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Re: Different view of the 465M, etc. --where to find parts
Well, Walter, that's the nice thing about this world. Everybody's
different (especially those who think that hp made the best scopes, although I did much prefer their 130C over the Tek 503) and that makes for a lack of boredom. I still prefer the original 465 or 475 over the 465M. Now, if you want to discuss the queen bitch of the Tek portables, turn to the 434, <B500000. Every mechanical engineer on that project should have been summarily fired and sent to work for Hewlett-Packard. But that's another story. By the way, the 465M didn't have a fan, as I recall, likely part of the specifications but just as likely a cost-savings effort by Tek whose employee profit share had already bottomed out when that scope hit the market. And the modularization was so that they could sell the scope to the Army and Air Force who had their troopies so trained on echelon step repair that the poor folks could only fix things by swapping out entire modules rather than doing component level repair. ;>) But that's also another story. And it WAS more expensive to purchase. WHY? It cost so much less to build. I don't understand. I'm not trying to be argumentative, but the 465M HAD to be easier to repair, because on a per capita basis, a larger percentage of them failed. It was to the point that I was personally wondering if the FAA had added a rider to their procurement contract, "A minimum of 10% of all units must arrive defective." Since the depot was in OKC, I got all the FAA's failed warranty 465Ms (and all of their failed 1502s, no matter their status), so ended up getting a bad taste in my mouth. Just because you have a different opinion doesn't mean that you aren't right. You've obviously had a much nicer experience with them that I did, and that's great. I liked the T900s while a lot of folks thought they were junk. I've met old TV repairmen who would take a Telequipment over anything else. You just never know. Dean |
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Different view of the 465M, etc. --where to find parts
Everybody seems to have missed the entire point of the 465M, it was
designed specifically for a MTTR of 30 minutes, and the modular design makes that possible. The MTTR of a regular 465 is measured in days sometimes. It is hardly an inferior version of the 465, but really a model with the same functionality, but designed to be easier to service. The case opens quickly with a coin, and the scope quickly breaks into three major subassemblies, all easily probed and repaired. Hardly a step backwards. The military asked for this level of repair capability, and got it. having worked on every variation and age of the 465/475 family, I like the 465M the best, as it is far easier to trouble shoot and fix. the modules are a real delight if you have spares, and make some complex problems much easier to fix and isolate. like every module connector in history, they need to be cleaned, and MAINLY go bad because people failed to screw the modules back in correctly, and "made metal" by vibration within the mating connector. I have seen many with half the internal hardware parts missing, thanks to previous technicians. the 465 (no suffix) is (by contrast) a virtual pretzel of mechanical design, and very, very difficult to work on or repair. all versions function pretty well, but I never buy the no suffux version any more, as they all have the same problems, (dry caps, switch problems, etc.) due to old age. B's are very nice, especially high serial numbers, but are still built for people with lots of time on their hands. The 465 is a landmakrk design, and virtually all scopes by all makers after them derive their ergonomics and control functions from the 465 concepts. Tek even published their book series about the same time (69-71), spelling out how to design the key elements of a high performance scope from the 465 to the 7000 series. No doubt they regretted that, since every competitor quickly leared all their deepest secrets, and the books were soon withdrawn. if you see a set, grab them, they are the best books ever written on CRT and scope design. The T900 series was far different from other Tek products, and a vastly upgraded product for Telequipment to sell in the UK, their eventual european subsidiary. that corporate acquisition (Telequipment already existed in the UK as a scope maker) was to allow market access to the common market in europe, but clearly did not go so well. The original Telequipment products were garbage, of incredibly low workmanship standards, and marginal design throughout. The T900 series was a way of rectifying that problem by providing a better product base for Telequipment to sell and manufacture, along with other Tek products. The only common item between the T900 series and the 465M is the blue plastic material used in the case, there is no other relationship. People who think they have deeper internal commonality are directed to the manuals, it is quite clear they are totally unrelated products. On another note, For those deep into Tek restoration, we have many Tek CRTs, semis, pots and transformers on our site, along with lots of cross-ref data. more bits are getting added regularly, and we hope to have a new section with trim, case parts, CRT filters and knobs up soon. Our spares are mainly for later solid state scopes, and other than CRTs and some tubes, we do not have too much for the 531/545/561 models. walter shawlee sphere research |
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Re: 465M Flaky vertical height.
