Bad Omen?
in [Design]
|
Prev: DC motor opinion/question
Next: RPM Meter
From: Spehro Pefhany on 30 Jul 2010 07:07 On Thu, 29 Jul 2010 14:11:22 -0700, the renowned Joerg <invalid(a)invalid.invalid> wrote: >Spehro Pefhany wrote: >> On Thu, 29 Jul 2010 07:30:03 -0700, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Sergey Kubushyn wrote: >>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>> Sergey Kubushyn wrote: >>>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>>> Sergey Kubushyn wrote: >>>>>>>> Tim Williams <tmoranwms(a)charter.net> wrote: >>>>>>>>> "Martin Riddle" <martin_rid(a)verizon.net> wrote in message news:i2ntnv$o1h$1(a)news.eternal-september.org... >>>>>>>>>> Maybe they don't like paying 3x the price for those parts? >>>>>>>>> I don't know about that, I've shopped around and it's no worse than a factor of 2, with most of them being on par or better. >>>>>>>> As a matter of fact Mouser is not _THAT_ bad. It is almost on par with >>>>>>>> Arrow/Avnet/etc. Sometimes even cheaper. And in most cases their markup is >>>>>>>> less than 100%. >>>>>>>> >>>>>>>> That is another twin, DigiKey, that has everything marked up to the ears. I >>>>>>>> never understood why people do purchase anything from them... >>>>>>>> >>>>>>> Because they have the only search engine that works. >>>>>> Do they? >>>>> Oh yeah. None of the others comes even close. And they know it. >>>>> >>>>>> >>>>>> And another question -- even if they were so unique why would one start >>>>>> searching anything on DigiKey (or whatever be it Mouser/Allied/Arrow/etc?) >>>>>> >>>>> As I said, because I find stuff the fastest on Digikey. My clients have >>>>> to pay for my time on their projects and on their behalf I need to be >>>>> frugal with billed hours. Even if the parts for 2-3 prototypes end up >>>>> costing five bucks more that's peanuts compared to the frustrating extra >>>>> half hour on one of the other sites. >>>>> >>>>> >>>>>> It is much wiser to start with something like findchips.com or Octopart that >>>>>> would search _MULTIPLE_ sites for you and then you could choose which one to >>>>>> use... Octopart even has a FireFox plugin that installs alongside with >>>>>> Google and friends. >>>>>> >>>>> That only works if you already know what you want, down to the part >>>>> number. I often must peruse the selection, see what's there, high in >>>> Have you ever tried? You don't need a part number to search for e.g. "0.1uF >>>> Polypropylene Capacitor." That works on both findchips and octopart. And >>>> they show you what's in the inventory of major distributors. Including >>>> DigiKey :) >>>> >>> Ok then, go on Findchips, key in this: >>> >>> 0.1uF ceramic >>> >>> Then you know what I mean. According to the results most distributors >>> don't carry any. I guess that takes the cake. >> >> Well, it is called findchips. You have to go to findcaps.com for >> capacitors. >> > >The first category on there was "umbrellas". Hmmm ... :-) > > >> I like the hack that allows you to sort by price on Digikey (using >> Greasemonkey). Shame they don't incorporate it themselves. >> > >Hack? Where? Where? <pant ... pant> I use this with Firefox. Note that it has to load the pages first, so if you have scores of pages it might take a moment or two each time you search, even with a fast internet connection, but all-in-all it's a good thing. I generally leave it turned on all the time. http://students.washington.edu/acleone/codes/greasemonkey/digikey_sort_by_price/ Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: Joerg on 30 Jul 2010 10:28 Sergey Kubushyn wrote: > Joerg <invalid(a)invalid.invalid> wrote: >> Sergey Kubushyn wrote: >>> Joerg <invalid(a)invalid.invalid> wrote: >>>> Sergey Kubushyn wrote: >>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>> Sergey Kubushyn wrote: >>>>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>>>> Sergey Kubushyn wrote: >>>>>> [...] >>>>>>>>> Just one example--I recently tried to buy several thousands of >>>>>>>>> BC550/60C transistors. The funny thing was Avnet had BC560CTA @ $0.0163 >>>>>>>>> each but no BC550C at all. I bought 2 ammopacks of 2,000 for $65 from them >>>>>>>>> (that was all they had in stock.) On the other hand Arrow only had (and >>>>>>>>> still have) BC550CTA at the same price but no BC560C at all. That was a >>>>>>>>> couple of days ago. Now Avnet has 32K of BC550CTA in stock. If you were >>>>>>>>> shopping at Avnet only a week ago you would've said that BC550C are >>>>>>>>> unobtanium because they do not have them in stock while both findchips and >>>>>>>>> octopart kept telling Arrow has plenty in stock. >>>>>>>>> >>>>>>>> Just what I said all