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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#41
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Eeyore wrote in message
... Jan Panteltje wrote: Joe Chisolm wrote Dr Howard Johnson (High Speed Digital Design) had this article in his email newsletter (and posted on his site). Interesting read. Rollback RoHS: http://www.sigcon.com/Pubs/news/10_01.htm Well seems [all] we have to [do is] make some traces .65mm apart :-) Some ? ALL ! Goodbye microelectronics. I just came across this too. http://en.wikipedia.org/wiki/Tin_pest " At 13.2 degrees Celsius (about 56 degrees Fahrenheit) and below, pure tin transforms from the (silvery, ductile) allotrope of beta-modification white tin to brittle, alpha-modification grey tin. Eventually it decomposes into powder, hence the name tin pest." Graham So when I pull , with just finger tension, a component lead through what was a lead-free solder joint only a year or so before and there is a grey powdery looking surface to the lead where it had been inside the solder joint - is that "tin pest" ? -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#42
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![]() N Cook wrote: Eeyore wrote I just came across this too. http://en.wikipedia.org/wiki/Tin_pest " At 13.2 degrees Celsius (about 56 degrees Fahrenheit) and below, pure tin transforms from the (silvery, ductile) allotrope of beta-modification white tin to brittle, alpha-modification grey tin. Eventually it decomposes into powder, hence the name tin pest." So when I pull , with just finger tension, a component lead through what was a lead-free solder joint only a year or so before and there is a grey powdery looking surface to the lead where it had been inside the solder joint - is that "tin pest" ? It could well be I suppose. Here's the problem, we're in 'uncharted territory' here because the EU insisted on going down this path before the science was well-established. Document it. It has serious implications for the classic practice of keeping MI gear in the van / truck, in the (unheated) garage etc. I'd love to see the idiots at the Commision in Brussels forced to eat humble pie. It's about time that Emperor Barroso's new clothes were seen for what they are. Graham |
#43
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![]() Alex wrote: I reworked all the joints with lead-free, as that is what the RoHS legislation legally charges me to do as a commercial repair outfit, but boy, the temptation was strong to just reach for the leaded solder, and do the job 'properly' ... If you use leadfree solder, remember that the temperature is a bit higher, and this makes the fumes from resin much more dangerous to YOU.. Second.. if the components is made for leadfree solder , it can happen that the tin/lead solder wont make a good solder-joint. ( but I agree that sometimes one is tempted ) Do you always talk **** ? Graham |
#44
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On Jul 25, 1:48 pm, msg wrote:
Jan Panteltje wrote: snip How about conductive glue replacing solder? Na, will have to wait until the first EU politician's cellphone fails in some emergency. What ever happened to 'multiwire' (or some such trade name)? It was a multilayered weld-bonded wiring alternative to multilayer PCBs in the '60s and '70s and was very rugged, easily implemented with NC technology, and used no solder of course. Since each layer is built up in succession, between power and ground planes, even BGAs can be accomodated. You just named the problem with Multiwire--wire is sequentially applied to a thermoplastic substrate. Whatever other advantages or problems it may have, it is a *prototyping* process, not a mass production process. It is to PCB production as e-beam is to photolithography. |
#45
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![]() "Eeyore" wrote in message ... The debate about lead free solders seem to be nearly as politically charged as that about anthropogenic global warming and a casualty seems to be useful data. I've read plenty of comments to the effect that lead-free is less reliable in the long term (vibration seems to be a key weakness AIUI - maybe also thermal cycling) which presumably explains the exemptions for certain categories, yet I've also seen some studies that claim it can out-perform lead containing solders. Is there any real hard and fast information out there that one can rely on ? Graham Tin Whiskers:- For those who though leaded solder was best. Here is the problem with lead free solder. http://pubs.acs.org/cen/science/85/8529sci1.html Colin |
#46
