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javielectronicamateos@gmail.com: Sep 14 07:53AM -0700 El jueves, 21 de julio de 2016, 20:31:31 (UTC+2), Gareth Magennis escribió: > at high HT.   > Cheers,   > Gareth.   Hola, el condensador es de 2,2pf 2kv y poner un fusible de 3,15a y a funcionar.

Ralph Mowery <rmowery28146@earthlink.net>: Sep 13 12:57PM -0400 I bought a Hantek 200 MHz digital scope and ahve been learnign to use the a digital vers an analog.   One problem I seem to have is trying to display an AM signal and getting it to look like my Analog scope when setting it for 100 % modulation. Out of a signal generator into my analog it looks like it should, but I havenot been able to get the digital to show anywhere close to what it should.   Does anyone have any ideas on what I may be missing or are the digital scopes not set up to do that.

jeanyves <jeanyves@nowhere.com>: Sep 13 09:13PM +0200 On 2016-09-13 16:57:17 +0000, Ralph Mowery said:   > should.   > Does anyone have any ideas on what I may be missing or are the digital > scopes not set up to do that.   it depends on the frequency of the signal you want to display but consider that any signal higher than 1/10th of the bandwith (so 20MHz) won't be displayed properly on a digital scope, as an analog scope will display ok to the full bandwith. --   Jean-Yves.

JW <none@dev.null>: Sep 13 04:12PM -0400 On Tue, 13 Sep 2016 21:13:13 +0200 jeanyves <jeanyves@nowhere.com> wrote >but consider that any signal higher than 1/10th of the bandwith (so 20MHz) >won't be displayed properly on a digital scope, as an analog scope will >display ok to the full bandwith.   Got a cite for that?

mike <ham789@netzero.net>: Sep 13 02:35PM -0700 On 9/13/2016 1:12 PM, JW wrote: >> won't be displayed properly on a digital scope, as an analog scope will >> display ok to the full bandwith.   > Got a cite for that?   interesting how people won't believe what they're told, but will believe someone they reference.   Set the sweep rate to whatever you want to see. Reduce the source frequency until the display looks like you want. That's your answer. Nothing anybody says will change the result. Understanding the math won't change the display. Digital scopes suck at some things.

Ralph Mowery <rmowery28146@earthlink.net>: Sep 13 06:32PM -0400 In article <nr9rhs$j98$1@dont-email.me>, ham789@netzero.net says... > That's your answer. Nothing anybody says will change the result. > Understanding the math won't change the display. > Digital scopes suck at some things.     Looks like a digital scope will not display an AM signal like the analog one will. I finally found an explination on the internet. They just can not take enough samples fast enough. I even tried going to 1 MHz carrier and 500 Hz for the modulation tone and the display was still messed up. I would have thought a scope rated for 200 MHz would work at 10 MHz even if from China. It does do as good or beter than the 200 MHz band width while displaying a sine wave.   I think the artical was written around 1998 and would have thought the scopes would be beter by now, but just can't beat the math.   http://www.rocketroberts.com/techart/sigproc.htm   While the scope I bought was one of the China versions, it had good reviews. I though it might be the China copy,but doubt any scope would be beter , atleast in the under $ 50,000 catagory.

Phil Allison <pallison49@gmail.com>: Sep 13 04:41PM -0700 jeanyves wrote:   > but consider that any signal higher than 1/10th of the bandwith (so 20MHz) > won't be displayed properly on a digital scope, as an analog scope will > display ok to the full bandwith.   ** Complete nonsense.   The effective sampling rate sets the upper frequency limit for DSOs - which for the OP's scope is 1GSa/s. 200MHz is the analogue bandwidth of the input attenuation & buffer circuitry.   The problem with DSOs is that the sampling rate varies with sweep speed and this affects their ability to show high frequency detail at low speeds and also results in aliasing.   Analogue scopes have fixed bandwidth at all sweep speeds and can be trusted to show mixed frequency signals correctly.   .... Phil