along, should have gone to Digikey, they have >>>>>>>> oodles of them: >>>>>>>> >>>>>>>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=BC550CGOS-ND >>>>>>> If you want to pay 3x the price, sure. And 7,055 pcs is not "oodles." And >>>>>>> even those are just remnants, the other BC550Cxx are non-stocked. And this >>>>>>> only one will also go non-stocked when they are bought. >>>>>>> >>>>>>> And they are exactly at the same point with BC560C. 4,000 left in stock at >>>>>>> 2x price and a big fat warning they will go non-stocked once that inventory >>>>>>> is sold. >>>>>>> >>>>>> Sergey, let's face it, nearly all thru-hole stuff is going to head for >>>>>> lalaland. Ok, we were really early adopters over in Europe back then, >>>>>> but since the start of my industrial career in 1986 I can't remember any >>>>>> thru-hole board I have designed. And I've designed tons of boards. >>>>>> >>>>>> There will always be mfgs for thru-hole, just like Sovtek and Svetlana >>>>>> do for tubes, but it's going to be boutique-ware. >>>>> That is what I'm using them for. Not with tubes but for audio. >>>>> >>>>> The rumours about their death are grossly exagerrated. Fairchild makes those >>>>> full steam and they are dirt cheap. Toshiba is back with their 2SK170 and >>>>> 2SK369 parts that were discontinued long ago. And those parts are TO-92. >>>>> BTW, Fairchild picked up a lot of Japanese transistors and now there is >>>>> plenty of 2SA/SB/SC parts in their lineup. >>>>> >>>>> Definitely I could replace BC550/BC560 with SOT-23 BC850/BC860 but it >>>>> doesn't make any sence because rest of the part is all big thruhole ones. >>>>> Nobody makes SMD polystyrene capacitors, less for high-tolerance ones. There >>>>> is no replacement for low-noise RN55/60 resistors (at least cheap one) for >>>>> sub-millivolt audio circuits. I would love to make SMD version but there is >>>>> no parts for that... >>>>> >>>> They won't go totally belly up by the only places I know that do >>>> thru-hole mass production are all in China now. So some day you may have >>>> to buy parts from Asia. >>> Nah, I don't do mass-production of those. There is no _THAT_ many people who >>> want to purchase a high-quality (not audiofool HiEnd one with inferior >>> parameters but enormous price tag) phono corrector :) My program is a couple >>> of thousands. And it is not just because of low demand but also because of >>> component availability. I'm using Russian Military Surplus/Spare Parts >>> Repository polystyrene capacitors, K71-1 with 0.5% tolerance and that is >>> limited and finite supply. Once they gone they gone forever. >>> >>> That product is hand-assembled so I don't care who does mass production :) >>> >>>> If your needs are audio check out the BCX70k. Nice low 1/f corner. >>> Thanks, but they are not any better than BC850/860. Roughly the same specs. >>> >>> BTW, I'd better go purchase a couple of reels of BC850C and BC860C while >>> they are available (from Mouser :)) before they gone... >>> >>> It is not BJTs that are so rare, it is JFETs... I would've been extremely >>> happy if 2SK369 existed in SOT-23... There is another problem though--I need >>> matched pairs of those :( Not something that can be done with Pick-and-Place >>> machine... >>> >>> There are Linear systems LSK389 but they are single source and not very >>> reliable one... One should be out of his mind to design something with such >>> a Maximese part... >>> >> The only dual FETs I am aware of (I mean that are left) are RF >> transistors. But it's MOSFETs. And even then you often down know how >> they track because most are multi-chip, meaning just two devices in one >> package, hoping that they come from the same area on the same wafer. >> Even then tracking won't be good. > > There is LSK389 dual monolythic JFET from Linear Systems that is supposed to > be a copy of Toshiba 2SK389 but they are not widely available. It is kinda > boutique part. And they did not copy the 2SK389 p-channel twin, 2SJ109 :( > > So for the current production (since not so long ago) the only ones are > single 2SK170/2SJ74 from Toshiba. They are TO-92 only... The better > n-channel one, 2SK369 (it has twice the Yfs of 2SK170) unfortunately is not > accompanied with a p-channel complement :( > You audio guys always want complement and stuff. "Yes, the appetizer was good. But the caviar was not Beluga." >>> As for the capacitors, Panasonic makes SMD polyphenylensulfide (hope I >>> spelled it right) ones that are supposedly on par with polypropylens but I >>> didn't try them yet. And the tolerance issue remains--they are 5%... >>> >> I've had that issue with 2x45 degree phase