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![]() "Glen Walpert" wrote in message ... On Tue, 24 Jul 2007 23:42:47 +0100, Eeyore wrote: The debate about lead free solders seem to be nearly as politically charged as that about anthropogenic global warming and a casualty seems to be useful data. I've read plenty of comments to the effect that lead-free is less reliable in the long term (vibration seems to be a key weakness AIUI - maybe also thermal cycling) which presumably explains the exemptions for certain categories, yet I've also seen some studies that claim it can out-perform lead containing solders. Is there any real hard and fast information out there that one can rely on ? Graham Don't look to this newsgroup for factual info on lead free! Instead look at actual test results in the trade publications such as SMT magazine: http://smt.pennnet.com/home.cfm They have published numerous tests comparing various lead free materials and processes with tin-lead. Some lead free materials and processes are better than others (no surprise) and picking the best one for your situation is non-trivial. My nutshell summary of the published test results is that lead free is significantly harder to do right than tin-lead, requiring tighter process controls, but if done right it can be more reliable than tin-lead for non-shock situations. Lead free is harder, stronger and more brittle than tin-lead so tin-lead will deform plastically under high shock when lead free will break, however lead free will withstand more hot-cold cycles than before failure than tin-lead (better fatigue resistance). So you need to know what the significant failure mechanisms are in your design to pick the most reliable materials. Glen And in the meantime whilst smaller manufacturers who don't have the resources of the big boys to research this crap in sufficient detail to find the 'correct' process to replace the previously utterly reliable and simple leaded soldering that they were using, cartloads of electronic equipment are failing as a result of the bad joints that the experimentation or 'best fit' replacement alloys are causing. I wonder what qualifies you to make that remark at the beginning of your post, telling people not to look to this group for 'factual' information on lead-free ? When I tell you that I work day in day out with equipment from major manufacturers that uses the stuff, and that since they have been using it, I have seen the incidence of bad joints in places that would never previously have suffered, skyrocket, do you consider that to not be 'factual' ? Am I lying perhaps ? There are many good engineers that contribute to this group, and most have reported seeing an increase in such bad joints. Are they all being less than 'factual' ? When push comes to shove, this is an electronic repair group, frequented by, amongst others, repair professionals who have to deal with the effects of legislation such as RoHS, and its implications, at the sharp end, which is more than the manufacturers and political activists / pseudo scientists responsible for creating these situations, do. As such, I feel that it is therefore rather presumptuous of you to suggest that opinions voiced on this group, are not based in fact, and thus not valid. Arfa |
#47
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On Wed, 25 Jul 2007 10:41:01 +0100, "N Cook" wrote:
Spurious Response wrote in message news ![]() On Wed, 25 Jul 2007 08:42:50 +0100, "N Cook" wrote: Military , aerospace & medical do have derogation from WEEE and RoSH, but can anyone nail down precisely why they are exempted. Absolutely. Lead based solder alloys are ****ing superior, and Tin based, non-leaded alloys are inferior, and have VERY POOR reliability numbers. It is really quite simple math. A mission critical application REQUIRES a system where one does not have to expect some lame failure mode to creep in due to the utilization of a VERY POOR, failure mode prone device interconnection methodology. The next time I get a year or 2 year old 800 GBP/1500 USD combo in for repair with loose simple, thermally un-stressed,but vibrationally stressed components, I will actually measure the extraction force of the obviously suspect ones and some of the remaining ones, with a spring balance and a hook of wire. I would never have expected otherwise well-soldered (but obviously lead-free solder) very basic "components" like soldered wire links,1/3W resistors,TO92 transistors, to have solder failures after decades, let alone a couple of years. Most "solder creep" (the expression which describes your scenario) failures can be tracked back to a poor design as it relates to fixturing large masses or "tugged on" components or interconnects. Such elements should be fixtured by means other than the soldered leads. It was unclear to me whether your situation was a remark about how quickly a lead free assembly exhibits such failure, or about older. leaded solder alloys in assemblies. Some more relevant background text from http://www.lboro.ac.uk/research/iemr...202015%20Makin g%20a%20Visible%20Difference%20EIGT%20Report.pd f nothing about failure rates in the bullet-points though Cool. "..... The lead-free solder proposal was introduced at short notice by the EU in 1998 as a revision to the WEEE Directive under Article 175 (environment), and is the subject of qualified majority voting, so the UK has no power of veto. The UK was the only member state represented by its industry ministry, and other member states were represented by environmental ministries. No rigorous fiche d'impact was undertaken. The proposals take effect from 1 July 2006. Yep. Subsequently, the Removal