Miroslav Pokorni
As much as I like sockets, I must agree with Dean. It is sure handy to be
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able to remove and replace components easily, but that should be confined to prototyping. The first Tektronix scope that I repaired, and that was the first ever broken Tektronix that I saw, was a 422 with one transistor lead being clear out of socket, two other leads bent. One could argue that lead pulling happened during disassembly, but that was the only fault with the scope, fixing pulled transistor fixed the scope. Arguing that socket had a bad contact to start with and disassembly dislodged transistor in bad socket would be a big stretch. The 422s were small portable scopes banged around by service people and it must have been shock in handling and transport that pulled transistor lead. Failure that I described is quite rare in occurrence, but is a kind of 2X4 to use against sockets. I was at a test conference in early 80s and one of speakers stated: ' there is no place for a socket in modern electronics board'. He was referring to both, an inability to test socketed components on a bed-of-nails tester and intermittent faults caused by sockets. To my mind, using a low contact pressure socket (the most common type of socket) in a production unit is begging for trouble. Regards Miroslav Pokorni -----Original Message-----
From: dhuster@... [mailto:dhuster@...] Sent: Wednesday, August 08, 2001 7:39 AM To: TekScopes@... Subject: [TekScopes] Re: 465M Flaky vertical height. I'm not sure I've figured out how to reply on this forum yet. I'd replied previously to the #445 OP as I am now "465M Flaky vertical height" figuring that it would end up in the queue at the end, but somewhere, the reply got lost. It had to do with "is the 465M better thean the 465?". I'll try again. Phil, the T900's look nothing like any TQ scope. The T900-series is a Beaverton development and TQ is completely European, and never do the two meet. Like Stan, I never remember the Tek name or logo ever appearing on a TQ product. Someone mentioned a TQ that they used that had a horizontal layout. I think that was the D75, but I remember the CRT in the center, vertical on the left, horizontal on the right, but that's been a long time ago .... I think that there was a CRT-over-electronics version of the D75 ... maybe D85? I can't remember. But these were plug-in scopes for which there were only the one plug-in that I know of for each side. I did an April Fools Day Marketing Sales Release when I was in the Dallas Service Center that said that TQ was coming out with a sampling system plug-in for that scope, selling for $1500 or some such, and was unusual in that it had TV trigger. One sales engineer took it hook, line and sinker. I still have a copy of that thing somewhere. The entire T900-series product line: T921: single channel, single timebase, 15 MHz T922: dual channel, single timebase, 15 MHz T922R: rack-mounted T922 T912: dual channel, bistable storage, 10 MHz T932: dual channel, single timebase, 35 MHz T935/A: dual channel, dual timebase, 35 MHz As I recall, the T900-series was introduced in late 1975, early 1976. The T921 was used as the primary illustration in the original "Basic Oscilloscope Operation" (1978), AX-3725-1 The T922 and T935A were also shown in cameo appearances. Stan, in the field, transistor sockets were some of the handiest things for us service technicians. Suspect a bad transistor? Just pluck it out, pop it in the curve tracer and check it. I think that's where you're coming from when you lamented the lack of such sockets in the T900-series (the TQ stuff had sockets). However, transistor and IC sockets were the one greatest source of warranty work, repairs and intermittents in the field. When Tek got rid of the sockets (RAM and expensive ICs still had sockets) and most of the ribbon cable connectors, intermittents plummeted. At the bench, you might have a dead circuit. You'd pluck out a transistor, check it, it was good, put the transistor back, the scope started working. An intermittent. So, you had to replace the socket AND the transistor to insure that you weren't going to be sending an intermittent back out in the field. Sockets didn't save Tek any money. It cost more to buy and install them and it cost more on the repairs and callbacks. I believe that the 455, T900-series, TM500-series and the 5000-series and later the 465M were the first Tek products to not use sockets. It looks like later posts already mentioned the reasons for the 465M coming into existance, the pre-existance of the 455, the fact that the 455 is a T900 in lineage, etc. Dean ------------------------ Yahoo! Groups Sponsor To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to |
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Re: 7B70 gone bad...
John, with no manual, it's difficult. Since intermittents are a big
problem with Tek products having socketed component, the first thing I'd do is rock every transistor around in its socket. Better yet, pluck the transistor out and push it back in a couple of times. Do the same with the TDs and any ICs. That may clear the problem up. Dean |
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Re: 465M Flaky vertical height.