shifters in late 80s when >> helping another team. Had told them not to use direct conversion but ... >> >> Anyhow, we paid through the nose for 0.5% film caps. > > For quality audio one should only use polystyrene or at least polypropylene > capacitors so it is not just _film_ ones :) Russian surplus is not all that > expensive but it is not easy to get and the supply is finite; they don't > make them any more :( I'm paying something like $0.2-$0.35 when buying in > bulk through my russian buddies close to those military warehouses. > Well, that just the trick, Russian buddies :-) Back in the late 80s I had the minor Problem that the iron curtain hadn't fallen yet. Reagan asked Gorbachev a few times to knock it down but Gorbachev wasn't quite ready to get the sledgehammer out of the basement. An aggravating factor was that my knowledge of the Russian language consisted of the word na'sdarovje :-) So we had to live with whatever material we could get. And that sure wasn't much to write home about. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: John Larkin on 30 Jul 2010 10:47 On Fri, 30 Jul 2010 07:28:15 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Sergey Kubushyn wrote: >> Joerg <invalid(a)invalid.invalid> wrote: >>> Sergey Kubushyn wrote: >>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>> Sergey Kubushyn wrote: >>>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>>> Sergey Kubushyn wrote: >>>>>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>>>>> Sergey Kubushyn wrote: >>>>>>> [...] >>>>>>>>>> Just one example--I recently tried to buy several thousands of >>>>>>>>>> BC550/60C transistors. The funny thing was Avnet had BC560CTA @ $0.0163 >>>>>>>>>> each but no BC550C at all. I bought 2 ammopacks of 2,000 for $65 from them >>>>>>>>>> (that was all they had in stock.) On the other hand Arrow only had (and >>>>>>>>>> still have) BC550CTA at the same price but no BC560C at all. That was a >>>>>>>>>> couple of days ago. Now Avnet has 32K of BC550CTA in stock. If you were >>>>>>>>>> shopping at Avnet only a week ago you would've said that BC550C are >>>>>>>>>> unobtanium because they do not have them in stock while both findchips and >>>>>>>>>> octopart kept telling Arrow has plenty in stock. >>>>>>>>>> >>>>>>>>> Just what I said all along, should have gone to Digikey, they have >>>>>>>>> oodles of them: >>>>>>>>> >>>>>>>>> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=BC550CGOS-ND >>>>>>>> If you want to pay 3x the price, sure. And 7,055 pcs is not "oodles." And >>>>>>>> even those are just remnants, the other BC550Cxx are non-stocked. And this >>>>>>>> only one will also go non-stocked when they are bought. >>>>>>>> >>>>>>>> And they are exactly at the same point with BC560C. 4,000 left in stock at >>>>>>>> 2x price and a big fat warning they will go non-stocked once that inventory >>>>>>>> is sold. >>>>>>>> >>>>>>> Sergey, let's face it, nearly all thru-hole stuff is going to head for >>>>>>> lalaland. Ok, we were really early adopters over in Europe back then, >>>>>>> but since the start of my industrial career in 1986 I can't remember any >>>>>>> thru-hole board I have designed. And I've designed tons of boards. >>>>>>> >>>>>>> There will always be mfgs for thru-hole, just like Sovtek and Svetlana >>>>>>> do for tubes, but it's going to be boutique-ware. >>>>>> That is what I'm using them for. Not with tubes but for audio. >>>>>> >>>>>> The rumours about their death are grossly exagerrated. Fairchild makes those >>>>>> full steam and they are dirt cheap. Toshiba is back with their 2SK170 and >>>>>> 2SK369 parts that were discontinued long ago. And those parts are TO-92. >>>>>> BTW, Fairchild picked up a lot of Japanese transistors and now there is >>>>>> plenty of 2SA/SB/SC parts in their lineup. >>>>>> >>>>>> Definitely I could replace BC550/BC560 with SOT-23 BC850/BC860 but it >>>>>> doesn't make any sence because rest of the part is all big thruhole ones. >>>>>> Nobody makes SMD polystyrene capacitors, less for high-tolerance ones. There >>>>>> is no replacement for low-noise RN55/60 resistors (at least cheap one) for >>>>>> sub-millivolt audio circuits. I would love to make SMD version but there is >>>>>> no parts for that... >>>>>> >>>>> They won't go totally belly up by the only places I know that do >>>>> thru-hole mass production are all in China now. So some day you may have >>>>> to buy parts from Asia. >>>> Nah, I don't do mass-production of those. There is no _THAT_ many people who >>>> want to purchase a high-quality (not audiofool HiEnd one with inferior >>>> parameters but enormous price tag) phono corrector :) My program is a