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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Chuck Harris
Can you say "Strawman argument?"
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-Chuck Harris M Yachad wrote: Chuck |
Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Chuck
¡°You didn't listen to what I said about the electrolyte.¡± On the contrary, I ¡°listened¡± and paid close attention. I even quoted each part of your message, and commented on it in detail. In the West, I understand that the cultural term ¡°to listen to somebody¡± sometimes means to hear them, to pay attention, then to AGREE with them, and to DO as they say. Here, culturally, ¡°to listen¡± means to pay attention only. There is NO obligation whatsoever to agree with the speaker, or to do as he says. So I have definitely listened to you, paid attention to you, but I am under no obligation to agree with you, even if you put forward what on the face of it, is a convincing argument, but is lacking in substance, proof and facts. ¡°The corrosive, to copper, electrolyte in 105C capacitors makes a mess out of copper, but does nothing to aluminum and aluminum oxide. An electrolyte can be corrosive to one material, and totally benign to another.¡± Chemistry 101. No argument at all. Chemicon¡¯s problem was the electrolyte destroying the capacitors from within, causing widespread shorts. The copper traces of the PCB¡¯s were unaffected. That modern failure is highly relevant to our discussion. Furthermore, that shocked the EE community, because Chemicon is one of the most reliable manufacturer's out there, and was generally trusted to do their homework, so that crap like that shouldn't happen. The 90¡¯s failure of counterfeit electrolyte (Chinese manufacturers) is well-known, and may or may not have caused shorts when venting ¨C however there is not sufficient absolutely empirical evidence backed up with any manufacturer's data, to make a general claim. ¡°When you operate a modern electrolytic capacitor on lower than its nominal voltage rating, it is not harmed, and it does not change in any way.¡± That¡¯s appears to be a convincing claim, but unless you can support that with absolute proof across all manufacturers, I cannot accept that. Chemicon¡¯s case refutes your assumption in its entirety. ¡°Today's 25V capacitor is yesterdays 50V capacitor.¡± Can you offer any proof for that claim? ¡°If the electrolyte was as corrosive as you imagine, my bags of NOS capacitors would have all eaten away their aluminum oxide dielectric and all be short circuit. They are not. They are as good as the day they were made. Electrolytic capacitors from 40-50 years ago would be long gone in similar circumstances.¡± I do not accept your supposition. You have a fact on the ground, and you have chosen a very convenient reasoning to ¡°support¡± the fact, but you know as well as I, that there is no proven relationship between the apparently "good" condition of your capacitors and the propensity of a given electrolyte to corrode under a working voltage load. Have you checked Dissipation, tangent and impedance of each capacitor against the manufacturer's data? Have you run the capacitor at the extreme temperature limits specified, and then rechecked the performance? Until you have that substantial empirical data, your claim is unsubstantiated. ¡°You are limiting your choices based on imagined problems.¡± That¡¯s your conclusion, not mine. I have spent many years in a sensitive manufacturing environment under tight tolerances, and engineers were "encouraged" to research their proposals to be watertight if they wanted them to be considered for inclusion in production. Instead of hampering and discouraging suggestions, that policy caused excellence in the extreme. -Chuck Harris ¡°OBTW, Nichicon of 1975 is a far different company from Nichicon of 2018. Dare we compare Tektronix of 1965 to the Tektronix of today? Neither company has any of the original founders, nor their instincts for quality, involved today.¡± Would you like to stand up in court and defend that statement against Nichicon¡¯s lawyers? I doubt it. Tek, I¡¯ll agree with you. But using Tek's decline to stretch your reasoning to apply to Nichicon as well, is pushing your confidence into a very dangerous zone. In short, you haven¡¯t provided me with any empirical statistically relevant proof that I should change my conservative habits. I¡¯ll leave you with one thought. In light of your proposal to use massively overrated capacitors in all applications, then in these days of excessive cost-cutting and profiteering, one may propose to Nichicon¡¯s management: Produce only capacitors rated at 35V (smallest physical size 5mmx11mm), 63V (8mmx15mm) 100V (10mmx20mm). What a fantastic savings in production costs! Why have no capacitor manufacturers streamlined production like that? The profit potential must be enormous. AND the BoM of appliance manufacturers would be vastly simplified. More profits. No, I suggest to you that there are things that we don¡¯t always know about, in spite of your best intentions, and walking the tried and true path is the honest way to deliver best value to my customers. There are reasons and considerations we don¡¯t even know about, and even if failures occur, nobody is going to admit responsibility. This discussion has been stimulating, however, I remain unconvinced, and I will continue to use capacitors correctly matched to actual circuit voltage. Any other users who choose to go overboard and install a 330uF 160V cap in a place where a 25V cap is required, is not only wasting his hard-earned money substantially, but may discover at some future point in time that the circuit becomes unstable. Or, he may not. I¡¯ll leave it up to users who choose those highly overrated caps, to post their experience in a few years. I¡¯m not holding my breath. Menahem |
Re: Repairing plated through holes.