I'm not sure I've figured out how to reply on this forum yet. I'd
replied previously to the #445 OP as I am now "465M Flaky vertical height" figuring that it would end up in the queue at the end, but somewhere, the reply got lost. It had to do with "is the 465M better thean the 465?". I'll try again. Phil, the T900's look nothing like any TQ scope. The T900-series is a Beaverton development and TQ is completely European, and never do the two meet. Like Stan, I never remember the Tek name or logo ever appearing on a TQ product. Someone mentioned a TQ that they used that had a horizontal layout. I think that was the D75, but I remember the CRT in the center, vertical on the left, horizontal on the right, but that's been a long time ago .... I think that there was a CRT-over-electronics version of the D75 ... maybe D85? I can't remember. But these were plug-in scopes for which there were only the one plug-in that I know of for each side. I did an April Fools Day Marketing Sales Release when I was in the Dallas Service Center that said that TQ was coming out with a sampling system plug-in for that scope, selling for $1500 or some such, and was unusual in that it had TV trigger. One sales engineer took it hook, line and sinker. I still have a copy of that thing somewhere. The entire T900-series product line: T921: single channel, single timebase, 15 MHz T922: dual channel, single timebase, 15 MHz T922R: rack-mounted T922 T912: dual channel, bistable storage, 10 MHz T932: dual channel, single timebase, 35 MHz T935/A: dual channel, dual timebase, 35 MHz As I recall, the T900-series was introduced in late 1975, early 1976. The T921 was used as the primary illustration in the original "Basic Oscilloscope Operation" (1978), AX-3725-1 The T922 and T935A were also shown in cameo appearances. Stan, in the field, transistor sockets were some of the handiest things for us service technicians. Suspect a bad transistor? Just pluck it out, pop it in the curve tracer and check it. I think that's where you're coming from when you lamented the lack of such sockets in the T900-series (the TQ stuff had sockets). However, transistor and IC sockets were the one greatest source of warranty work, repairs and intermittents in the field. When Tek got rid of the sockets (RAM and expensive ICs still had sockets) and most of the ribbon cable connectors, intermittents plummeted. At the bench, you might have a dead circuit. You'd pluck out a transistor, check it, it was good, put the transistor back, the scope started working. An intermittent. So, you had to replace the socket AND the transistor to insure that you weren't going to be sending an intermittent back out in the field. Sockets didn't save Tek any money. It cost more to buy and install them and it cost more on the repairs and callbacks. I believe that the 455, T900-series, TM500-series and the 5000-series and later the 465M were the first Tek products to not use sockets. It looks like later posts already mentioned the reasons for the 465M coming into existance, the pre-existance of the 455, the fact that the 455 is a T900 in lineage, etc. Dean |
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Re: 465M Flaky vertical height.
Stan or Patricia Griffiths
donlcramer@... wrote:
Fascinating!It could have been a cost issue, but it was not a "price" issue. In the 1978 Tek catalog, for example, you see the 465 at $2295 and the 465M at $2345, or $50 MORE. In spite of the higher price, I suspect the 465M was cheaper to build than the 465 and certainly an inferior instrument to the 465. (That's just my opinion, folks. There are differing opinions, I am sure.) The 465M did meet a mil spec that was not advertised for the 465 and it was completely provisioned through the U.S. Goverment Supply Depots. The 455 was in the Tek Catalog before the 465M was and I suspect that it was found that the normal 455 made much more than its advertised 50 MHz bandwidth. With just a little engineering effort, it could be upgraded to 100 MHz and then it would qualify for some large government procurements. I don't have the inside story from the "horse's mouth", but I would bet money on what I have related here. Makes sense to me knowing how Tek operated in those years . . . Stan w7ni@... |
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Re: 465M Flaky vertical height.