couple >>>> of thousands. And it is not just because of low demand but also because of >>>> component availability. I'm using Russian Military Surplus/Spare Parts >>>> Repository polystyrene capacitors, K71-1 with 0.5% tolerance and that is >>>> limited and finite supply. Once they gone they gone forever. >>>> >>>> That product is hand-assembled so I don't care who does mass production :) >>>> >>>>> If your needs are audio check out the BCX70k. Nice low 1/f corner. >>>> Thanks, but they are not any better than BC850/860. Roughly the same specs. >>>> >>>> BTW, I'd better go purchase a couple of reels of BC850C and BC860C while >>>> they are available (from Mouser :)) before they gone... >>>> >>>> It is not BJTs that are so rare, it is JFETs... I would've been extremely >>>> happy if 2SK369 existed in SOT-23... There is another problem though--I need >>>> matched pairs of those :( Not something that can be done with Pick-and-Place >>>> machine... >>>> >>>> There are Linear systems LSK389 but they are single source and not very >>>> reliable one... One should be out of his mind to design something with such >>>> a Maximese part... >>>> >>> The only dual FETs I am aware of (I mean that are left) are RF >>> transistors. But it's MOSFETs. And even then you often down know how >>> they track because most are multi-chip, meaning just two devices in one >>> package, hoping that they come from the same area on the same wafer. >>> Even then tracking won't be good. >> >> There is LSK389 dual monolythic JFET from Linear Systems that is supposed to >> be a copy of Toshiba 2SK389 but they are not widely available. It is kinda >> boutique part. And they did not copy the 2SK389 p-channel twin, 2SJ109 :( >> >> So for the current production (since not so long ago) the only ones are >> single 2SK170/2SJ74 from Toshiba. They are TO-92 only... The better >> n-channel one, 2SK369 (it has twice the Yfs of 2SK170) unfortunately is not >> accompanied with a p-channel complement :( >> > >You audio guys always want complement and stuff. "Yes, the appetizer was >good. But the caviar was not Beluga." > > >>>> As for the capacitors, Panasonic makes SMD polyphenylensulfide (hope I >>>> spelled it right) ones that are supposedly on par with polypropylens but I >>>> didn't try them yet. And the tolerance issue remains--they are 5%... >>>> >>> I've had that issue with 2x45 degree phase shifters in late 80s when >>> helping another team. Had told them not to use direct conversion but ... >>> >>> Anyhow, we paid through the nose for 0.5% film caps. >> >> For quality audio one should only use polystyrene or at least polypropylene >> capacitors so it is not just _film_ ones :) Russian surplus is not all that >> expensive but it is not easy to get and the supply is finite; they don't >> make them any more :( I'm paying something like $0.2-$0.35 when buying in >> bulk through my russian buddies close to those military warehouses. >> > >Well, that just the trick, Russian buddies :-) > >Back in the late 80s I had the minor Problem that the iron curtain >hadn't fallen yet. Reagan asked Gorbachev a few times to knock it down >but Gorbachev wasn't quite ready to get the sledgehammer out of the >basement. An aggravating factor was that my knowledge of the Russian >language consisted of the word na'sdarovje :-) > >So we had to live with whatever material we could get. And that sure >wasn't much to write home about. I spent six weeks working in Moscow, in the Breshnev days. I learned four words spa-seeba thank you dos-ve-don-ya bye milinki tiny (as in "tiny capitalist) klooch tool of some/any sort It was interesting. John
From: Joerg on 30 Jul 2010 11:58 Spehro Pefhany wrote: > On Thu, 29 Jul 2010 14:11:22 -0700, the renowned Joerg > <invalid(a)invalid.invalid> wrote: > >> Spehro Pefhany wrote: >>> On Thu, 29 Jul 2010 07:30:03 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> Sergey Kubushyn wrote: >>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>> Sergey Kubushyn wrote: >>>>>>> Joerg <invalid(a)invalid.invalid> wrote: >>>>>>>> Sergey Kubushyn wrote: >>>>>>>>> Tim Williams <tmoranwms(a)charter.net> wrote: >>>>>>>>>> "Martin Riddle" <martin_rid(a)verizon.net> wrote in message news:i2ntnv$o1h$1(a)news.eternal-september.org... >>>>>>>>>>> Maybe they don't like paying 3x the price for those parts? >>>>>>>>>> I don't know about that, I've shopped around and it's no worse than a factor of 2, with most of them being on par or better. >>>>>>>>> As a matter of fact Mouser is not _THAT_ bad. It is almost on par with >>>>>>>>> Arrow/Avnet/etc. Sometimes even cheaper. And in most cases their markup is >>>>>>>>> less than 