of Hazardous Substances (RoHS) provisions, which deal with other hazardous substances, were made under Article 95 (single market). So interdependent legislation will be introduced under different agreement arrangements. Unintended consequences include: * Increased material and component costs because some PCB material and some components cannot be used with higher temperature solder; * Re-certification costs for safety critical products; * Damage to soldering equipment from electrochemical corrosion, following use of tin-rich solder in machines previously used with lead- based solder; * Increased capital equipment cost as equipment life shortens; * Increased costs associated with inspection, testing and tracking to demonstrate compliance; * Training and retraining costs for staff working with new materials; * Increased capital and inventory costs as manufacturers keep separate lines and stocks for defence and exempt products. ....." And for solder, it was entirely NOT necessary. The other substances perhaps, but not for solder. |
#48
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On Wed, 25 Jul 2007 10:41:13 +0100, Eeyore
wrote: Spurious Response wrote: "N Cook" wrote: Military , aerospace & medical do have derogation from WEEE and RoSH, but can anyone nail down precisely why they are exempted. Absolutely. Lead based solder alloys are ****ing superior, and Tin based, non-leaded alloys are inferior, and have VERY POOR reliability numbers. It is really quite simple math. A mission critical application REQUIRES a system where one does not have to expect some lame failure mode to creep in due to the utilization of a VERY POOR, failure mode prone device interconnection methodology. So pony up your data ! "Data" is a collection of values or attributes for a given observation. "Information" is processed data. What you are looking for is information. |
#49
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![]() "Arfa Daily" wrote in message ... "Eeyore" wrote in message ... Spurious Response wrote: Eeyore wrote: "Leeper" wrote: t is really application and chip package specific, Bull****. Lead based solder alloys are superior in damn near all electronic realms, and there is no configuration where they would not be other than high end commercial and military applications, and they certainly do not include Tin. Whilst I don't disagree with you, where's the hard comparative data ? Considering the fact that we have 5 decade old circuit cards still operating perfectly, and that we already know what alloys containing Tin which is not bound by Lead do over time and temperature cycling, I do not think that precise numerical analysis is even needed on such a profoundly lopsided issue. Whilst I agree with you, bureacrats tend not to be very receptive to anecdotal comment. And make no mistake, the bureacrats are the ones in control of this. Graham I have just this minute finished repairing a Panasonic DAB / FM radio which was dying as soon as it was switched on, with a "F76 Pdet" error in the display. I took this to be "power detect", which seemed reasonable, given the symptoms. When I took the main board out to have a look at the underside, I found the power supply section riddled with poor and 'cracked-right-round' lead-free solder joints ( the board actually has "PbF" silk-screened on it ). The poor joints were particularly well defined on the main free-air cooled regulator transistor, which is obviously subject to thermal cycling. I reworked all the joints with lead-free, as that is what the RoHS legislation legally charges me to do as a commercial repair outfit, but boy, the temptation was strong to just reach for the leaded solder, and do the job 'properly' ... But we know which solder you really used. Of course, you have to pretend you used the PbF stuff. Just be careful that the lead nazis don't audit your purchasing of lead content... Leonard |
#50
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On Wed, 25 Jul 2007 10:43:08 +0100, Eeyore
wrote: Spurious Response wrote: Eeyore wrote: "Leeper" wrote: t is really application and chip package specific, Bull****. Lead based solder alloys are superior in damn near all electronic realms, and there is no configuration where they would not be other than high end commercial and military applications, and they certainly do not include Tin. Whilst I don't disagree with you, where's the hard comparative data ? Considering the fact that we have 5 decade old circuit cards still operating perfectly, and that we already know what alloys containing Tin which is not bound by Lead do over time and temperature cycling, I do not think that precise numerical analysis is even needed on such a profoundly lopsided issue. Whilst I agree with you, bureacrats tend not to be very receptive to anecdotal comment. And make no mistake, the bureacrats are the ones in control of this. If the water tables around an outdoor shooting range had any higher levels of lead leeched into them, the whole world would know about it, and that is what we call NEWS. FACT is that there is no such lead level increase in such areas, and they dump TONS of lead into the ground at popular ranges. FACT is that I have been touching, rubbing, etc. lead alloy soldered circuit card assemblies (as well as the solder itself) my entire adult life, and my lead levels are lower than the doc had previously seen for someone my age, the last time I had that test taken ( about four years ago). |