Stan or Patricia Griffiths
Phil (VA3UX) wrote:
At 03:40 PM 8/6/2001 -0600, you wrote:Well, I concur with all of the above, except the following. I don't ever rememberI always wondered what happened to Telequipment.That's what happened Doug. Tek bought Telequipment in late 1966 in order the "Tek" name appearing on any Telequipment scope. The T900 series was a separate engineering effort based in Beaverton, OR and had nothing whatsoever to do with Telequipment, as far as I know. It was a low-cost effort and that is where the similarity to Telequipment ends, to the best of my recollection. What really happened to Telequipment is that a decision was made by Tek management to shut it down because customer satisfaction with the products was just too low. What was saved in the cost of initial purchase was quickly spent in maintenance of Telequipment scopes. When you save the cost of transistor sockets, for example, you have to spend more to replace the transistor when it does go bad. The long term economics of buying a low-cost scope is just not a good concept, in general, especially for commercial customers. Stan w7ni@... |
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Re: T900 photo
Doug Hale
Don,
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Thanks for the picture and descriptions. This is not the scope I used. The one I used had the Telequipment name on it. It was horizontally layed out. The tube was on the left, then the vertical section with the horizontal on the right, but that was so long ago. After college I worked as a technician for HP. And we, of coarse, used HP scopes. Man, I hated those things. These were the 180 series mainframes with plug-ins. Triggering just was not stable. You had to have one hand on the probe and one on the trigger knob to see anything. At a following job, I used both Tek 7704s and HP 1740 ???. I'd go to great lengths not to have to use the HP. That reminds me of a story. At the job mentioned above, in about 1979 I designed a video lookup table in 10K ecl. It ran at about 17.5 ns. With over 450 ICs on one card, it went though quite a thermal cycle powering up and down. The prototype PC cards were over-etched and the traces would pull away from the pads from the thermal cycling. So I'm in the lab with the scope and every 15 minutes the VP runs in and sayes "how's it goin', when can I ship it?". After a couple of hours of this, I've gotten maybe a halve an hours work done. He runs into the lab again and I just stand up and hand him the scope probe and run off to the rest room. When I come back I get a good couple of hours of uninterrupted work in and the board is ready to ship. Doug donlcramer@... wrote: Hi Doug, |
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Re: T900 photo
Hi Doug,
There is a photo of a T912 on ebay at: The style is similar on all the T900 scopes. Blue plastic case, tube to upper right and controls at left and below. My foggy memory says the T912 was the lowest cost one in the line and was a single channel, therefore I wonder if the scope pictured is actually a T922. This is a question I bet Stan could clear up in a heartbeat. I'm getting out on a limb here but I recollect the T92x was a 20MHz scope and the T935 was the top of the line at 35MHz, dual channel and might have had delayed sweep, too. There was also a storage scope in the middle there somewhere (10MHz BW?). T900 was definitely a Beaverton product. Look close and you can see components similar to the other scopes. After my stint in DSI/portable scopes, I moved to Tek Labs where I came across both early production and also some engineering boards for the T935. That was in Bldg 50, so I assume that the scope line was either designed in 50 or perhaps the eval team which followed it was in 50. I almost had enough parts scrounged to build one but with the impatience of youth, I gave them away to another Tek employee. I'm not sure whether he ever got it all together.... Telequipment was an entity unto themselves as far as the product line was concerned, not having any connection with Beaverton in design or parts sourcing. We had a bunch of them at the local community college and they were ok, but no Tek 500 series, which we also had access to. For trivia buffs out there, a Telequipment scope features prominently in the cockpit of the Zero-X spacecraft in Gerry and Sylvia Anderson's "Thunderbirds are Go" movie, which was British made. Don |
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7B70 gone bad...
john graves
I've followed this group for quite a while: what an incredible wealth of knowledge the contributors have! Following this has been very educational for me.
I now have my first request for help: Recently I purchased three 7B70 timebases on E-bay. The best one of the group had been working perfectly until recently, but it suddenly went bad. The symptom is that it will only sweep once, then the trace freezes on the rightmost of the CRT. Any vertical excursions still occur, but the trace just sits there. This happens on any triggering mode setting. I do not have a manual for this timebase, but since I have two others that more-or-less work, I think that I could swap out the defective component. I just need some better idea of which component may be defective. If someone could suggest which reference designation would lead me to a likely bad part, then I'll un-plug and plug away. Thanks so much for any help! ---John Graves |
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Re: 465M Flaky vertical height.