100%. >>>>>>>>> >>>>>>>>> That is another twin, DigiKey, that has everything marked up to the ears. I >>>>>>>>> never understood why people do purchase anything from them... >>>>>>>>> >>>>>>>> Because they have the only search engine that works. >>>>>>> Do they? >>>>>> Oh yeah. None of the others comes even close. And they know it. >>>>>> >>>>>>> >>>>>>> And another question -- even if they were so unique why would one start >>>>>>> searching anything on DigiKey (or whatever be it Mouser/Allied/Arrow/etc?) >>>>>>> >>>>>> As I said, because I find stuff the fastest on Digikey. My clients have >>>>>> to pay for my time on their projects and on their behalf I need to be >>>>>> frugal with billed hours. Even if the parts for 2-3 prototypes end up >>>>>> costing five bucks more that's peanuts compared to the frustrating extra >>>>>> half hour on one of the other sites. >>>>>> >>>>>> >>>>>>> It is much wiser to start with something like findchips.com or Octopart that >>>>>>> would search _MULTIPLE_ sites for you and then you could choose which one to >>>>>>> use... Octopart even has a FireFox plugin that installs alongside with >>>>>>> Google and friends. >>>>>>> >>>>>> That only works if you already know what you want, down to the part >>>>>> number. I often must peruse the selection, see what's there, high in >>>>> Have you ever tried? You don't need a part number to search for e.g. "0.1uF >>>>> Polypropylene Capacitor." That works on both findchips and octopart. And >>>>> they show you what's in the inventory of major distributors. Including >>>>> DigiKey :) >>>>> >>>> Ok then, go on Findchips, key in this: >>>> >>>> 0.1uF ceramic >>>> >>>> Then you know what I mean. According to the results most distributors >>>> don't carry any. I guess that takes the cake. >>> Well, it is called findchips. You have to go to findcaps.com for >>> capacitors. >>> >> The first category on there was "umbrellas". Hmmm ... :-) >> >> >>> I like the hack that allows you to sort by price on Digikey (using >>> Greasemonkey). Shame they don't incorporate it themselves. >>> >> Hack? Where? Where? <pant ... pant> > > I use this with Firefox. > > Note that it has to load the pages first, so if you have scores of > pages it might take a moment or two each time you search, even with a > fast internet connection, but all-in-all it's a good thing. I > generally leave it turned on all the time. > > http://students.washington.edu/acleone/codes/greasemonkey/digikey_sort_by_price/ > Thanks! Very intersting. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 30 Jul 2010 12:07
John Larkin wrote: > On Fri, 30 Jul 2010 07:28:15 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > >> Sergey Kubushyn wrote: >>> Joerg <invalid(a)invalid.invalid> wrote: [...] >>>> Anyhow, we paid through the nose for 0.5% film caps. >>> For quality audio one should only use polystyrene or at least polypropylene >>> capacitors so it is not just _film_ ones :) Russian surplus is not all that >>> expensive but it is not easy to get and the supply is finite; they don't >>> make them any more :( I'm paying something like $0.2-$0.35 when buying in >>> bulk through my russian buddies close to those military warehouses. >>> >> Well, that just the trick, Russian buddies :-) >> >> Back in the late 80s I had the minor Problem that the iron curtain >> hadn't fallen yet. Reagan asked Gorbachev a few times to knock it down >> but Gorbachev wasn't quite ready to get the sledgehammer out of the >> basement. An aggravating factor was that my knowledge of the Russian >> language consisted of the word na'sdarovje :-) >> >> So we had to live with whatever material we could get. And that sure >> wasn't much to write home about. > > I spent six weeks working in Moscow, in the Breshnev days. I learned > four words > > spa-seeba thank you > > dos-ve-don-ya bye > > milinki tiny (as in "tiny capitalist) > > klooch tool of some/any sort > Does the last one sound like "kludge"? Most of the Russian we heard in Germany was from returning POWs. Stuff like "dawai" (quick, let's get moving here!), "raboti" (work), "Rasberaitje pa piat" (line up in rows of five). Some of it made it into the language just like "cool" did, or "angst" over here. > It was interesting. > According to Russian engineers I've worked with it is a country with a very deep cultural history, not just the well-known stuff such as the Bolshoi theatre or the choirs. Unfortunately now very messed up by organized crime and politicians, at least that's what they told me. If you want to design stuff or start a business with any chance of an ROI you have to leave :-( -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |