User talk:GoldenMeadows
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[edit] Vacuum Tubes
Regarding your 'heater' failures as opposed to cathode failure: heaters are only used in indirectly heated valves (tubes). The heaters themselves although they did occasionally fail, it was comparitively rare for the heater of a valve to fail. The emissivity of the cathode dropped to a point were the valve would fail to amplify or oscillate long before the heater failed. Of course, in such a scenario the heater would never get to fail, as the valve would be replaced.
As for citation: I am an electronics engineer who has been in the business since the 1960's. My apprenticeship was based on valves, and I have been involved in building and maintaining many examples of valve equipment, some having output powers in the killowatt range and operating from many thousands of volts at many tens of amps. And some amplifying the tiniest of currents (< 10e-18 amps - that's pretty small). I therefore know a bit about the subject. In the 1980's, in conjunction with a colleage, we figured out a way of determining the grid crossover current of a valve. If you know what that is, you will know why it was previously impossible to measure. That colleague has now passed on, and AFAIAA, I am now the only person on the planet who knows how to determine the exact grid crossover current of a valve. There is a method of extrapolating it, but it only gives an approximation. Sadly the method has no commercial value as nobody uses valves any more. The only real application where this grid crossover current needs to be known has long ben taken over by MOS-FET devices.
Having said that, I have not encountered any valve where the heater has failed (other than due to being run from too high voltage). I am aware of plenty of filaments (directly heated) that have failed. I B Wright 21:01, 14 November 2006 (UTC)
[edit] More Vacuum Tubes
Thank you for you further comments. To answer some of your points.
The exact mechanism that shortened the life of valves was not fully understood at the time of the Second World War. Tommy Flowers (as you state) believed that the most harm was done during start up and shut down. Such was the lack of understanding that no one else believed him. Flowers nearly had it right: the most damage is done during start up. Whilst the cathode is warming up it was expected to start emitting electrons as soon as sufficient temperature was reached. This meant that the cathode was emitting at saturation until the temperature exceeded the point where the saturation current was greater than the required cathode current. This was a particular problem in Thyratrons where the the reverse flowing ion current would quickly strip the cathode under such conditions. Once Flowers demonstrated that he was correct in his belief, there followed greater understanding. Post war valve designs employed rectifier valves where the cathode was deliberately heated much more slowly than the rest of the valves. This minimised the wear (but didn't eliminate it completely) to the active valves at the expense of greater wear to the rectifier. However, the expense of replacement valves was considerably reduced especially as the rectifier was usually the cheapest valve.
I think Tony Sale's recollection of the powering of Colossus is faulty (remember he was not directly involved in the engineering side, being a codebreaker). Flowers, much like engineers today, didn't like to dirty their hands designing something as simple as a power supply. However, Flowers would have found a total lack of off the shelf power supplies for powering a 1500 valve project with capacity to spare for future expansion.
What he did was resort to the Westat power supplies that were actually designed for powering telephone exchanges (The UK used 50 volts then, rather than the more international standard of 48 volts in use today). They were rated at 50 volts at 20 Amps each. As you note, Flowers connected 5 of them in series to provide +200 and -150 HT rails for the valves. If you grab your calculator you will discover that each Westat unit is rated at 1kW each, the 5 of them accounting for the 5kW. But this was only the HT supply. The Westat units did not power the heaters of the valves (they wouldn't have provided enough power anyway). These were separately fed from a transformer. What I don't know is whether the heaters were parallel connected (as is the norm for 6.3 volt valves) or series parallel. My information on Colosus says that Mullard EF37s were used (which happens to be a close equivalent of the VR56). I don't have a data sheet for the VR56 (strangely), but the EF37's heater is rated at 200 mA (which may be why this particular valve was chosen). The thyratron valves would be about 800 to 1000 mA each (and there were 508 of those required to emulate the Lorenz rotors). The power required to heat those and 2000 odd EF37s as ever with valve equipment dwarfed the HT power requirements. The rebuild has had to sacrifice authenticity for availability and has been made using the post war improved EF37A (lower microphony and lower heater induced hum).
I was not refering to directly heated valves when I said that I had never encountered an open circuit heater. I have encountered a few open circuit filaments in directly heated valves. I didn't say it didn't happen, just that I hadn't encountered them - not even when I serviced valve colour televisions, and I don't recall my colleages encountering one either (the frantic trial replacement of each valve in turn would have been a dead give away), so I do not accept that it was a common failure mode.