dplatt@coop.radagast.org (Dave Platt): Sep 13 05:58PM -0700 In article <MPG.32424894fd79e297989749@news.east.earthlink.net>,   >Looks like a digital scope will not display an AM signal like the analog >one will. I finally found an explination on the internet. They just >can not take enough samples fast enough.   It really depends a lot on the specifics of the digital scope.   >and the display was still messed up. I would have thought a scope rated >for 200 MHz would work at 10 MHz even if from China. It does do as good >or beter than the 200 MHz band width while displaying a sine wave.   It's important not to conflate the scope's analog bandwidth, with its sampling rate... or to confuse a "real-time" sampling rate with an "equivalent time" sampling rate!   Some of the less-expensive digital scopes may quote a high analog bandwidth, but sample at a fairly poor rate... e.g. a 100 MHz scope which samples at only 150 or 200 megasamples/second. A scope of this sort can only let you look at fast waveforms well, using "equivalent time" sampling, and this requires a "repetitive" waveform that doesn't vary significantly between one scan-sweep and the next.   On the other hand, a "100 MHz" scope with a 2-gigasample rate can do a very decent job on fast, nonrepetitive (i.e. modulated) signals. It'll also cost more, due to the need for faster ADCs and memory.   Other tidbits:   There are a number of things that can influence how well the scope can show you what you want to see.   If your scope is simply displaying the individual samples, and drawing straight lines between the points, then you probably need a sampling rate of at least 20x the carrier frequency (or more) in order to avoid having the display confused by the "chopping off" of the tops of the waveforms when the sampling time doesn't happen to fall right on the peak of the waveform. 50x is even better.   Some digital scopes have the ability to interpolate... they'll do some sort of polynomial or sin(x)/x curve fitting or filtering, and will show you a display of what they *think* the actual waveform would have looked like on a continuous (i.e. analog) display.   You can also run into problems where a scope deliberately reduces its sampling rate, because it's been configured to capture a large amount of the waveform "before" and "after" the trigger point, and let you scroll through it. The scope has only so much memory available, and if you tell it you want to capture a long interval of the signal, it has to reduce the number of points it captures per (micro or milli)second in order to fit the data in memory. This can drop the *actual* sampling rate well below the Nyquist point, and results in all sorts of confusing-looking aliasing of the signal on the display. It might be worth turning down your scope's "capture width" to be no more than can fit on the screen... and checking the display to see if you can confirm that the *actual* data-capture rate is high enough.   Some digital scopes drop their sampling rate in half if you use both channels. The popular Rigol DS1052E/1102E can sample at 1 gigasample/second on one channel, but only 500 gigasamples/second if both inputs are active. If you don't need the second channel, turn it off!   And, part of the problem is sometimes that the scope's display just doesn't have enough horizontal resolution. If it only has, say, 640 pixels in each horizontal line (VGA resolution), or worse yet only half that many, you're not going to see a terribly smooth waveform no matter how fast you sample it. In addition, most inexpensive digital scopes are sorta "colored monochrome" - they either light up a pixel in a color, or don't, but have little or no ability to vary the *brightness* of a pixel.   You may get better results if you use the scope to sample, then upload the waveform data to a PC via USB or GPIB and view it on a higher-resolution display (and/or with a plotting program that can implement an anti-aliased display with at least 8 bits of intensity).   So, there are often things you can do to make a digital scope more usable for signals like this... but I agree with you that an analog scope is often a much more satisfying solution. I have both types, and haul out the Tek 2232 (or wheel out the 7904) as often as I do any of the digital scopes.

Ralph Mowery <rmowery28146@earthlink.net>: Sep 13 11:29PM -0400 In article <4ujmad-f6h.ln1@coop.radagast.org>, dplatt@coop.radagast.org says... > scope is often a much more satisfying solution. I have both types, > and haul out the Tek 2232 (or wheel out the 7904) as often as I do any > of the digital scopes.     If I did not post it, the scope is a Hantek dso5202p which is a 200 MHz scope and a 1 GB sample rate if only one Chanel is use. It does the sin (x)/x thing to smooth the curve between points. The scope may blow up but for the money it seems to be a very nice hobby scope. Bought it new for only $ 299 from a company in the US. It does have a 3 year warranty I feel safe with it. I am retired now and just thought it would be nice to play with a digital scope. I am now finding out some of the limitations of them. Glad I still have an old Techtronics 465B analog. Seems that going to the X-Y display is not very good either if I want to compare 2 signals that are very close in frequency. Never could get the circle to show up and rotate slowly. It will show up if I hook both probes up to the same signal and an elips due the the slight delay between the signal.

