. My personal preference would be to split off "Negative resistance oscillators" and "Negative resistance amplifiers". But we can take another look if the issue comes up. --ChetvornoTALK 02:55, 26 December 2014 (UTC)
Whatever gets split out, it would still be necessary to leave a summary behind. SpinningSpark 11:52, 26 December 2014 (UTC)

Tetrode

Hi - I have recently completed a major revision of this page, and am hoping that someone will review it so that I can judge what standard I have achieved. Could you have a look ? G4oep (talk) — Preceding undated comment added 18:36, 5 January 2015 (UTC)

Thanks for asking me. I contributed a little bit to the introduction of that article a while back, but I didn't really pay attention to the body so I don't really feel "biased". So I'm not completely "fresh eyes", but if you don't mind that I'd be glad to review it. --ChetvornoTALK 19:22, 5 January 2015 (UTC)

Many thanks. I have added several more pix since yesterday. I am not certain how to go about the proposed merger with 'Beam Tetrode'. G4oep (talk) — Preceding undated comment added 13:07, 6 January 2015 (UTC)

Hi Chris...

We seem to have very similar interests, judged from the fact that we keep bumping into each other in many different contexts. I must say I like your style even though we sometimes don't agree - tho we mostly do. I would like to thank you for looking at the Tetrode page, which I have been editing. Would you like to take a peek at the Tetrode Talk page ? I am using Tetrode as a tool for honing my editing skills and although I am running out of ideas for how to improve it further, it seems that there is still a lot to be done to raise it to a good standard. I am interested in finding out exactly what is required. I have asked for my User Page to be deleted, because it attracted some personal abuse, and I am not happy to reinstate it. But if you would like to know something of my interests just google G4OEP. Btw - I am a retired Senior Lecturer from the University of the West of England (Applied Science Faculty), so I have a strong interest in, and loads of experience of teaching. G4oep (talk) 10:51, 12 January 2015 (UTC)

Yes, I'm sorry, I said I would review the article and then I got involved in other editing and didn't do it. I'll look at it right now. Just at first glance, it looks like you have added a lot of valuable historical material and introduced a needed distinction between the different types of two-grid tubes. It is good to have knowledgeable people like you editing the elect. eng. articles, as some of them seem to have been written from a fairly amateur perspective. Give me an hour or two and I will put my review on the Talk page. Cheers. --ChetvornoTALK 00:08, 13 January 2015 (UTC)

Thanks for you comments G4oep (talk) 09:27, 14 January 2015 (UTC)

Thanks for you very detailed comments on 'Tetrode'. I greatly appreciate the trouble you have taken to make clear what is needed there. Prior to reading that material I had given up, feeling that there was no way that I would ever understand what Wiki users look for in an article. I was beginning to become impatient. Amusing though it might seem now, I really misunderstood "accessibility" (which, to me as a native English speaker, means attainable, approachable, within reach, available, on hand, obtainable, etc"). You have revealed that it is a wikipedia jargon word which, ironically, seems to mean "plain and understandable language", and has nothing to do with my anxiety about references of questionable availability ! This all helps! Your comments have given me plenty to think about. I am just hoping that my enthusiasm for this project will return ! Thanks again - you have really worked at it, and I appreciate that. G4oep (talk) 10:39, 17 January 2015 (UTC)

GLPeterson

I would go ahead and cut back the excessive Tesla material at Wireless power. If GLPeterson reverts we take it from there. The editor's unresponsiveness (including posting Neil Armstrong quotes instead of replying on his talk page) has brought us to WP:DISRUPT, in fact we are way down the flow chart at WP:DDE (at the level of ANI). It all may go nowhere from here, his MO in the past seems to be to push the Wikipedia process as far as he can before sanction and then vanishing for a while. Fountains of Bryn Mawr (talk) 20:00, 23 October 2014 (UTC)