Miroslav Pokorni
Thank you, Phil; it is only now when I saw your writing that I remembered
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that 'Tecelec' was a French rep firm (represented C&K switches, among others) while Telequipment is what I should have said. As for "Kikutsi', whatever you say. That was my blind stab, I can not even get myself to pronounce their name, let alone to spell it. As for Doug Hale's talk about Telequipment and dual time base, I think that delayed base came from Tektronix and Telequipment just carried that idea on. I can relate to what Doug says about not being willing to go back to a scope without delayed base. You need it once in a blue moon, but when you have to have it, there is no substitute. I cut my teeth on a 454A; after few months had a design problem, I think it was some racing condition and as a result had a nasty dog tooth on an edge, Delayed base saved my neck and after that I just would not touch any scope without dual time base. Actually, I became Tektronix snob, would not touch anything else. Back in 1977, company that I worked for bought a nice storage hp (company was in underwater acoustics, so storage is very helpful), but trigger was a true hp, very hard to adjust and would quickly drift to instability. I never touched that hp scope, except when I needed storage, and even than image would bloom on me. I guess, that was my subconscious attempt to say that nothing short of Tektronix can work right. Regards Miroslav Pokorni -----Original Message-----
From: Phil (VA3UX) [mailto:phil@...] Sent: Monday, August 06, 2001 2:21 PM To: TekScopes@... Subject: RE: [TekScopes] Re: 465M Flaky vertical height. At 01:20 PM 8/6/2001 -0700, you wrote: >I find Don's story fascinating. > >To start with, until very recently I thought that 465M is a 465, in a funny >housing, but still 465. I never new that 465M traces lineage to T900. That's what I thought too. That was an informative post. > I >believe that T900 were products acquired when Tektronix bought (British ?) It was "Telequipment" from the UK >Tecelec; anyone, please, correct me if I am wrong on Tektronix/Tecelec >transaction. I have seen same housing and controls with both, Tecelec and > Sales guy complained how Air Force bought scopes from Kikutsi, >because of low price, while Kikutsi Kikisui ?? Phil >Regards > >Miroslav Pokorni > > > > -----Original Message----- > From: donlcramer@... [mailto:donlcramer@...] > Sent: Sunday, August 05, 2001 2:49 PM > To: TekScopes@... > Subject: Re: [TekScopes] Re: 465M Flaky vertical >height. > > Fascinating! > > BTW, what was the reason for creating the 465M for the >government vs selling > the 465? Was it a cost issue? Or some special features? >Was the 455 an > outgrowth of the 465M or was it the other way around? > > I worked in Digital Service Instruments as a production tech >in the late 70s, > which was a new group in Portables which began with the 851 >Digital Tester. > This was a product designed originally for Burroughs for >their first line > techs as a scope replacement. The instrument was >principally a clever > integration of DMM and counter/timer functions and the idea >was that a tech > could follow a diagnostic tree and compare readings to >arrive at the fault, > without the need to be familiar with how a scope worked. >Anyway, we were > next to the T900 line and if DSI production was a bit slow, >I would get to > work on T900 product. While not as nice as the "real" >portables, the top > line T935 wasn't a bad instrument (2x35MHz) as far as >functionality was > concerned. > > About once a month our group got to either take a tour of >another area, or > had a guest in, as was common practice back then in order to >get more > familiar with other parts of Tek. One time it was the the >marketing product > manager for T900. As you know, the T900 line styling was a >little odd, and > was derided for looking like an old Kerby cannister vacuum >cleaner instead of > like a traditional portable scope. The gentleman, whose >name I've long since > forgotten, was quite a character. He told us he wanted to >do an ad with a > photo of a field service tech holding a T900 in one hand and >a vacuum cleaner > hose in the other hand with the line "Tektronix is Going to >Clean Up in the > Low Cost Scope Business". But the idea was shot down. We >had quite a laugh > over that, and he was an inspiration for the T900 team who >felt somewhat > second rate compared to the groups working on the more >expensive portables > and lab scopes. My recollection is that were a great bunch >of people > regardless of what they worked on. > > Don > > > > > [Non-text portions of this message have been removed] > > > ------------------------ Yahoo! Groups Sponsor > > To unsubscribe from this group, send an email to: > TekScopes-unsubscribe@... > > > > Your use of Yahoo! Groups is subject to > > > > >To unsubscribe from this group, send an email to: >TekScopes-unsubscribe@... > > > >Your use of Yahoo! Groups is subject to ------------------------ Yahoo! Groups Sponsor To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to |
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Re: 465M Flaky vertical height.
Doug Hale
I always wondered what happened to Telequipment. I used a little Dual Trace Dual
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Timebase Telequipment scope in college ~1975. It was a great scope. Stable, easy to setup, and the dual/delayed timebase was was magic. After that one, I wouldn't even consider it a scope without a dual/delayed timebase. I don't even remember the model. Does anyone have a picture of a T900 so I could see if that is the one I used? Doug hale "Phil (VA3UX)" wrote: At 01:20 PM 8/6/2001 -0700, you wrote:I find Don's story fascinating.That's what I thought too. That was an informative post. |
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Re: 465M Flaky vertical height.