#51
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![]() "mpm" wrote in message oups.com... And that's if Global Warming doesn't get us first... If you believe that to be a possibility, are you not concerned about the additional carbon based fuels used to heat these lead free solders to the higher temperatures that they require? Leonard |
#52
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On Wed, 25 Jul 2007 10:45:30 +0100, Eeyore
wrote: Spurious Response wrote: Eeyore wrote: Personally, I can think of no good reason to attempt to 'recycle' old printed circuit boards. For example it appears to be both uneconomic and likely energy wasteful too. If one (read a business) had an incinerator for refuse, which is common in the US, one could very easily have enough heat energy "left over" to reflow, and "Smack and Gather" soldered assemblies after they reach reflow temperatures. It would not take long to gather a ton of "solder". A ton is a ton is a ton, and gathering several grams from each assembly one has for salvage makes the planet more "green", because reprocessing lead, and lead alloys is far easier and less costly than mining it. Incinerators are now deprecated since the greenies say they make dioxins. Fully operating incinerators are sprinkled all over this country. There was even some twit on TV the other day claiming that their placement was racist. Actually, I'd expect a lot of solder to turn to oxides and go up the smoke stack if subjected to high temps. Do you know the rate that pure Lead oxidizes? Do you know the rate at which 63/37 Tin Lead Solder oxidizes at? Bullets are still being found in old US Civil War battle fields, and they are practically pristine balls. No crust whatsoever. What actually happens with pure Lead is that it's first few mils of depth become "tempered", similar to aluminum anodization. So it becomes harder, and would oxidize even less. |
#53
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On Wed, 25 Jul 2007 12:28:58 +0100, "N Cook" wrote:
If you had not repaired it than also no doubt it would have ended in landfill taking with it ,perhaps not lead, but antimony, bismuth, tin, copper, barium , phthalates etc And lead free utilization does exactly what against these elements and compounds? |
#54
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On Wed, 25 Jul 2007 15:57:34 GMT, Jan Panteltje
wrote: On a sunny day (Wed, 25 Jul 2007 08:33:12 -0700) it happened mpm wrote in s.com: On Jul 25, 3:42?am, "N Cook" wrote: Follow the derogations/exemptions. Military , aerospace & medical do have derogation from WEEE and RoSH, but can anyone nail down precisely why they are exempted. I suspect it is because these fields are considered "life-safety" fields. Even ordinance, when you think of it in terms of friendly fire incidents. They probably just don't want to recertify their processes, or don't have the time to do it right. But the "Truth"? That's much more elusive. Does RoHS result in a better environment? I don't know, but I doubt it. The sheer number of TV sets that will be obsoleted in the coming years due to the migration to Digital Television will probably swamp the RoHS "gains" by orders of magnitude. Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. |
#55
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![]() Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Graham |
#56
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On Wed, 25 Jul 2007 19:03:35 +0100, Eeyore
wrote: Jan Panteltje wrote: Joe Chisolm wrote Dr Howard Johnson (High Speed Digital Design) had this article in his email newsletter (and posted on his site). Interesting read. Rollback RoHS: http://www.sigcon.com/Pubs/news/10_01.htm Well seems [all] we have to [do is] make some traces .65mm apart :-) Some ? ALL ! Goodbye microelectronics. I just came across this too. http://en.wikipedia.org/wiki/Tin_pest " At 13.2 degrees Celsius (about 56 degrees Fahrenheit) and below, pure tin transforms from the (silvery, ductile) allotrope of beta-modification white tin to brittle, alpha-modification grey tin. Eventually it decomposes into powder, hence the name tin pest." That's what cost Napoleon dearly in Russia. He lost his armies to exposure due to their uniforms literally falling off their bodies. All Tin buttons, even on their boots. http://ds.dial.pipex.com/town/terrac...nce/moscow.htm |
#57