Sorry for the delay. No, GLPeterson is not holding me back. It is just taking me a while to get up to speed on Tesla and his World Wireless ideas. I haven't done much reading yet, maybe you could suggest sources. I was hoping to find a modern RS that would give an engineering assessment of Tesla's ideas. Carlson's book looks good, but I don't have a hard copy and the most relevant sections are blocked on Google Books. --ChetvornoTALK 10:15, 28 October 2014 (UTC)
Just an FYI, I posted an ANI on the editor in question. Fountains of Bryn Mawr (talk) 01:39, 6 December 2014 (UTC)
He also has a Wikipedia:Fringe theories/Noticeboard WP:FTN complaint against him.
I brought a ANI edit-warring complaint against him... --ChetvornoTALK 02:39, 14 December 2014 (UTC)
...aaaand he got a 48 hour block. --ChetvornoTALK 02:39, 14 December 2014 (UTC)
[New Person's Comments] Chetvorno and Roches, I would like to point out a third method of wireless power transmission that does not use magnetic or electric field coupling (in the conventional sense) but instead uses the phenomenon of standing waves to create a "coupling" between a surface and a receiver. The recently published article is free to download and can be found here: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9464494&fulltextType=RA&fileId=S2052841814000098
At first glance it would appear to be similar to the unipolar capacitive method except that the receiver is not connected to ground with the return path being through stray capacitance with a terminal of the receiver. It is also operated at low voltages instead of the high potential required with capacitive methods. Why this is important to earth transmission is that we have developed a modified version of this that allows the localized surface of the earth to be energized. Though we have not yet published these results, and so do not expect them to be mentioned on Wiki, I would like to take the time to agree with Gary in that the conduction method of power transmission is a real theory that is in-fact extensively used in modern Geophysics - at least how I understand this conduction method which does not involve plasmas. There is older literature supporting the conduction method for communication purposes which can be found in Radio Engineering Principles 1st ed., McGraw-Hill Book Company, 1919, by H. Lauer and H. Brown pages 94 through 101. Many radio books from the same time period will give mention to this "conduction method of radio communication." As started, these techniques are highly used in modern magnetotelluric geophysics to determine soil properties. The reason, however, as to why power is not sent using the same techniques is that geophysics focuses on non-resonant signals with EM theory based on radiative fields and traveling waves (which is important for soil layer identification). When non-radiating, resonant techniques are used, such systems can be adapted to something very similar to our single-contact method - again I realize that this statement of mine is not yet published so you can take it with a grain of salt. What I do ask is that you maintain the "Conduction theory" of power transmission as there are older sources describing the technique which was used extensively during WW1 as a quick means of communication. When reviewing Tesla's works, many of his claims and even the Colorado experiment (having two different grounding locations) very much elude to something similar to the "conduction method of radio". Many thanks, Charles [CW Van NesteTALK] 12:15, 59 December 2014 (UTC)
Are you Gary Peterson? --ChetvornoTALK 20:50, 17 December 2014 (UTC)
Roches comments here should be noted because they are a good boil-down of what Wikipedia includes in an article.
  • Wikipedia is an encyclopedia of things that exist. Something described as "elud(ing) to something similar" is not a thing.
  • Wikipedia is an encyclopedia that demands secondary sources to prove something exists.
  • Wikipedia is not a publisher of original thought - If you have completed primary research on a topic, your results should be published in other venues, such as peer-reviewed journals, other printed forms, open research, or respected online publications. Wikipedia can report your work after it is published and becomes part of accepted knowledge; however, citations of reliable sources are needed to demonstrate that material is verifiable, and not merely the editor's opinion.
  • An observation of what Tesla's apparatus seems to look like and how it may have functioned would not be usable.
  • A 1919 source may simply be wrong.
  • A WW1 communication technique is not a wireless power transmission technology (the topic of the article).
  • "Single-contact transmission for the quasi-wireless delivery of power over large surfaces" looks promising. It may have nothing to do with Tesla. Tesla was working at short ranges with no scientific verification so anything could have "lit his bulbs". Also Tesla was claiming a system that could energize the planet Earth, this paper shows a system that could energize a "conference table". In other words, when this paper shows up in a few scientific journals or maybe a text book it will be ready for Wikipedia.
Fountains of Bryn Mawr (talk) 22:27, 17 December 2014 (UTC)
Not to mention that there was no such thing as the "conduction method of radio communication" or "conduction theory" in historical wireless literature. The only person who used that phrase was GLPeterson. --ChetvornoTALK 22:48, 17 December 2014 (UTC)

FYI this has been filed using your contributed material [1]. Fountains of Bryn Mawr (talk) 00:02, 20 January 2015 (UTC)

I noticed smarter minds (than mine) have thought about this already...

On The Media: Over the last several months, Craig Silverman, author of Poynter’s Regret the Error blog, has been tracking the way rumors and unverified claims spiral through the news. Uncorrected Rumors (transcript)

"When deeply held views are challenged, our instinct is not to say, "well let me understand your point of view on this", it's to double down on those beliefs and to reject what's being told to us. And this is one of the reasons why debunking is so difficult. Another reason is that when you're the debunker, you're almost like a spoilsport. You're kind of ruining a joke, especially when it comes to an entertaining story. A lot of research has found that what you actually have to do, is tell a causal narrative, saying actually here's why this is what happened, and when you do that people can replace that misinformation with the new narrative in their mind."

So, replacing a series of unverified claims with a referenced causal narrative showing what really happened can lead to that. Fountains of Bryn Mawr (talk) 23:12, 5 April 2015 (UTC)

Wow. So the Topsy killing got retroactively included in the War of the Currents, even though it occurred 10 years after it was over? How did you discover it? Was it Silverman who found the error? That quote is pretty good. Those who correct inflated claims about Tesla do seem to be regarded as "spoilsports". --ChetvornoTALK 18:19, 6 April 2015 (UTC)
Silverman may have covered this, not sure. I noticed the error because of two facts I learned editing Wikipedia: this was 10 years after the war of currents, and Westinghouse and GE (Edison's old company) were sharing patents in 1903. There was no reason in 1903 to prove Westinghouse was using an unsafe system, it was, for all intents and purposes, GE's system. The rewrite of the article was simply stating the whole story in chronological order. Fountains of Bryn Mawr (talk) 19:28, 6 April 2015 (UTC)