I am not convinced that thermistors were incorporated in the heater chain of AC/DC televisions for the purpose of slowing down valve failure. AC/DC radios got along quite happily without them. I believe that the thermistor was purely to limit the switch on surge (though the lowering of the stress to the heaters was a convenient side effect). The principle risk to the heater wasn't the bit of the heater that was actually inside the cathode tube, but the few milimetres that led from the cathode to the connection point. On applying power, this short length, in many valves, lit up like a light bulb and then dimed down as the heater reistance rose and the current fell. Parallel connected valves (E series) did this as well and they had no thermistor either.
Heater failure due to burn out is already mentioned in the Vacuum Tube article. It does not belong in the Colossus part of the article because that is not the failure mode that Flowers was trying to eliminate. The most common cause of a 'burnt out' valve as people incorrectly describe it, is emission failure of the cathode and it was this that Flowers was addressing.
I should perhaps end by observing that Mazda's AC/ series valves produced in the 1930's never failed. I never encountered a failed one (low emission or open circuit heater). Like many a service shop, we bought a full set of spares and never used a single one.
I B Wright 12:36, 18 November 2006 (UTC)
- I just had a look at te VR56 page that you linked to and one or two other pages that reference this valve. The shape of the VR56 doesn't quite match the shape of the valves that can be seen in some of the very rare wartime photographs. However it is more than likely that in order not to attract undue attention to the size of the project (25,000 valves is bound to get noticed), that valves may have been multi sourced. I think the VR56 may be a Canadian device (Do you know where they came from?). I have not been able to locate a VR56 data sheet.
- I was curious about the CV1056 on which someone has helpfully written 'EF36' in pencil. A quick trawl through my data sheets reveals that the EF36 was a forerunner of the EF37 (later improved to become the EF37A). The EF37A data sheet is actually headed EF36 and EF37A. the only qualification is the anti microphnic construction of the later valve.
- I B Wright 23:12, 19 November 2006 (UTC)
[edit] Religous perspectives on dinosaurs (Rpod)
Thats a good point you raise there about species dying and Garden of Eden. Do you have a source for it? SmithBlue 02:18, 17 January 2007 (UTC) Hi -Orangemarlin is posting that "you have called us stupid twice". I can't find what he is refering to. Please point it out to me if you know. Your rewrite looks very interesting. One "bullet proof" way of including it is to put it forward as "Historical Christian Religous perspective on dinosaurs" - properly cited its then beyond dispute (by reasonable editors and we can find those if we have to.) I've never met fundamentalists before (scientific ones that is) - its not a pleasant experience. SmithBlue 00:10, 19 January 2007 (UTC)
- Re-reading posts on the discusion page I begin to think of the story about BillyGoat Gruff and certain beings that lived under a bridge. The lack of contribution to article of material supporting claimed position, the slow revert war over "kinds", the stated belief that "there are no religous perspectives on dinosaurs", the "call us stupid" claim,
the avoidance of:
- questions asked about the editors own position,
- historical Rpods,
- nonUS and nonWest European Christianity Rpods,
- Rpod of fundamentalist Muslims and Jews and Hindus,
all give weight to your question of "serious contributor?". I wont be paying much further attention to editor posts unless material is contributed. SmithBlue 02:49, 19 January 2007 (UTC)
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- Goat-Gruff Theory didnt stand up - quick read of editors's talk pages shows apparent genuine editors. They been comming for a while - appear to dislike creationists. However editor is aware of many issues that the editor avoids at Rpod(as above). SmithBlue 03:14, 19 January 2007 (UTC)
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- Did you accuse me of being a troll? Wow. After a couple of thousand edits, I don't think I'm that, but if you don't like my opinion, I'm not going to lose much sleep. As for your other statements--wow, nice POV. Do you not think that there are a few hundred editors on here that might find what you just wrote to be, well, somewhat antagonistic?. And just because you claim that you are somehow superior to me and others with regards to this subject, does not in fact mean that you actually are. I do not like Creationism--I have no opinion of creationists (as opposed to what you wrote above), unless they throw their unverified, faith-based, illogical, and unscientific opinions into a public school system. I draw the line there. Remember, I don't care about this article, even in the slightest. That is, I'm not going to write one thing, because I know that dinosaurs existed between 230 and 65 million years ago, and they do not current exist, save for the somewhat controversial argument about birds, which is neither here nor there. Therefore, if