Phil Allison <pallison49@gmail.com>: Sep 13 09:55PM -0700 Ralph Mowery wrote: > the X-Y display is not very good either if I want to compare 2 signals > that are very close in frequency. Never could get the circle to show up > and rotate slowly.   ** Nothing approaches using an analogue scope with Lissajous figures - and you can make very complicated and rather pretty ones too with the help of some phase shift networks.   Back in the 1980s I needed to check the AC supply frequency to see how it varied and not having a period counter I used my scope in X-Y mode. I also had a valve audio generator with very fine frequency adjustment ( due to the use of a 30:1 reduction drive on a large tuning gang ) and a regular frequency counter.   Producing a nice circle was dead easy but only resulted in an +/- 1 Hz precision due to uncertainty with the last digit on the counter. So I set the generator to 500Hz and steadied the pattern, giving me 0.1Hz resolution on the counter. Next I tried 5kHz and that gave me 0.01Hz accuracy - going any higher proved impractical.       .... Phil

jurb6006@gmail.com: Sep 14 03:21AM -0700 >"Producing a nice circle was dead easy but only resulted in an +/- 1 >Hz precision due to uncertainty with the last digit on the counter. >So I set the generator to 500Hz and steadied the pattern, giving me >0.1Hz resolution on the counter. Next I tried 5kHz and that gave me >0.01Hz accuracy - going any higher proved impractical. "   Interesting usage. Let me guess, this was because back then most clocks either had a synchronous motor and even most digital ones used the power line frequency as a clock.   That is the only reason I can think of, if it was something else do enlighten me. I know there is alot of weird shit out there. We had TVs build with an SCR regulator which of course also rectified, and they weren't picky so much about frequecy, even triac light dimmers aren't all that picky. Of course they might be a little different for 50Hz but then it is probably a different set of components anyway for the 240 volt mains in such countries. I do know that in the old days power companies had to adjust because under heavy load the generators would slow a bit, so they sped them up a bit to compensate during low load periods, pretty much so the clocks kept time.   I was in an interesting position at my shop there was a ground fault in the heating system but I was getting 3,500 square feet for like $350 a month which is dirt cheap even then, and that included heat. My shop had CEI which is on the TVA grid and the factory where the boiler was was on CPP which is on the PASNY grid and they were not synched. Sometimes I would pick up like 330 volts. I know it was dangerous but we were nuts back then and just put the benches where you wouldn't get shocked. You would have to barefoot and spill something. The reason was obvious, because the load patterns were different. The TVA is south and PASMY is north. This is one of the few cities where people in some areas actually have a choice. Generally the require that choice be made on a buildingwide basis and I guess I see why, but somehow they had both in that building. (in the back they had a plastic injection molding plant making parts for Mr. Coffee, of course that kind of industry is gone now)   Anyway, I never bothered to put a scope on it but I would guess that for 60 Hz it never varied more than +/- 0.5 Hz. The only things that would require that accuracy would be clocks. Well maybe high fidelity turntables. Back in them days even my favorites, Duals used a synchronous motor and a tapered motor shaft for speeed control. However, the speed indicator strobe light ran off the power line so if it was off, your speed was off. (my ?Uncle used to use a stopwatch and put a piece of masking tape on the platter and sit there and count the revolutions, some people are picky about such things ad also made his olady strain the gravy)

jurb6006@gmail.com: Sep 14 03:37AM -0700 >"Glad I still have an old Techtronics 465B analog. "   Despite whatever gripes you might have about that scope, it is one of the prime old Teks to have. We have one and played with it and it has the ability to display both A and B sweep simultaneously. Very few scopes have that ability as far as I know. Now this one stopped triggering B sweep, I suspect Q4565 but have had other things on my mind. Plus the way they activate it by driving the emitter I don't want to throw just any transistor in there, except maybe for test. The pulse is there on the emitter, the bias is on the base, but the collector is a flatline, at a higher voltage of course. I suspect I am going to need a really fast transistor for that power range which isn't that high, but it has to ahndle a pretty high base to emitter current, so just a higher hfe, or HFE isn't going to cut it. they generally don't want high base currents, that is the whole idea of higher gain ! I would consider a high speed power switching transistor but it is socketed and I do not want to maul it. And I really don't want to modify it.   I'd like to keep it as stock as possible, it is in decent cosmetic condition except for those leggy thing at the back so it stands up on the floor, apparently they saw some use. But all the knobs and pots and switches are fine and the trace it sharp with no screen burn.   So it is on my bench all apart, but it is not holding up any other jobs, there is an old Pioneer receiver I need to order a bunch of transistors for but there is not rush on that. Other than that I just go to work, fukit. they are slowing down so maybe I'll get back on it. I can probably scare up a transistor for it around here once I do some math. Maybe. I just hate ordering things that only cost like thirty cents.