Hughes

This in retrospect looks like a comment on your edit but was not intended that way. I was actually trying to correct the lead "first working radio communication system" and fumbling around for a more descriptive section title. Good catch btw, haven't been watching this article but knew it was a bit of a povfork from Invention of radio. Decided to do "future cleanup" now. Fountains of Bryn Mawr (talk) 21:42, 8 April 2015 (UTC)

I understand, I just changed that section title in passing. Your cleanup looks excellent; the assertion that Hughes created a "radio communication system" is clearly hyperbole. Sarkar says Hughes "failed to invent radio". I don't know about the crystal detector claim. To read the previous version, you would think that Hughes was a combination of Edison, Marconi, and William Shockley. I found some old drawings of Hughes' microphone apparatus that I'm uploading. I was going to add them to the article and maybe expand on his microphone research a little.
It's interesting - as you noted in the article, there is this continuous thread of research into "imperfect contacts" by 18th century scientists, that leads from the microphone to the coherer to the crystal detector (this is not to say that Hughes should be credited with the crystal detector). Some of the early coherers were called "microphone" detectors. --ChetvornoTALK 23:42, 8 April 2015 (UTC)

Tesla

I am not sure if you were directing to me regarding civility on that talk-page, but I guess you probably were cause this was one of rare occasions I really lost all good-faith towards an editor. You may not know, but that same user has been persistently been wanting to add more Croatia to the article for 2 years now. I simply have no patience anymore for nationalistic POV-pushers anymore. First it all started by him wanting to add how Tesla was born in Croatia (he was born in Military Frontier, Austria), then he wanted to change to Croatian-American scientist, now he is basically making fun of this entire project by claiming there were some local citizenships within Austro-Hungary and that if people of the Hungarian part of A-H empire didn't had Hungarian nationality they probably have Croatian one, but all of this without any source talking anything about actually Tesla having it. So I don't think you see the amount of obsession one has to have to ignore all and everything and to want to say Tesla had Croatian citizenship only based on assumptions and then accusing everyone else of being anti-Croatian for dismissing his proposals. Sorry but it is so ridiculous, I dare to sa we are facing a Croatian nationalist teenager who is making fun and making everyone loose time here. Honestly, I was wishing that he reported me for saying "fuck" so I could provide him a boomerang so we could end this madness at Tesla article once and for all. Best regards, FkpCascais (talk) 19:15, 31 May 2015 (UTC)

I agree, he seems to be a WP:POVPUSHer and disruptive editor. The way to deal with him is not give him what he wants; an argument, a dialog. He can't do anything permanent to the article without consensus. If he repeatedly changes the article he can be charged with edit warring. For disruptive editing short of that, or messing with the Talk page, there is a flowchart in WP:Disruptive editing; an ANI complaint can be brought against him. But it's important not to get sucked into disruptive behavior yourself, it's not worth getting charged yourself. Detach. I'm sure he'll argue with you on the Talk page as long as you want to continue. --ChetvornoTALK 19:47, 31 May 2015 (UTC)

Gain edit

Chris, at Gain I changed your edit of Sep. 28, 2012 as per here. Let me know if you disagree with any of the changes. "Mean radiation intensity from an antenna" and "radiation intensity from an isotropic antenna" are synonymous so your "isotropic" is not the issue, only "lossless" = 100% efficient which you omitted. Re the change from receiving to transmitting, the definitions are customarily given for the latter. Vaughan Pratt (talk) 06:15, 10 June 2015 (UTC)

A barnstar for you!

The Tireless Contributor Barnstar
I, Maslesha, as a Wiki member and contributor, hereby wish to thank You, and then thank You again, and thank You once more, for your diligence and effort in making the Wikipedia a better, less biased, and more reliable resource than any other resource people around the world can use. It is equally a surprise and a true honor to find such a dedicated and unbiased author, from which the Wikipedia can only expect to flourish. Live long and prosper! :) Maslesha (talk) 23:10, 7 July 2015 (UTC)

Thank you so much! I've never gotten an award on WP, I've always toiled in obscurity. :) --ChetvornoTALK 14:01, 9 July 2015 (UTC)

Your concerns

I am sorry to have caused you so much concern. Please see new thread at Wikipedia talk:Good article nominations. Thanks. • Lingzhi(talk) 03:19, 11 July 2015 (UTC)

Sorry this is taking so long. If I had had experience with the process, I would have cleaned the article up more before I let Spinningspark nominate it. I respect your high standards. --ChetvornoTALK 16:14, 11 July 2015 (UTC)
Sorry I've given you so much trouble! And thank you for the kind words. • Lingzhi(talk) 23:19, 11 July 2015 (UTC)

negative resistance

  • Seems you're editing now. I'll leave it alone. many many refs need to be thinned... Cheers. • Lingzhi(talk) 12:14, 9 July 2015 (UTC)

Replacing URL with archive

The usual practice is to retain the url of the original site and have the archive as an additional link, not remove the original altogether as you did here. Personally, I add the archive manually (example) but it can also be added in the cite template using the archive-url= and archive-date= parameters. One sets dead-url=no to tell the template that the original link still works and should be used rather than the archive. If the link goes dead in the future, then change to dead-url=yes. SpinningSpark 13:51, 16 July 2015 (UTC)