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![]() "Leonard Caillouet" wrote in message ... "Arfa Daily" wrote in message ... "Eeyore" wrote in message ... Spurious Response wrote: Eeyore wrote: "Leeper" wrote: t is really application and chip package specific, Bull****. Lead based solder alloys are superior in damn near all electronic realms, and there is no configuration where they would not be other than high end commercial and military applications, and they certainly do not include Tin. Whilst I don't disagree with you, where's the hard comparative data ? Considering the fact that we have 5 decade old circuit cards still operating perfectly, and that we already know what alloys containing Tin which is not bound by Lead do over time and temperature cycling, I do not think that precise numerical analysis is even needed on such a profoundly lopsided issue. Whilst I agree with you, bureacrats tend not to be very receptive to anecdotal comment. And make no mistake, the bureacrats are the ones in control of this. Graham I have just this minute finished repairing a Panasonic DAB / FM radio which was dying as soon as it was switched on, with a "F76 Pdet" error in the display. I took this to be "power detect", which seemed reasonable, given the symptoms. When I took the main board out to have a look at the underside, I found the power supply section riddled with poor and 'cracked-right-round' lead-free solder joints ( the board actually has "PbF" silk-screened on it ). The poor joints were particularly well defined on the main free-air cooled regulator transistor, which is obviously subject to thermal cycling. I reworked all the joints with lead-free, as that is what the RoHS legislation legally charges me to do as a commercial repair outfit, but boy, the temptation was strong to just reach for the leaded solder, and do the job 'properly' ... But we know which solder you really used. Of course, you have to pretend you used the PbF stuff. Just be careful that the lead nazis don't audit your purchasing of lead content... Leonard Afraid not, Leonard. I take my responsibilities under the law, seriously. I always rework lead-free joints with lead-free solder, as I am required to do. Perhaps I am silly for doing so, and it's not to say that I don't think that I am compounding poor construction techniques with a poor repair, but never-the-less, I do comply. Of course, a great deal of the kit that I work on is constructed with leaded solder as it pre-dates the legislation, and for those repairs, I do indeed use my SnPb solder inventory ... d;~} Arfa |
#58
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On Wed, 25 Jul 2007 19:26:58 GMT, Jan Panteltje
wrote: Too bad.... How about conductive glue replacing solder? Na, will have to wait until the first EU politician's cellphone fails in some emergency. There have been polymer based conductive circuit assembly adhesives around for several years now. NOT cheap. The answer will be Rhodium alloy solders for safety and mission critical applications... perhaps. |
#59
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On Wed, 25 Jul 2007 21:56:53 +0100, Eeyore
wrote: msg wrote: Jan Panteltje wrote: snip How about conductive glue replacing solder? Na, will have to wait until the first EU politician's cellphone fails in some emergency. What ever happened to 'multiwire' (or some such trade name)? It was a multilayered weld-bonded wiring alternative to multilayer PCBs in the '60s and '70s and was very rugged, easily implemented with NC technology, and used no solder of course. Gone the same way as wire wrap it seems. Graham Most VME backplanes utilize a press fit pin, directly into a clad hole, and it is gas tight in the connection regions and there is no solder involved. Lasts for years and years. |
#60
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![]() "Traver" wrote in message ups.com... On Jul 25, 1:29 pm, Joe Chisolm wrote: On Tue, 24 Jul 2007 23:42:47 +0100, Eeyore wrote: The debate about lead free solders seem to be nearly as politically charged as that about anthropogenic global warming and a casualty seems to be useful data. I've read plenty of comments to the effect that lead-free is less reliable in the long term (vibration seems to be a key weakness AIUI - maybe also thermal cycling) which presumably explains the exemptions for certain categories, yet I've also seen some studies that claim it can out-perform lead containing solders. Is there any real hard and fast information out there that one can rely on ? The main issue for lead free in military and aerospace electronics is tin whiskers. Tin solder will grow conductive whiskers that even penetrate conformal coatings. In low power circuit, the whisker will short something out. In a high power circuit, it might burn up like a fuse, but if it happens in a satellite (no atmospheric pressure) the little whisker will cause a plasma arc capable of passing huge amounts of current. We in the defense electonics industry fight with this issue every day and the information is very confusing. Parts turn lead free midstream in production and seems impossible to keep tack of it. Every company is dealing with it differently. We stay away from certain finishes like bright tin and look at the spacing of components and coatings on our boards. This can mitigate some of the reliability risks of lead free. If high-rel is of upmost importance, we struggle to find tin-lead parts. That's worrying ... Arfa |
#61