jurb6006@gmail.com: Sep 14 03:53AM -0700 >" I have both types, >and haul out the Tek 2232 (or wheel out the 7904) as often as I do >any of the digital scopes. "   Yeah, "wheel out", you got that right. We got a 7834 and I think they weigh about the same. If you don't have a scopemobile or something similar, get rid of it. Or hire some kid to move stuff around.   Actually I got an old 561A in the garage on top of a stand for a little buzzbox fluxcore welder. I need to fix that. It works but has a HV arc and if not plugged into a grounded outlet shocks you. Cool little toy for the Man cave out there. Yup, we got a propane heater for the winter and a stereo with a CD player. Actualy and a mixing board and microphone as well. But none of us have gotten drunk enough to really enjoy it lately...   We also have a bunch of 7000 series plugins, some quite coveted, which might go on the block soon if anyone is interested. We don't have any spectrum analyser or that type of stuff, but there is a 1 GHz plugin that exceeds the limits of the 7834. If you want it make offer, and we do barter. That one is strictly 50 ohm input. There is also a differential amp that can take some serious offset and has an astronomical CNRR. Got a few of the good horizontal plugins as well but I think a couple of them don't work right. But there are like 13 of them in the collection and the scope only takes four. So (LOL) I figure we need no more than eight.   Would definitely trade a bunch of them and other stuff for the spectrum analyser. IF you, or anyone is interested just post and I'll make a list of what they are and their condition. I think there are a couple that work fine and have a broken knob or something, but a knob can usually be taken off a cheaper one.   But you may consider me a Tek CRO afficianado. I will not say fan because that word is based on the word phanatic, I am not a fan of anything. It's just I have never seen scopes that work as well as those old Teks.

jurb6006@gmail.com: Sep 14 03:55AM -0700 >"If your scope is simply displaying the individual samples, and >drawing straight lines between the points, then you probably need a >sampling rate of at least 20x the carrier frequency (or more) in >order to avoid having the display confused by the "chopping off" of >the tops of the waveforms when the sampling time doesn't happen to >fall right on the peak of the waveform. 50x is even better. "   Sure, but where is the button for that ?

JW <none@dev.null>: Sep 14 07:11AM -0400 On Tue, 13 Sep 2016 14:35:54 -0700 mike <ham789@netzero.net> wrote in   >> Got a cite for that?   >interesting how people won't believe what they're told, but will believe >someone they reference.   Sure, because that was a ridiculous statement. I'd like to see cite from a reputable source that would back that up.   Can't find one, can you? Maybe jeanyves can?   Bet not.   >That's your answer. Nothing anybody says will change the result. >Understanding the math won't change the display. >Digital scopes suck at some things.   I wouldn't use a Chinese scope for anything. They just can't be trusted.

ggherold@gmail.com: Sep 14 07:14AM -0700 On Tuesday, September 13, 2016 at 12:57:10 PM UTC-4, Ralph Mowery wrote: > should.   > Does anyone have any ideas on what I may be missing or are the digital > scopes not set up to do that.   Try a single sweep on the DSO that may look better. (or not.)   George H.