Okay, I'll change them. --ChetvornoTALK 14:25, 16 July 2015 (UTC)

I really like the cleanup and expansion. The article makes allot more sense now. Fountains of Bryn Mawr (talk) 15:22, 21 December 2014 (UTC)

Thanks, but better reserve judgment. I'm not done yet. You might hate it before I'm through :) --ChetvornoTALK 15:30, 21 December 2014 (UTC)

I also appreciate your efforts to make the article on wireless power more understandable for the general audience, and I also like your clean-up. However, many researchers into the subject, most notably in the Japanese JAXA and NASA in the US, were left out. I am sure you'll be able to find them after searching the relevant published papers databases. My issue here is that Dr. https://en.wikipedia.org/wiki/Marin_Solja%C4%8Di%C4%87 and his company, https://en.wikipedia.org/wiki/WiTricity were given an undue amount of attention, almost like an advertisement(!) as if he (and his company) were at the forefront of the wireless energy transfer research. In reality, their results were no better than those of the other researchers. There were no breakthroughs made by Soljacic's experiments, so I believe he should be mentioned, but not so ostentatious, as if the others didn't contribute to the field. — Preceding unsigned comment added by Maslesha (talkcontribs) 22:55, 7 July 2015 (UTC)

Sorry about the delay. Well, I think you are right. Wireless power was a hot new field in 2007, and although as you say their work wasn't a breakthrough, those MIT professors got a lot of attention in the mainstream press and "rode the wave" of publicity. What would you take out of the article and what would you put in? --ChetvornoTALK 14:01, 9 July 2015 (UTC)

I believe Mr. Soljacic, and his company, should be mentioned no more than once. He deserves to be mentioned, but not as a "leader" in the field. Rather as a contributor, among many others. Any more than that would, imho, constitute an advertising. Unless his team manages to do something exceptional, his contributions are about at the same level as the previous art. Thus, at this point, I'd recommend a "trim" of the article, and to keep it at that, until something noteworthy appears.

Would you mind very much if I moved this discussion to Talk:Wireless power and continued it there? Since it concerns that article this would give other editors a chance to comment. --ChetvornoTALK 05:44, 25 July 2015 (UTC)

Crystal radio

I believe this is incorrect: "A semiconductor crystal (detector) which extracts the audio signal (modulation) from the radio frequency carrier wave."

The diode only rectifies the voltage. It does not extract the audio part.

If the frequency of the applied voltage to a diode is 100,000 hz , the passed frequency will be rectified but at the same frequency, 100,000 hz.

The extraction of the audio frequencies from the rectified carrier frequency takes place in the headphones, which are of an electro-mechanical nature and are made to respond to 10 - 10,000 hz. The 100,000 hz carrier frequency can drive the earphone but it can only respond at audio frequencies. They cannot respond at 100,000 hz.Zedshort (talk) 00:22, 22 August 2015 (UTC)