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![]() "Eeyore" wrote in message ... Allodoxaphobia wrote: Eeyore wrote: The debate about lead free solders seem to be nearly as politically charged as that about anthropogenic global warming and a casualty seems to be useful data. More than political -- the subject could easily be viewed as troll bait. It's been 'discussed' many times in ser. It's not a troll. New data ought be available as to the effects on actual in-service reliability of lead-free by now. It seems as I expected, anecdotally, that musical equipment products that tend to see high levels of vibration are suffering. Graham As are most other products that are *not* subject to excessive amounts of vibration. Arfa |
#62
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On Wed, 25 Jul 2007 19:47:40 -0400, "Leonard Caillouet"
wrote: "mpm" wrote in message roups.com... And that's if Global Warming doesn't get us first... If you believe that to be a possibility, are you not concerned about the additional carbon based fuels used to heat these lead free solders to the higher temperatures that they require? Good one. |
#63
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On Thu, 26 Jul 2007 01:41:33 +0100, Eeyore
wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Graham Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. |
#64
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![]() "Colin Horsley" wrote in message ... "Eeyore" wrote in message ... The debate about lead free solders seem to be nearly as politically charged as that about anthropogenic global warming and a casualty seems to be useful data. I've read plenty of comments to the effect that lead-free is less reliable in the long term (vibration seems to be a key weakness AIUI - maybe also thermal cycling) which presumably explains the exemptions for certain categories, yet I've also seen some studies that claim it can out-perform lead containing solders. Is there any real hard and fast information out there that one can rely on ? Graham Tin Whiskers:- For those who though leaded solder was best. Here is the problem with lead free solder. http://pubs.acs.org/cen/science/85/8529sci1.html Colin Yes, a good write-up of the problems, and why leaded solder didn't suffer from them. Arfa |
#65
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![]() Spurious Response wrote: Eeyore wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. I have a cable TV set top box. There's no tuning involved. It still breaks up occasionally. Graham |
#66
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![]() Spurious Response wrote: Eeyore wrote: Jan Panteltje wrote: Joe Chisolm wrote Dr Howard Johnson (High Speed Digital Design) had this article in his email newsletter (and posted on his site). Interesting read. Rollback RoHS: http://www.sigcon.com/Pubs/news/10_01.htm Well seems [all] we have to [do is] make some traces .65mm apart :-) Some ? ALL ! Goodbye microelectronics. I just came across this too. http://en.wikipedia.org/wiki/Tin_pest " At 13.2 degrees Celsius (about 56 degrees Fahrenheit) and below, pure tin transforms from the (silvery, ductile) allotrope of beta-modification white tin to brittle, alpha-modification grey tin. Eventually it decomposes into powder, hence the name tin pest." That's what cost Napoleon dearly in Russia. He lost his armies to exposure due to their uniforms literally falling off their bodies. All Tin buttons, even on their boots. http://ds.dial.pipex.com/town/terrac...nce/moscow.htm Oh, I recall it now. It seems that the Open University has studied this issue and has indeed found tin pest in 'cheap' lead-free solders that are 99%+ tin. These are in commercial use too ! http://materials.open.ac.uk/srg/srg_tp.htm The question next should be whether the popular SAC alloys are affected. Graham |
#67
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On Thu, 26 Jul 2007 02:37:53 +0100, Eeyore
wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. I have a cable TV set top box. There's no tuning involved. It still breaks up occasionally. IT tunes itself, dip****. Do you actually think I meant that you had a knob to turn? Get your head out of your twenty year behind the digitally tuned receiver world ass. OK... I'll spell it out for you. If it ACQUIRES the signal, and locks it in, it gets ALL packets from the HEAVILY FEC coded stream, and can handle up to a 10% bit error rate before the "tuning" starts to lose, and not be able to repair with the FEC, data packets. When that happens, one starts to lose audio and or video or could see some video artifacts. It usually results in short term. low frame count dropouts. So it isn't "breaking up". That is an analog expression. In digital broadcast streams, the term is "dropout". |
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On Thu, 26 Jul 2007 06:18:27 +0100, Eeyore
wrote: The question next should be whether the popular SAC alloys are affected. Graham I didn't read that cite I posted a link to well enough. It barely mentions it. http://ap.pennnet.com/Articles/Artic...ICLE_ID=216209 |
#69