you (meaning Creationists) want this article, go for it. But if you're going to title it, "Religious perspectives on Dinosaurs," then it has got to follow WP:NPOV. If you want to re-title it "Creationist perspectives on dinosaurs", go for it. Of course, the first sentence will stand. You know, that Dinosaurs arose in the Cretaceous, 230 million years ago, etc. etc. I do not want to engage in a fight with you. But honestly, re-read what you wrote. If you don't think it's condescending, and, in essence, calling us stupid, then you and I have a whole different interpretation on lots of things, not the least of which is the age of the earth. If you think that your sentences, including "I don't think you have grasped the issue about original sin and dinosaurs," aren't insulting, then you must not grasp how to be polite. I grasp the issue, I just think you're wrong. So, my interpretation of your sentence is, "you don't agree with me, so you're daft." I would prefer you to be civil to me and others who may not subscribe your POV. I think I'm right on the lack of NPOV of this article, but if you don't agree, then put it up there for consensus, don't hide on your talk page and insult me. If the editors all agree that your POV is actually NPOV, so be it. But I will stand up to your edits until that time, because you are trying to put your POV. Which isn't right. Not your POV, that is, just pushing it. Orangemarlin 08:47, 19 January 2007 (UTC)
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- Orangemarlin you appear to be mixing me (GoldenMeadows) with Smithblue. This is my talk page if wish to debate with anyone else please use the relevant page. Amongst all of the above you do mention a point that does relate to a contribution I made, not Smithblue, i.e original sin. I note your liberal use of mocking language with respect to other contributions, "actually can't believe I wasted a good 30 seconds reading this drivel." and your very quick assumption that other people are biassed etc., with your use of alarmist headers. At the same time you appear to be extremely sensitive to any perceived criticism of yourself. I repeat that I never thought you stupid never mind said your were stupid - please do not project on to me the products of your own imagination. There was, and is, no malice in my opinion that you had not grasped the significance of the age of dinosaurs and original sin, it seemed to be a simple and honest observation based on erroneous assertions you made. GoldenMeadows 21:16, 19 January 2007 (UTC)
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- It was drivel. And yes I mock those who waste my time, especially, as I believe you're referencing, when someone posts that Dinosaurs lived at the same time as man. I was much nicer than most of the other responses. It appears you've been posting for a couple months, and just very recently in a creationist area. I don't know if you're going to be one of the calm rational creationists or, well, not. For the past two weeks there was a definite troll (who happened to be a creationist) on one of the articles causing enough problems. So, I'd have to say, even the administrators have become fairly undiplomatic. I guess we should assume good faith and that you don't come in to cause problems, and you haven't. So accept my apologies. But what you have written does appear to be insulting to me. And I do not have thin skin. Remember, I'm an MD, and I happen to walk on water. :) Orangemarlin 01:12, 20 January 2007 (UTC)
- Thanks for your comments. I can understand how debates with people who have a fundamentalist disposition can be very frustrating and in some ways provoke a similar response. I assure I have no axe to grind on this subject. There may be ideas put forward through certain forms of creationism that I simply do not believe because it contradicts the available scientific evidence and I may find certain claims put forward as science exaggerated. It would not stop me reporting those beliefs if they represented a significant number of people or if they had a significant impact in a given society even though they were only held by a minority, albeit influential, section of the community. For example if a country has only small minority of people who believe in a literal six days account of creation yet they have an disproportionate influence on that society, for example in education, politics or the media, then I would cite the best available work(s) I know that support their idea but I would also put in the best arguments against them in a concise summary of the issue with links wherever possible to other articles that examine particular issues in more depth. I approach these kind of articles by imagining that I am an open minded reader who knows little about the subject but would like to see what the main issues are without anybody censoring or filtering out material they personally do not believe in. This imaginary reader likes to form his own opinions based on the best available information with a preference for top down structure in the article, i.e. general outlines of the issue followed by a more detailed exposition. I hope this helps you understand my outlook. Finally I am sorry for offending you, it certainly was not intended, and if our paths ever cross on the sea be sure to say hello! GoldenMeadows 21:54, 20 January 2007 (UTC)