Or more likely at the bypass capacitor across the headphone terminals that passes the carrier to ground, or the capacitance between the conductors in the headphone cord. Regardless, it is the nonlinear action of the diode that produces the baseband (audio) component. The spectrum of the signal before rectification consists of a carrier with sidebands, no audio frequencies. The spectrum of the rectified signal has the audio component in it. It also has carrier frequencies, but since we can't hear them that is not important. The low-pass action of the headphone driver is not really necessary; if the headphones could reproduce 100,000 Hz we would still hear the audio. Putting it in simple terms for the general readers who will be reading this section: the diode does extract the audio from the radio signal. --ChetvornoTALK 01:35, 22 August 2015 (UTC)
I was referring to the design of crystal set that consists only of an antenna, coil, diode, and ground. There is nowhere in that part of the circuit that the audio signal is "extracted." That part of the circuit only tunes out other frequencies and lets pass the desired frequency (100 khz). The audio is implicit in the waveform of the carrier frequency, rectified or not. Tuning in of a particular frequency takes place in the combination of antenna, and coil (with its inherent capacitance) and nothing more. The diode only rectifies the carrier voltage (perhaps 100 khz). The "extraction" of the audio signal from the rectified carrier wave takes place in the headphones as their nature makes them incapable of responding at the carrier frequency but able to respond to only at 10-10,000 hz. The audio waveform is not reproduced as a voltage anywhere in the system. It is implied, but it does not exist. Zedshort (talk) 15:50, 22 August 2015 (UTC)
There are no audio frequencies in the circuit before the diode, only radio frequencies. The rectifying action of the diode is what generates the audio frequency components. It can be proved mathematically. And the audio component certainly does exist; the concept of separate frequency components making up a composite signal is essential to the understanding of crystal radios. A bypass capacitor across the headphone terminals shows the audio signal exists; it removes the carrier pulses, leaving the audio signal "reproduced as a voltage" in the headphone wires. And even if the carrier was not removed and the earphone was able to reproduce it, we cannot hear 100 kHz sounds so the radio would sound the same. The fact that it doesn't matter whether the carrier is removed by a bypass capacitor, by the headphone inductance, or not at all, shows that the carrier removal is not the important part of the process. It is essential for introductory readers to understand that it is the diode which demodulates the signal, "translating" the modulation from the sideband (radio) frequencies to the baseband (audio) frequencies. --ChetvornoTALK 17:39, 22 August 2015 (UTC)
Sorry, I'm still not sure we are on the same frequency on this. Please consider reading this: http://www.crystalradio.net/crystalplans/xximages/crystal_receivers_for_broadcast_reception.pdf
It is dated, but it is one of the best expositions on the subject from the early days of radio. BTW, about the capacitor across headphones. Is that a result of using a piezo type earpiece vs a old fashioned coil type? Zedshort (talk) 02:18, 23 August 2015 (UTC)
Well, I agree, it does look like a good explanation of crystal radios generally. I think it could be used as a source in the article. However, it was written for a less technological age, and the explanation of the detector has been simplified to the point where it is incorrect or incomplete. "In order that the received currents should traverse the telephone, it is necessary that they be 'rectified', or turned into a current that is proceeding in one direction only." This isn't true, the earphone does not require current "in one direction", and the explanation misses the point of the rectification.
Did you read the box on how the diode works in the Diode section of the article? Although short it is a pretty good explanation. The graphs from the article are at right. Graph (A) shows the AM radio signal voltage from the coil applied to the diode. The rapid cycles are the carrier frequency, while the slow undulations of the height are the audio signal. If this voltage was applied directly to the earphone, no sound would be heard. Each cycle of the carrier would push the earphone's diaphragm back and forth. The frequency of the carrier pulses themselves is far too rapid for the earphone diaphragm to follow, but this is not the reason that no sound is produced. The reason is that the slow audio variations, which is what we want earphone to respond to, are on both sides of the wave. When the amplitude of the positive half of the wave (above the axis) increases, the amplitude of the negative half (below the axis) increases just as much. Therefore the two opposite pushes on the diaphragm each cycle cancel out, the average value of the wave is zero, and the audio variations cause no net motion of the diaphragm. In electronics you say that the waveform has no audio frequency component.
In order for the sound to be reproduced it is necessary for the diaphragm to move in one direction as the amplitude of the wave increases, and the opposite direction as the amplitude decreases. To do this the diode rectifies the wave (B), removing half of each carrier cycle. The rectified wave does not average zero, its average value varies with the audio, that is, it has an audio frequency component. If this is applied to the earphone the average force of the pulses on the diaphragm will vary with the slow audio undulations. The diaphragm can respond to these audio frequencies, and moves in and out, producing sound. But this was only possible because the audio frequency component was present in the voltage applied to the earphone, which is due to the diode. --ChetvornoTALK 07:14, 23 August 2015 (UTC)
Yes, we are on the same frequency. But one point please. The middle figure that sketches in the time varying voltage at the peaks of the carrier frequency does not exist anywhere in any part of the radio. That line is suggested by the minds-eye and does represent the audio waveform. It should have been sketched in as a dashed line (oops it is). My point is that if you should attach an analyzer to various points in the circuitry you would not find that "smoothed" wave form anywhere. The line represents what the electro-mechanical device, known as an earpiece, can reproduce given the very rapid pulses of uni-direction current to which it is subjected and its slow response. As I said, the earpiece is in effect acting as a second form of filter, the first being the inductance and capacitance of the circuitry. Thanks much. Zedshort (talk) 16:49, 23 August 2015 (UTC)
Sorry, didn't mean to bloviate. I do take your point that the rectified waveform (B) is not the same as the audio (C). You're right, if there is no bypass capacitor you would not find the plain audio waveform anywhere in the circuit. --ChetvornoTALK 20:20, 23 August 2015 (UTC)
I'm pretty sure that the audio wave form exists nowhere in any part of the circuitry regardless of the design, bridging capacitor or no. That is the point that I think should be made. The assumed waveform outlined by the peaks of the carrier frequency only exist in a pseudo form. That audio waveform exists as an output of the speakers as that is the response that they have to the pulsating, rectified carrier current/voltage.Zedshort (talk) 21:18, 23 August 2015 (UTC)

No, with the bypass capacitor the pulses of carrier current are bypassed to ground and the voltage across the capacitor applied to the earphone is the pure audio waveform outlined by the peaks (curve C). The capacitor acts as the filter instead of the earphone; that's it's only function. The pulses of current from the diode charge the capacitor up to the dotted line and the capacitor voltage follows the slow audio variations, "smoothing" the carrier variations out. --ChetvornoTALK 00:23, 24 August 2015 (UTC)

Here are some supporting sources that it is the diode that produces the audio, not the earphone:

The circuits they are talking about are active circuits not passive. I was trying to keep it very, very simple and to talk about the simplest of crystal radios that are completely passive. They have no local oscillators or amplification.