Horace Algier <horatio@horatio.net>: Sep 14 04:40AM On Wed, 14 Sep 2016 00:24:59 -0000 (UTC), William Unruh wrote:     > You cannot. There is no necessary relationship between IP addresses and > location. Now often there is some rough correlation, but that is all you > can do.   I realize you're trying to help, so I will just try to be gentle at the same time I'm trying to be blunt (you can do the same with me).   Nobody said anything about IP addresses. And the *location* is inside of Google's database.   What I'm trying to understand is how the system works. And then I'm trying to see if there is a *vulnerability* in the system.   I'm not a hacker (as a hacker would have far more technical acumen and a hacker wouldn't be asking about a vulnerability on the net like this).   What I see is a *vulnerability* but you're *never* gonna see that vulnerability if you keep talking about IP addresses!   >> other from anywhere in the world: >> https://developers.google.com/maps/documentation/geolocation/intro   > Nope.   I realize you're trying to help, but just saying "Nope" wastes *everyone's* time, including yours and mine - but mostly other people have to read me responding to you, which, if all you say is "Nope" means you don't have a clue what you're talking about.   It's a *fact* that you can query Google's database to find the *location* of a BSSID. Google implemented a (IMHO weak) "security" system by requiring *two* BSSIDs.   It's this weak security that I'm searching for the vulnerability of.   It's a *fact* that you only need three things to get a GPS location out of the Google database: 1. BSSID 1 2. BSSID 2 (added as a weak security feature!) 3. Signal Strength   Do you dispute *that* fact?   >> 2. MAC ADDRESS #2 >> 3. A fabricated signal-strength value   > Except for fun, I would not rely on it.   That's not at all the point! I am probing a perceived privacy vulnerability in the Google system. I am doing this not to take advantage of that perceived vulnerability, but to better *understand* that privacy vulnerability.   Specifically, with the facts known, "if" your cellphone does broadcast an SSID, then your cellphone *can* be tracked.   Do you dispute that statement (which I have backed up in gory detail already)?   Why or why not? > As a trivial example, lets say I run a VPN from Vancouver to Italy.   *[Where is Jeff LIebermann when we need him?]*     What on earth does this question have to do with IP addresses?   I realize you're trying to help - but what you're doing is *jumping* to conclusions that *nobody* else is talking about.   VPN has *nothing* whatsoever to do with this problem. The entire Internet has (almost) nothing whatsoever to do with this problem.   The *only* way the Internet is even involved is that your neighbor's cellphone is *sending* your SSID & MAC & GPS location & Signal Strength (etc) of your router *over* the Internet to Google.   So the IP address (and VPN) is completely irrelevant to this question.   > My > IP will probably be an Italian one as far as the world is concerned. My > computer however is in Vancouver.   This question has absolutely nothing to do with IP addresses and VPNs. Where did you get the idea that the question had *anything* to do with the Internet? I'm sorry if I'm being too blunt, but I'm focused on getting the answer to a *simple* question.   Q: When does an Android cellphone broadcast an SSID?   NOTE: The SSID has nothing to do with the question but people get all hung up if I ask the question this way:   Q: When does an Android cellphone broadcast a BSSID?

Horace Algier <horatio@horatio.net>: Sep 14 04:41AM On Wed, 14 Sep 2016 00:27:22 -0000 (UTC), William Unruh wrote:     > Those have nothing to do with the MAC addresses. And the Mac address of > a device ( a wireless card-- that is what a MAC address is the address > of) can be changed at will   Thank you for trying to help answer the question, as I realize answering such a deeply technical question involves risk - and we need to communicate so that we don't waste time on completely meaningless tangents.   First off we have to agree on some terms, and which are meaningful for the purpose of *this* thread:   - SSID: This is *not* very meaningful for the purpose of this thread! The SSID is only meaningful in that you can "do things" with your SSID which tell Google to do *other things*, e.g., you can append "_nomac" to the end of the SSID and Google promises to *drop* your information from its databases. But since SSIDs are not generally unique, the SSID is not the focus of *this* discussion.   - BSSID: This *is* the focus of this discussion, where each router has *multiple* BSSIDs (aka MAC addresses) and where the focus of this discussion is *only* on the one unique MAC address that is transmitted in companion with the SSID of an access point!   It's critical that you understand that your statement is patently incorrect that the router MAC addresses that *Google* is collecting using your neighbor's Android device are easily cloned.   The MAC addresses that Google is collecting using your neighbor's poorly configured Android cellphone are *not* easily changed (you have one per each radio, e.g., 2.4GHz and 5GHz, for example).   These radio access point MAC addresses are NOT easily cloned! This has been covered in this newsgroup in detail in the past.   However, even if the router's MAC address could be cloned (it can't, at least not without desoldering and other heroic actions), it *still* would be collected by your neighbor's poorly configured Android device.   So, it doesn't matter that you can't clone the MAC address that Google is collecting by using your neighbor's Android device to automatically send that information to Google periodically during the day.   The fact is that all poorly configured Android devices are automatically sending Google throughout the day *your* MAC address of your router.   NOTE: While I'm completely aware that turning off SSID broadcast is possible (and that it's not useful for security), we are assuming for this purpose that the SSID is broadcast by the router.   >> Does a mobile device broadcast its MAC address when acting as a hotspot, >> for example?   > No.   I realize you are trying to help - but I must be blunt, since this *is* the critical question.   Since this *is* the critical question, a simple "No" is not enough, especially since your previous statements in this post show that you misunderstood completely the question and the situation.   I'm sorry if that sounds mean, but, a simple "No" is not believable under those two circumstances.   The correct answer might still be "No", but you don't understand the question yet, nor the technical situation, so a "No" all by itself doesn't help.   My key question is *when* does an Android cellphone broadcast the MAC but most people get all hung up about MAC addresses - so I'll dumb down the question to ask "When does an Android cellphone broadcast an SSID?".   Q: Under what conditions does an Android cellphone broadcast an SSID? NOTE: I don't care about the SSID - I care about the MAC - but people get hung up about MAC addresses so I'll ask it in the simpler form.