Tektronix used eyelets/rivets on their first PCBs and abandoned the practice
because of failures. I think the mechanism is a difference in thermal expansion that eventually cracks the soldering. I repair JVC TT-101 turntables from the 80's. They used eyelets/rivets on a two sided unplated board. My standard repair practice is simply to resolder every eyelet/rivet and then test it and that always fixes them. I have no more information on the failure mechanism. I do my plated through hole repairs simply with 30 gauge wire through the hole and soldered on both the top and bottom. I also have to do this on unplated boards when adding a socket as the original required soldering on both the top and bottom. Dave |
Re: Repairing plated through holes.
Delco used the 'griplet' in one or two model years. They were a disaster. They sent out a service bulletin, and paid a set price to repair those AM/FM radios. They were plated steel, so you had to run wires through them.
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I have some of the Pace eyelets out in my shop, but the roof lead in the parts room, and the floor was particleboard, covered with old carpet so the shelving went through the floor and stuff went everywhere. A local vocational school used the Pace system, and a kit of materials were issued to each new student. The teacher gave me the leftovers from kids who dropped the course. Michael A. Terrell -----Original Message-----
From: Glenn Little <glennmaillist@...> |
Re: Repairing plated through holes.
On Sat, 16 Jun 2018 17:46:28 +0200, you wrote:
You can still buy the pop rivet nuts, but much more $$ than that.It will, but the friction on the threads is likely to strip them if you don't use a screw long enough to fully engage the nut. I'd also worry about torque spinning the thing. You should be able to find the tools on ali-baba, or the local equivalent. Harvey
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Re: Repairing plated through holes.
I had two sizes, one for 6-32 that used the small hole. the other was for 10-32, and it used the large hole. they were just a smooth, hardened steel shank, with just enough threads at one end to reach the bottom of the Rivnut. I got the small one in the boxes of 100, and the large one was in a retail pack of 25.
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<> This page shows how to do it with a bolt, two washers and two nuts. One nut is oversized, and is just a spacer. I would use the right size of drill stop, and that would eliminate the large nut and one washer. They were over $10.00 a box, but that surplus dealer had over 1000 boxes that were likely bought by the pound like the other hardware. there were 100 boxes per case, and I should have bought a case, instead of four boxes. Michael A. Terrell -----Original Message-----
From: stefan_trethan <stefan_trethan@...> |
Re: Repairing plated through holes.
On Sat, 16 Jun 2018 11:40:15 -0400 (GMT-04:00), you wrote:
They also made the rivnut,which is an internally threaded version of a pop rivet that used an adapter to set with a pop rivet tool. I used them in some projects. I wished that I had boght more of them, surplus. They were 50 cents/100 in USM boxes.Harbor freight has them, aluminum, of course. Amazon seems to have tons of them, but not at 50 cents/100, sadly. Harvey
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Re: S6 Sampling Head Bridge Cavity Question
If I look back on my life it has been filled with similar behavior. There areOh but you are definitely not alone on that ;-) I had a good laugh when I saw which (apart from the time axis scaling) seemed awfully familiar ... Cheers Peter |
Re: Repairing plated through holes.
Mouser stocks several sizes of staking tools from Keystone that might come in handy. Not really cheap, but I have one of the sets (don't remember which one) that I use when I need to stake a terminal onto a PCB. Keystone part nos TL-20, TL-21 and TL-22. These are made primarily for staking turret terminals onto a PCB, but also work well with larfer eyelets and rivets.
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Cheers, Dave M On Sat, Jun 16, 2018 at 04:48 am, lop pol wrote:
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Lots of parts leads to confusion, its all good. Once this is done it will be good for a year or two at least.
Here is another correction C1113 180 ?F 40 ELCTLT 330 ?F 50 C1114 250 ?F 100 ELCTLT 330 ?F 50 Should be... C1113 180 ?F 100 ELCTLT 330 ?F 160 C1114 250 ?F 100 ELCTLT 330 ?F 160 To the A5 listing please add: C2010 33 ?f 10 ELCTLT 33 ?F 10 I have not looked at the A1 board yet, but I will let you know if I find anything there |
Re: Tek 2337 (looks mint) on Goodwill.