Zedshort (talk) 20:26, 24 August 2015 (UTC)

From that source: "The diode detector separates the carrier from the audio, and allows the voice or music to be heard." No it does not. The diode is nothing but a rectifier that trims off half the voltage and leaves a pulsing direct current. The use of the term detector is highly misleading and should have never been used as it is the RLC tuner that "detects", or allows to pass, the desired frequency and rejects all the other frequencies. Simply because a thousand other people have these misconceptions in their head and presents them online or even in printing does not make them correct.Zedshort (talk) 20:26, 24 August 2015 (UTC)
"...semiconductor diode had not been invented, so extracting the audible modulation signal from the transmission..." And again a misperception. The galena crystal contains a crystal that can rectify the AM frequency and nothing more. It does not extract anything.

Note none of these references give any role in demodulation to the earphone or speaker except translating the audio signal to sound; some don't even mention it. --ChetvornoTALK 00:23, 24 August 2015 (UTC)

Well, I could go on and on, but the point is that people are sloppy in their expressions and many have misconceptions of how the simplest of passive radios work. I apologize if I wasted your time. I may be completely wrong, but will come to understand this completely some time soon. At which time I will travel the amature radio league circuit and place bets with those "experts" as to how such a device works and clean them out IF I AM CORRECT. thanks for your time Zedshort (talk) 20:26, 24 August 2015 (UTC)
If you do, let me know; I'll put my money on your side. I wouldn't bet against someone with your persistence. By the way, I wanted to say I came across your work on the Entropy article a while ago. I won't say I understand it; I'll never get those thermodynamic variables, but it was a lot clearer to me after your rewrite. Thanks much. All the best. --ChetvornoTALK 17:59, 25 August 2015 (UTC)
I am actually considering investing in an analyzer and other such equipment so I can investigate this in a rational manner. I work very hard at improving the expression of ideas here on WP. Of course I am careful to not stray to far from my field of "expertise." I guess it is time to review the electronics that I supposedly learned thirty years ago. There is still much work to be done on WP technology articles. Zedshort (talk) 16:47, 26 August 2015 (UTC)

Some apologies, I didn't notice your edit[2] just before mine, please excuse the term "bogus". I saw the text, thought it was old material, wondered how I missed it, and reworked it. I have been working on related articles and ID'ed the "Fred Peterson" involved as Frederick Peterson, a neurologist who does not seem to have a connection with Edison but does have a continual connection with Columbia University, where Brown's dog demo's were done. Also several sources show the electric chairs invention and final design was by Southwick and company (Fell). The Edison/Brown roll was to finalize the "AC or DC?" question and how much voltage (they pushed AC... go figure ;)). There could be a real Peterson/Brown/Edison connection here, they were all a little too "buddy-buddy" but need a ref on that. Fountains of Bryn Mawr (talk) 16:14, 24 August 2015 (UTC)

No problem; considering the incompleteness of my information, it looks like "bogus" was a pretty good description. Was doing some "drive-by editing" and thought I'd add something about the contributions of Edison, so I just used the first source I came to: Death, Money, and the History of the Electric Chair, on about.com. Should have known better than to trust some unsourced web essay. If I had remembered that you had worked on this subject I probably would have asked you to take a look at it.
It looks like you pretty much dismiss the influence of Edison's anti-AC campaign on the adoption of electrocution in the U.S. If that is true, why is the U.S. virtually the only country in the world to have used electrocution for capital punishment? --ChetvornoTALK 17:12, 24 August 2015 (UTC)
The answers are pretty well laid out in the War of Currents article... oh wait... no it isn't, its all in my head!!!!
Simple answer to your 2nd to last question is that electrocution was under development for 7 years (1881-1888) and signed into law on June 4, 1888. The war of currents (Brown's shenanigans) began on June 5, 1888 (with his angry newspaper letter). So the adoption of electrocution was actually before the War of Currents.
Why did the US adopt the chair?.... that's a good one. I see some answers at Capital punishment in New York, and I saw further text on how New York was on the verge of abolishing capital punishment..... governor David B. Hill railroaded the electrocution bill through to end run the abolitionists but he did not think the legislature would stay with him for long.... he had to quickly get the chair up and running and prove it worked.
BTW feel free to leave notes on this, I am actually up to the "chair" part and was fixing Wikipedia from the "outside in". Needs more work. Fountains of Bryn Mawr (talk) 19:26, 24 August 2015 (UTC)
Yeah, now I remember I noticed the discrepancy in the dates, that NY made its decision before the war was underway. Americans seem to have quite a history of finding new ways to kill people (Colt revolver, Gatling gun, precision bombing, napalm, nuclear weapons, neutron bomb, drones,...), and we like to try them out.
I glanced at your draft article. That's massive. Looks a lot more comprehensive than the current one. When I get a chance in the next couple of days I'll read it through. --ChetvornoTALK 00:26, 28 August 2015 (UTC)

2015

The Tireless Contributor Barnstar
For your large contributions to knowledge of Tesla coils and all things that "resonate". Fountains of Bryn Mawr (talk) 14:12, 27 August 2015 (UTC)

Thank you very much! Although I have to admit that in my case the word "tireless" translates to "unemployed". --ChetvornoTALK 18:02, 27 August 2015 (UTC)

Digital signal definition in analog signal

Hi Chetvorno, I noticed you defined digital signals in analog signal. I've extended and hopefully clarified your definition, and I would be interested in any comments you might have on that.