- It was drivel. And yes I mock those who waste my time, especially, as I believe you're referencing, when someone posts that Dinosaurs lived at the same time as man. I was much nicer than most of the other responses. It appears you've been posting for a couple months, and just very recently in a creationist area. I don't know if you're going to be one of the calm rational creationists or, well, not. For the past two weeks there was a definite troll (who happened to be a creationist) on one of the articles causing enough problems. So, I'd have to say, even the administrators have become fairly undiplomatic. I guess we should assume good faith and that you don't come in to cause problems, and you haven't. So accept my apologies. But what you have written does appear to be insulting to me. And I do not have thin skin. Remember, I'm an MD, and I happen to walk on water. :) Orangemarlin 01:12, 20 January 2007 (UTC)
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- I think we all want to see a clear article written describing the views, either of a broad swath of religions, or from Christian biblical literalists. I think it is fascinating, but I just would rather that it not be presented as the only view, or as one that is well supported by science, or not disputed by scientists, and other religious views.--Filll 22:09, 20 January 2007 (UTC)
- Like you I also would like to know what other religions think. I suspect that people who could make real contribution in these areas may have been put off in the past if there have been ongoing arguments with extremists - they don't want or care for the hassle. GoldenMeadows 22:47, 20 January 2007 (UTC)
- I think what we should try to do, all of us from all sides, is to just put as much material as we can into the article, without reverting it or arguing much at all, even if we disagree. Then we can try to edit it to something comprehensible and hopefully balanced.--Filll 23:34, 20 January 2007 (UTC)
- Agreed.
- Like you I also would like to know what other religions think. I suspect that people who could make real contribution in these areas may have been put off in the past if there have been ongoing arguments with extremists - they don't want or care for the hassle. GoldenMeadows 22:47, 20 January 2007 (UTC)
This is hilarious. I have not written much yet on your Rpod because I have actually been doing real work on real articles. I agree completely with OM. This article does not give the religious perspective, or even the Christian perspective or even the fundamentalist perspective or evangelical perspective or creationist perspective or even the young earth creationist perspective but one variety of young earth creationist and biblical literalist perspective that is popular in one country. Period. That is it. So either broaden it, or be honest enough to write it with the appropriate title and qualifiers. Now I think if you broadened it to give a variety of religious perspectives it could be interesting. This would also be a lot of work, so you might not want to do that. You could also be honest about what it is about and write it accordingly, but I think that might hurt your ego to face up in a NPOV way to the fact that this is a very very very very narrow little view of dinosaurs. It might also be funny as heck if you wrote it that way (it is funny now). But to survive it needs to be either honest and NPOV, or broad and NPOV. I guess you are asking me here to make Rpod an AfD. You want to dance? Baby, let's dance. Let's really see what the "consensus" is about Rpod. What do you think the community will say. Want to find out? Or do you want to settle this quietly and like real "Assume good faith" honest editors striving to write NPOV articles for a worldwide secular encyclopedia.--Filll 12:35, 19 January 2007 (UTC)
- Could you please use the discussion page of the article in question for debating points with other contributors. Your cooperation would be appreciated. GoldenMeadows 21:21, 19 January 2007 (UTC)
- What is an Rpod? I thought he was writing about another user. LOL. Is it another method by which certain people use the Wiki rules to cause a war rather than discuss it to get consensus? Ridiculous. Orangemarlin 17:09, 19 January 2007 (UTC)
[edit] [WP:Dinosaurs are sexy]
hi GoldenMeadows, you are contributing good material for the article. If you werent I would be on the definately no side of name change. As you might have realised I really like the present title. But unfortunately this is meant to be a serious encyclopedia not a play area. So I am not going to try and stop a name change. Nor, unless you appear to be in great need of help getting it happening, will I assist. Or even better someone else might come up with solid reasons for keeping the present title! I know; sometimes I'm not a good editor. SmithBlue 03:05, 2 February 2007 (UTC)
[edit] Religious perspectives on dinosaurs
Great job and ot bad for an Engineer!! :) Your edits are NPOV and well written. You deserve kudos on a very sensitive subject. Orangemarlin 17:28, 6 February 2007 (UTC)
- Thanks for your kind and encouraging words. GoldenMeadows 18:05, 6 February 2007 (UTC)