Looks like it is very clean, If I still lived in Ft worth I'd run over and turn it on to check it out. has probes and all.
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100MHz Analog Scope ( later 150MHz version I think) plus a built in DMM More info over on Tekwiki Godwill in the auction business ..who knew -DC manuals@... On 6/16/2018 11:47 AM, David Berlind wrote:
I'm sure everyone here has seen one of these. But I haven't. Is it some sort of hack of a digital scope? It looks mint (and cool). --
Dave Manuals@... www.ArtekManuals.com |
Re: Repairing plated through holes.
Pace made a "fused eyelet setter" .
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This was an eyelet staking tool that ran high current, low voltage through the eyelet after the eyelet was staked and while the eyelet was still under compression. This fused the flared part of the eyelet to the lands. Motorola used eyeletted boards in some of their two way radios. This was the major source of failure as the eyelet solder connection broke free of the lands. The fix for this was to resolder all of the eyeletted connections on both the top and bottom of the board. One source of PCB repair things is Glenn On 6/15/2018 10:28 PM, lop pol via Groups.Io wrote:
I would like to affordably put together the things needed to repair plated through holes. Anyone have any thoughts? I'm asking because I dont want to buy this more than onct setter"e. My pocket has not much room for mistakes right now and i seem to do a lot better asking here before buying. Thanks guys --
----------------------------------------------------------------------- Glenn Little ARRL Technical Specialist QCWA LM 28417 Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178 QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR "It is not the class of license that the Amateur holds but the class of the Amateur that holds the license" |
Re: Repairing plated through holes.
stefan_trethan
You can still buy the pop rivet nuts, but much more $$ than that.
You said they use an adapter, I have never seen that. Around here you need to buy a dedicated rivet nut tool for around $100 (which looks much like a slightly modified $20 pop rivet tool). I always speculated that they are set just like a pop rivet, but with a threaded rod instead of the discardable metal shank in a regular rivet. My plan was, should I ever need to set a rivet nut, that I would take a hard screw and put that in the rivet, and pull on the screw from the outside with a washer and a nut. Do you have any opinion if that plan might succeed? I have been curious about it for years. ST On Sat, Jun 16, 2018 at 5:40 PM, Michael A. Terrell <mike.terrell@...> wrote: They also made the rivnut,which is an internally threaded version of a pop rivet that used an adapter to set with a pop rivet tool. I used them in some projects. I wished that I had boght more of them, surplus. They were 50 cents/100 in USM boxes. |
Re: Repairing plated through holes.
They also made the rivnut,which is an internally threaded version of a pop rivet that used an adapter to set with a pop rivet tool. I used them in some projects. I wished that I had boght more of them, surplus. They were 50 cents/100 in USM boxes.
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Michael A. Terrell -----Original Message-----
From: "ebrucehunter via Groups.Io" <Brucekareen@...> |
Re: Repairing plated through holes.
The key is the eyelet technique only works with two layer boards. The art
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techniques for rebuilding through holes and multi-layer boards but it's not something you do yourself although I tried it a couple times by building my own Electrolux replating set up. On Fri, Jun 15, 2018, 10:38 PM Harvey White <madyn@...> wrote:
On Fri, 15 Jun 2018 20:33:52 -0700, you wrote:On Fri, Jun 15, 2018 at 08:17 pm, Mark Goldberg wrote:or |
Re: Repairing plated through holes.
About 50 years ago I purchased an eyelet press from Kepco, a company that then sold printed circuit board materials. At the time they offered a variety of different diameter rivets, of different lengths, and in both copper and brass. The press came with a number of special tips needed for the different size rivets. I was later able to fabricate special tips to also set Vector, rivet-type terminals.
Unfortunately, as a previous contributor has remarked, these eyelets almost always eventually gave trouble if not carefully soldered to the foil on both sides. Even soldered eyelets sometimes gave trouble, probably because, as another has mentioned, you need a little space under the head for solder to properly flow. In looking at the press, I saw something I had never noticed before. The press was made in Italy by United Shoe Machinery, the company that made eyeletting machinery for the shoe industry and the original developer of the pop-rivet. Bruce, KG6OJI |
Re: Flyke 3330b
No coffee yet this morning, I missed one of the 3s :-)
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Paul On Sat, Jun 16, 2018 at 10:27:42AM -0400, Artekmedia wrote:
Paul --
Paul Amaranth, GCIH | Rochester MI, USA Aurora Group, Inc. | Security, Systems & Software paul@... | Unix & Windows |
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