There's been some question about what a digital signal really is over at Talk:digital signal, and there's been a proposal to turn it into a disambiguation page. I thought you might be interested in the discussion.GliderMaven (talk) 07:49, 7 September 2015 (UTC)

Current wars

No longer in my head[3]. Fountains of Bryn Mawr (talk) 03:50, 8 September 2015 (UTC)

Not totally

You checked in this note in Sentinel "The term "Crazy Ivan" refers to a submarine maneuver and has nothing to do with missiles". That is not true, the term was used to describe rouge launches. I have added a ref to demonstrate this. Maury Markowitz (talk) 12:46, 16 September 2015 (UTC)

Okay. What I was mainly concerned about was, if military jargon is used, it needs to be explained. General readers aren't going to know what a "Crazy Ivan launch" is. --ChetvornoTALK 15:15, 16 September 2015 (UTC)
Agreed, using jargon there was my bad. Maury Markowitz (talk) 14:22, 17 September 2015 (UTC)

JSTOR cleanup drive

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November 2015

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TRF and Neutrodyne

According to WP's Neutrodyne article, it is a special type of TRF rather than a separate type of radio receiver. Glrx (talk) 02:14, 16 December 2015 (UTC)

Absolutely. I just thought the sentence looked a little funny as it was. --ChetvornoTALK 04:55, 16 December 2015 (UTC)

Proposed new contributions

You have made a lot of useful contributions here even if you deleted some of mine (no offense taken, they were poorly introduced). In the non-radiative near-field section, I have planned to add soon some brief considerations concerning coupling coefficients and also to explain simply how resonance associated to large Q-factors improves the performances without modifying the link itself (the coupling coefficient depends only on geometric consideration or equivalently on self and mutal inductance or capacitance). I also think that the resonant induction could be introduced in a simpler manner (two distant coils in series with two capacitors), as it is used in most application (Witricity uses combined air transformers for impedance adaptation reasons nothing more). The same schematic is used in many recent papers for coupled capacitors (whatever the physical implementation). By the way the transverse capacitive configuration (not known as such) was introduced for power transfer by a New-Zealand guy a long time ago, but recent articles do not even mention him, can you help to restore his historical contribution. Finally they have been recently a few proposal based on radiative near-field techniques in the GHz frame (using for instance phase conjugation technique), they deserve according to me a section in the Wireless Power page. Besides, I am thinking on a Galinean Electromagnetism page that could be used for an elegant introduction of Quasi-Electrostatics and Quasi-Magnetostatics, your contributions will be appreciated.Henri BONDAR (talk)

Would it be okay if we moved this to the Talk:Wireless power page and I answered you there? That way we can keep the discussion together. Thanks. --ChetvornoTALK 14:36, 23 January 2016 (UTC)
Of course no problem. However, as I am quite new in the field :-)I don't know how to proceed for the transfer (copy/paste I assume).Henri BONDAR (talk)
Done ! Henri BONDAR (talk)

Project Diana

Hi Chet, My error in not signing in to edit the Project Diana page. The edits are factual.

The presence of the Ocean-Monmouth Amateur Radio Club on the Diana Site can be verified via both organizations websites [1] and [2]

The site is maintained by OMARC. OMARC was at that location before InfoAge was created under the supervision of the Department of Defense BRAC program. The arrangement was to mow lawns, paint buildings, pay for utilities, and be the custodians of the site.

You can verify location on Google, the IRS non-profit website, and the local phone directory.

Regards, Martin Flynn

N2mo (talk) 21:50, 14 September 2015 (UTC)

References

  1. ^ www.infoage.org
  2. ^ www.n2mo.org

Elements

...[4] yes, but distributed models are also represented and analyzed by elements. SpinningSpark 18:01, 4 June 2016 (UTC)

Okay, I agree. "Many" should be changed back to "all". Thanks. --ChetvornoTALK 06:15, 5 June 2016 (UTC)

Hi Chetvorno, I think it's good to add back "Society must have laws", but the first four references come from newspaper reporters and bloggers. For the purposes of a formal (or informal) application of logic, these sources are Wikipedia unreliable and should be removed. ~~ BlueMist (talk) 00:59, 16 June 2016 (UTC)