Andy Burns <usenet@andyburns.uk>: Sep 14 07:35AM +0100 Horace Algier wrote:   > I'll dumb down the question   Doesn't matter if the hat says "Alice J", "Aardvarks" or "Horace", people don't want to go over the same ground again ...

Frank Slootweg <this@ddress.is.invalid>: Sep 14 07:54AM Horace Algier <horatio@horatio.net>... oops I mean "Aardvarks"... oops I mean "Paul M. Cook"... oops I mean "VPN User"... oops I mean "Joe Clock"... oops I mean "Marob Katon" ... oops I mean "Chris Rangoon"... wrote:   > Q: Under what conditions does an Android cellphone broadcast an SSID? > NOTE: I don't care about the SSID - I care about the MAC - but people get > hung up about MAC addresses so I'll ask it in the simpler form.   You don't ask a dumbed down question, but a dumb question and your 'question' isn't a question, but a false statement.   HTH.

jurb6006@gmail.com: Sep 13 04:48PM -0700 Well for one there are thermoplastics and thermosets. A thermoset will not remelt once it is hardened. Silicone seems to have alot of the properties of a thermoset.   Some things just do not melt they burn. Like you can't melt a tree for example. However the flash point of most sinlicones seem to be quite high.   On old Zenith TVs that had triplers, for example the 25GC45Z chassis (I am sure you've never seen one but I gave the chassis number in case you care to look it up). They used this black silicone on the input wire which carried about 9 KV AC, 70 KJz half sine pumped at 15.734 KHz and had some current behind it and as such was quite dangerous, they used this black silicone that was tough as nails. I had to use the BIG cutters to get enough off to pull the wire out and then practically drill through it with the soldering GUN to get the wire off, and I am talking a Weller 8200 which was 100/140 watts. Sometimes bent the tip getting through that shit.   I imagine that with some of the properties of the "good" silicone made the manufacturing process more expensive so they decided to use a low grade. Look at the application, it is not an insulator and not made to exposed to high voltage or high heat. Why would they use top grade stuff when it is not needed ?   I remember talking with an aircraft engineer as I was working on his PC. We got to bullshitting a bit and he explained that part of what he does is the stress formulae so they can shave off a little material here and there and save some weight. I was not as learned at the time and asked "Why not just make the whole thing out of titanium" and he said it doesn't work that way. One of the main reasons is that it is a bitch to machine.   However my engineer buddy I met a couple years ago does this stuff, actually designed dies and molds to make the impellers for jet engines. Recently he had a gig improving of all things, pain spray heads. He was surprised to find out how involved it is. they had a falling out and I think he is going to wind up doing contract work for Alcoa next but, the things he told me about what seems like a simple thing were quite interesting.   This is not a can of fucking Rustoleum here. This is what paints new cars and refrigerators or what have you. It is done with the electrostatic process which the charge literally pulls the paint to the piece, there is no overspray. But then this spray head turns at 70,000 RPM. So it is whipping the pain all around and the electrical charge reconcentrates it. Each spray head is thousads of dollars and that company rebuilds them. He redesigned them and made the process a whole lot easier and I think now they manufacture them, using his design. Like I said they had a falling out, he gave them a two week notice and they said don't bother. Probably because he was in a very good position to sabotage them. Not that he would, but how do they know that ?   Back to the subject, I agree, I have never seen any type of silicone melt. I have seen it burn but it take a hell off alot to get it going. But if these things work then they do. Being low grade most likely I would not expect them to last alot longer, but then if you are putting belts for the first time on something that is ten years old who cares ? As long as you don't put a soldering iron to them they will probably work fine.