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![]() Spurious Response wrote: Eeyore wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. I have a cable TV set top box. There's no tuning involved. It still breaks up occasionally. IT tunes itself, dip****. Which part of " There's no tuning involved " didn't you understand ? You press a button, it gives you the channel. Of course I know it does any internal tuning required in firmware. Graham |
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![]() Spurious Response wrote: So it isn't "breaking up". Yes it 'breaks up'. Typically with weird pixellation. That is an analog expression. No it isn't. In digital broadcast streams, the term is "dropout". No, a dropout is a momentary LOSS of signal. Graham |
#71
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On Thu, 26 Jul 2007 06:49:56 +0100, Eeyore
wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. I have a cable TV set top box. There's no tuning involved. It still breaks up occasionally. IT tunes itself, dip****. Which part of " There's no tuning involved " didn't you understand ? Except that you made the ****ing stupid remark as if you were attempting to "educate" me. Nice back pedal though. You press a button, it gives you the channel. Of course I know it does any internal tuning required in firmware. You didn't grasp the post though, and made the remark unnecessarily. |
#72
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On Thu, 26 Jul 2007 06:52:25 +0100, Eeyore
wrote: Spurious Response wrote: So it isn't "breaking up". Yes it 'breaks up'. Typically with weird pixellation. That is an analog expression. No it isn't. In digital broadcast streams, the term is "dropout". No, a dropout is a momentary LOSS of signal. No. In HDTV broadcast, "dropout" is when a tuned station has more than about 10% bit error rate, and the FEC cannot repair the data stream, and everything from a few picture artifacts appears, to complete frame losses (dropouts) occur. The picture artifacts are also dropouts, just not those that cause the tuning device to display a blank screen for that given frame, which they do when it gets beyond a certain point. If they wanted to, they could show you the frames, and you would see horrendous amounts of image artifacts, and likely audio problems as well. It IS called dropout. Lost packets ARE lost "signal" as the packet would not have been lost, were it not for the tuner's inability to reconstruct any missing packet data from the FEC coding. This has been true from way back in the early satellite receiver days. Videocipher http://en.wikipedia.org/wiki/Videocipher Digicipher II (most closely related to the new HDTV broadcast schema). http://en.wikipedia.org/wiki/DigiCipher_2 The current HDTV broadcast schema is also a General Instrument format, now owned by Motorola. |
#73
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On a sunny day (Wed, 25 Jul 2007 17:05:06 -0700) it happened Spurious Response
wrote in : Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. The boxes that are sold here are equipped with a SCART connector, a waste. My 30 year old portable has no SCART, and neither is it HDTV (high resolution). HDTV is here only available in HDMI DHCP, and still rare anyways. The normal broadcasting on 'digitenne' here is not HDTV, but DVB-T 720x576. The idea of a 'portable' is that you bring it to the camping, switch it on, and see the picture. This fails now for many portables. I am watching digital TV via the PC for satellite, and also via USB with a settop box for terrestrial. This allows me to record transport-stream, burn to DVD, automate things, etc. I have not seen any digitenne portable TVs yet, but I am sure the market will soon overflow with these. I do see a lot of very cheap analog TVs for sale :-) What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. mmm, it is actually not so simple, for example with satellite we now are moving from DVB-S to DVB-S2, and also from 720x576 to 1980x1080 interlaced or progressive, all with HDCP / HDMI..... using MPEG4 / H264 with some sort of audio, well we have now mp2, AC3, more to follow..... That, and your sets fall apart after 3 years because of lead-free, it is a great time for manufacturers of electronics consumers stuff now ain't it? Not even to mention Blu-ray versus HD-DVD or whatever, no connector fits.... no format is the same.... It is a wild wild world out there :-) |
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On a sunny day (Wed, 25 Jul 2007 15:48:39 -0500) it happened msg
wrote in : Jan Panteltje wrote: snip How about conductive glue replacing solder? Na, will have to wait until the first EU politician's cellphone fails in some emergency. What ever happened to 'multiwire' (or some such trade name)? It was a multilayered weld-bonded wiring alternative to multilayer PCBs in the '60s and '70s and was very rugged, easily implemented with NC technology, and used no solder of course. Since each layer is built up in succession, between power and ground planes, even BGAs can be accomodated. Regards, Michael Never heard of it, sound OK though. |
#75