Hi. The references were not meant to establish that the given sentence is "valid", or that it is used in reliable sources, but just that it is widely used. Reductio ad absurdum is used in both scholarly debate and "informal" arguments such as blogs and newspaper letters, and whether the sentence has the form of a reductio is unrelated to whether it is a good argument. I added the references merely to give examples of the use of this particular reductio in public debate. Maybe I should have made that clear in the citations. --ChetvornoTALK 01:50, 16 June 2016 (UTC)
Reductio is only valid as a deductive argument! In the loose, real-world sense you are using it, it can be alleged to 'prove' any point of view whatsoever, including Machiavelli's or Stalin's societies. The reason is that the informal, empirical argument is always incomplete, or elliptical, and possibly, but not necessarily, unsound. In which case, anything goes.
However, I'm not arguing against this inclusion into the article, because this is indeed a common usage.
Only that according to WP:RS, the first 4 references are just not Wikipedia acceptable. ~~ BlueMist (talk) 02:53, 16 June 2016 (UTC)
Well, of course I agree that some reductios are more valid deductive arguments than others, and we want to use "valid" ones as examples. The problem in WP logic articles is that editors can argue endlessly about the validity of the content and meaning of an example like this, when the point of the example is to show the form of a reductio argument. You and I are agreed that this sentence is good enough to use as an example. The only reason I included the references was because in our recent Talk page argument with him, Rstrug demanded some; I was hoping to forestall another long argument with him. I agree the references are not very good; I'll remove the ones you object to. --ChetvornoTALK 16:48, 16 June 2016 (UTC)
Many thanks! I agree with the usage as stated. That one legit reference should be enough for support. ~~ BlueMist (talk) 17:55, 16 June 2016 (UTC)
I'll prove why reductio ad absurdum is dumb later on. You haven't refuted my argument, you've just ignored it. People adhere to the tenets of religion and none of them are laws. Rstrug (talk) 20:41, 16 June 2016 (UTC)
Oh well. So much for avoiding an argument. --ChetvornoTALK 23:00, 16 June 2016 (UTC)

Requested move

Hi, I followed up at WP:RMT. Any comments? — Andy W. (talk ·ctb) 00:41, 24 June 2016 (UTC)

Brought the request to RM here. Thanks. — Andy W. (talk ·ctb) 01:18, 24 June 2016 (UTC)
Looks fine to me, thanks. --ChetvornoTALK 01:33, 24 June 2016 (UTC)

Talk fix

Much better[5], I was getting lost there myself. Fountains of Bryn Mawr (talk) 17:24, 20 September 2016 (UTC)

Crank Slider Torque

Hi. Please check the torque equation for the [slider mechanism]. It is not correct as it now is.

The mechanical advantage of a crank, the ratio between the force on the connecting rod and the torque on the shaft, varies throughout the crank's cycle. The relationship between the two is approximately:

[1]

where is the torque and F is the force on the connecting rod.

Surgbc (talk) 11:24, 14 September 2016 (UTC)

Just a note

Thanks for all your edits. Glrx (talk) 19:23, 5 December 2016 (UTC)

Thanks. Your excellent in-depth research on the triode is fascinating, especially the Armstrong correspondence. It seems to me to make a pretty good case that the gas in the tube by itself isn't enough to make the Audion "not a triode". --ChetvornoTALK 08:36, 8 December 2016 (UTC)
BTW, the Audion article also desperately needs a rewrite. --ChetvornoTALK 08:36, 8 December 2016 (UTC)
The effort to discredit the audion as a gas tube seems misguided. De Forest was a crook and a cad and understood little about what he did; he was willing to lie and fabricate. Despite that, he was an experimenter and was looking to develop amplifiers and detectors, and he had some significant success. I don't see credible sources disputing a vacuum triode invention. I love Langmuir, but his efforts identified two competing theories and proved which one was correct. By 1915, Armstrong understood how vacuum tubes worked and how residual gas caused problems; at the same time, De Forest was confused about those issues. In a sense, Langmuir is more deserving of credit, but De Forest's invention is a vacuum triode even if the vacuum is imperfect.
There are some sources that make the gas distinction, but I don't see them as technically based. De Forest used lightbulb quality vacuum and that was good enough for some applications. De Forest's company did push imperfect vacuum audions; I had but lost a 1940s QST reference that described De Forest selling both hard and soft vacuum tubes. Another, earlier, reference by a De Forest engineer warned users not to operate their audions in the blue glow region because it hardened the vacuum and caused the tubes to stop working. There is material out there for a section about hard/soft vacuum.
A vacuum technology guy explained mean free path and ionization when I was curious about x-rays. He got me to consult a few textbooks, and that has taken me into Townsend avalanches, glow discharges, and arcs. Somewhere along the line I learned of the blue glow in an audion. A couple years ago, I talked with a Stanford PhD (ca 1950s) who claimed they ran working tube circuits with a blue glow, but it was so far in the past that he did not recall the details. He was in his 90s and has died.
Sigh. I used to bump into the late Jim Williams every so often, and sometimes Tom Lee would be around. Lee is fascinating; we had some wonderful discussions about digital filters, electromagnetic weapons, and bored soldiers swallowing the batteries in their IED shock sensors. If I bumped into Lee today, I'd quiz him about audions.
On a related note, I learned today that I B Wright (who commented about gas tubes at Talk:Audion) and Elektrik Fanne (who disputed capacitor purpose was break arc suppression at Talk:Induction coil and Talk:Ignition system) have been indefinitely blocked as sockpuppets. Glrx (talk) 21:44, 17 December 2016 (UTC)

PAVE PAWS

Hello, I am doing a small school project on PAVE PAWS. There is lots of confusing data online on where there are ACTIVE PAVE PAWS sites? I believe the only active site using the orginal PAVE PAWS site is 6SWS at Cape Cod. Is this correct? Thank you Terence starzl (talk) 21:59, 17 December 2016 (UTC)