N_Cook <diverse@tcp.co.uk>: Sep 14 07:40AM +0100 > However my engineer buddy I met a couple years ago does this stuff, actually designed dies and molds to make the impellers for jet engines. Recently he had a gig improving of all things, pain spray heads. He was surprised to find out how involved it is. they had a falling out and I think he is going to wind up doing contract work for Alcoa next but, the things he told me about what seems like a simple thing were quite interesting.   > This is not a can of fucking Rustoleum here. This is what paints new cars and refrigerators or what have you. It is done with the electrostatic process which the charge literally pulls the paint to the piece, there is no overspray. But then this spray head turns at 70,000 RPM. So it is whipping the pain all around and the electrical charge reconcentrates it. Each spray head is thousads of dollars and that company rebuilds them. He redesigned them and made the process a whole lot easier and I think now they manufacture them, using his design. Like I said they had a falling out, he gave them a two week notice and they said don't bother. Probably because he was in a very good position to sabotage them. Not that he would, but how do they know that ?   > Back to the subject, I agree, I have never seen any type of silicone melt. I have seen it burn but it take a hell off alot to get it going. But if these things work then they do. Being low grade most likely I would not expect them to last alot longer, but then if you are putting belts for the first time on something that is ten years old who cares ? As long as you don't put a soldering iron to them they will probably work fine.   I can just give it a go. People are just so grateful to find someone who will look at their old cassette unit, let alone repair it. Tell them its a trial material and may not last the 30 years of their original. For this use of silicone, I wonder about its continuing flexing in a dynamic use, but returning units the bands I've replaced in perhaps 5 years are fine, its other problems t5hat have emerged. I usually find silicone rubber ges friable on escessive heating and then breaks up, rather than melting

Phil Allison <pallison49@gmail.com>: Sep 13 07:26PM -0700 Tim Schwartz wrote:   > same question to came up with this link from Alps:   > http://www.alps.com/prod/info/E/PDF/Switch/Power/SAFETY.PDF   > The 3rd page has what I was looking for.   ** Fraid that page is highly misleading about what TV ratings mean.   The "TV" code is used by UL to identify switches that have a very high inrush surge current, endurance and fire safety performance. Such switches are suited to large halogen lamp loads and devices with large iron transformers.   Typical codes are TV5, TV8 or TV10 where the number refers to the steady rms on current for 25,000 operations with over 100Amp surges.   See link for useful examples:   http://www.nkkswitches.com/pdf/JP.pdf     .... Phil

Ralph Mowery <rmowery28146@earthlink.net>: Sep 13 12:03PM -0400 In article <5Z-dnYBSZNMolkXKnZ2dnUU7-IWdnZ2d@supernews.com>, pcdhSpamMeSenseless@electrooptical.net says...   .   > My Tek ones allow you to disable it by holding down a button as you turn > the meter on. I think the Fluke 87 does too. (I bought mine in 1988.)   I don't know all the model numbers, but the Flukes I have will allow you to keep them on by pressing a button when turned on.

Paul <nospam@needed.invalid>: Sep 13 01:28PM -0400 Mr. Man-wai Chang wrote:   > Isn't it silly in the very beginning? :)   Hey, Battery-Man, you'll be pleased to note they're truncating the charge cycle to 60%. This is to enhance safety for those people too stupid to participate in the recall effort. (You know, the same people here who drive their cars forever, on the spare wheel they found in the trunk of their car. Those people.)   http://www.cbc.ca/news/technology/samsung-galaxy-note-7-recharge-1.3759648   That means, they'll be avoiding Stage 2 completely. And checking the fill state (somehow) to determine when to stop. You cannot use time alone to do that (like stop at 45 minutes), because if the battery is at 40%, and the target is to charge to 60%, they need to use the "fuel gauge" to tell when to stop.   http://batteryuniversity.com/_img/content/ion1.jpg   I have no idea how they're doing that, whether the battery management chip is programmable, or the poor CPU will have to be on for the entire charging process. And return to the run-state, if the charger enters Stage 4 and tries to top up the battery later.   Paul

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