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![]() Spurious Response wrote: Eeyore wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: Eeyore wrote: Spurious Response wrote: What is nice about digital broadcasts is that when you have the signal, you have it all. No snow, No herringbone patterns. Crisp and clean, with no caffeine. Except when it breaks up. Nope. If you tune the signal, you get ALL of the data. You must exceed more than ten percent bit error rate for a dropout to occur, and it is bit error rate that matters most for a "tuned" channel. I have a cable TV set top box. There's no tuning involved. It still breaks up occasionally. IT tunes itself, dip****. Which part of " There's no tuning involved " didn't you understand ? Except that you made the ****ing stupid remark as if you were attempting to "educate" me. Nice back pedal though. Repeating myself (for emphasis) is backpedalling is it ? What a curious view you have of the world. You press a button, it gives you the channel. Of course I know it does any internal tuning required in firmware. You didn't grasp the post though, and made the remark unnecessarily. Don't be absurd. Graham |
#76
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![]() Spurious Response wrote: Eeyore wrote: Spurious Response wrote: So it isn't "breaking up". Yes it 'breaks up'. Typically with weird pixellation. That is an analog expression. No it isn't. In digital broadcast streams, the term is "dropout". No, a dropout is a momentary LOSS of signal. No. In HDTV broadcast, "dropout" is when a tuned station has more than about 10% bit error rate, and the FEC cannot repair the data stream, and everything from a few picture artifacts appears, to complete frame losses (dropouts) occur. The picture artifacts are also dropouts, just not those that cause the tuning device to display a blank screen for that given frame, which they do when it gets beyond a certain point. If they wanted to, they could show you the frames, and you would see horrendous amounts of image artifacts, and likely audio problems as well. It IS called dropout. Lost packets ARE lost "signal" as the packet would not have been lost, were it not for the tuner's inability to reconstruct any missing packet data from the FEC coding. This has been true from way back in the early satellite receiver days. Videocipher http://en.wikipedia.org/wiki/Videocipher Digicipher II (most closely related to the new HDTV broadcast schema). http://en.wikipedia.org/wiki/DigiCipher_2 The current HDTV broadcast schema is also a General Instrument format, now owned by Motorola. Thanks for playing. It is like taking candy from a baby though. Graham |
#77
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![]() Jan Panteltje wrote: Spurious Response wrote Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. The boxes that are sold here are equipped with a SCART connector, a waste. I imagine you haven't looked very hard in that case. Many have UHF outputs. Graham |
#78
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konijne keutel Eeyore wrote in
: Jan Panteltje wrote: Spurious Response wrote Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. The boxes that are sold here are equipped with a SCART connector, a waste. I imagine you haven't looked very hard in that case. Many have UHF outputs. Graham If you had as much as a clue, did not cut half the posting, knew at least half as much about TV as about rabbits, you would be chaising them. |
#79
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![]() Jan Panteltje wrote: Eeyore wrote Jan Panteltje wrote: Spurious Response wrote Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. The boxes that are sold here are equipped with a SCART connector, a waste. I imagine you haven't looked very hard in that case. Many have UHF outputs. Graham If you had as much as a clue, did not cut half the posting I wasn't replying to the bits I trimmed. Graham |
#80
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The one who calls himself rabbitsfriendsandrelations wrote:
Jan Panteltje wrote: Eeyore wrote Jan Panteltje wrote: Spurious Response wrote Right, I turned in a portable TV last week. This one was about 30 years old (seventies), and was still working OK, but no analog transmissions here anymore, all you get is nice equal distributed noise when tuning in to a digital station. There are SEVERAL HDTV set top tuners out there that will pipe the finished signal into a standard TV. The boxes that are sold here are equipped with a SCART connector, a waste. I imagine you haven't looked very hard in that case. Many have UHF outputs. Graham If you had as much as a clue, did not cut half the posting I wasn't replying to the bits I trimmed. Graham To enlighten the others: to buy anything with any sort of analog output sucks, as analog is dead at least here in the Netherlands (except for audio). Buying a settop box with USB output, if you have a laptop with USB, creates the portable TV with much better quality and recording possibility. The USB settop box I bought runs from a 12 V adapter, so also from a car battery. I researched quite a bit to get the best deal, and SCART was not part of that, let alone a horrible interference prone, PAL coding artefacts decorated UHF analog output. ftp://panteltje.com/pub/dvb-t-nl.txt |
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