Phil (VA3UX)
At 01:20 PM 8/6/2001 -0700, you wrote:
I find Don's story fascinating.That's what I thought too. That was an informative post. IIt was "Telequipment" from the UK Tecelec; anyone, please, correct me if I am wrong on Tektronix/TecelecKikisui ?? Phil Regards |
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Re: 465M Flaky vertical height.
Miroslav Pokorni
I find Don's story fascinating.
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To start with, until very recently I thought that 465M is a 465, in a funny housing, but still 465. I never new that 465M traces lineage to T900. I believe that T900 were products acquired when Tektronix bought (British ?) Tecelec; anyone, please, correct me if I am wrong on Tektronix/Tecelec transaction. I have seen same housing and controls with both, Tecelec and Tektronix names on it. I never new that T900 were built in Beavertron, I thought that all of them came out of UK plant. With my newly acquired insight into 465M, I find story told to me by local former Tektronix sale guy a bit funny (local: Orange County, Ca, former: circa 1982). Sales guy complained how Air Force bought scopes from Kikutsi, because of low price, while Kikutsi could not deliver a scope to meet performance specification. I wander how much of performance would have been met by 465M. Regards Miroslav Pokorni -----Original Message-----
From: donlcramer@... [mailto:donlcramer@...] Sent: Sunday, August 05, 2001 2:49 PM To: TekScopes@... Subject: Re: [TekScopes] Re: 465M Flaky vertical height. Fascinating! BTW, what was the reason for creating the 465M for the government vs selling the 465? Was it a cost issue? Or some special features? Was the 455 an outgrowth of the 465M or was it the other way around? I worked in Digital Service Instruments as a production tech in the late 70s, which was a new group in Portables which began with the 851 Digital Tester. This was a product designed originally for Burroughs for their first line techs as a scope replacement. The instrument was principally a clever integration of DMM and counter/timer functions and the idea was that a tech could follow a diagnostic tree and compare readings to arrive at the fault, without the need to be familiar with how a scope worked. Anyway, we were next to the T900 line and if DSI production was a bit slow, I would get to work on T900 product. While not as nice as the "real" portables, the top line T935 wasn't a bad instrument (2x35MHz) as far as functionality was concerned. About once a month our group got to either take a tour of another area, or had a guest in, as was common practice back then in order to get more familiar with other parts of Tek. One time it was the the marketing product manager for T900. As you know, the T900 line styling was a little odd, and was derided for looking like an old Kerby cannister vacuum cleaner instead of like a traditional portable scope. The gentleman, whose name I've long since forgotten, was quite a character. He told us he wanted to do an ad with a photo of a field service tech holding a T900 in one hand and a vacuum cleaner hose in the other hand with the line "Tektronix is Going to Clean Up in the Low Cost Scope Business". But the idea was shot down. We had quite a laugh over that, and he was an inspiration for the T900 team who felt somewhat second rate compared to the groups working on the more expensive portables and lab scopes. My recollection is that were a great bunch of people regardless of what they worked on. Don ------------------------ Yahoo! Groups Sponsor To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to |
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Re: CONTACT CLEANER
Miroslav Pokorni
On the subject of cleaning labels, I found success with ski wax cleaner for
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cross country skies. I use 'Swix', which is a Scandinavian brand; if anyone used ski wax 'clister' (or however you spell the name for that gooey stuff) you would understand the effectiveness of the cleaner. As a first step I would clean up with alcohol, to remove stuff that cleans easy. Then I would dub some Swix on the label and let it seat for a while; non-permeable labels, like metal or polyester have to be peeled off first and work is on the glue residue. My preferred pads for cleaning are Kimwipes, a lint free industrial wipes; they hold together quite well, too. After an hour or so of socking, I would use the same pad that was used for dubbing, to clean off glue; socking for an extended time period is feasible because wax cleaner is quite thick, consistency of a jelly. When there is a lot of glue residue or it became quite tough over time, only a part of glue would come off. Then repeated application is called for; I never had to go beyond three applications. All painted or etched metal surfaces stand the cleaner without exception, as well as most plastics. The only thing that I would have doubt about is transparent plastic. I tried it on a piece of what I believe was acrylic and surface did get cloudy. It is very important to clean with alcohol the whole area where wax remover was applied. The stuff stinks pretty badly and if you do not clean with alcohol stink will stay with you for long time. The whole operation is best carried outdoors, with usual fire precautions, too; that is a petroleum product. All used wipes should be discarded to outdoor garbage can; possibly, you can use a thicker plastic bag to wrap all used material, but bare in mind that odors quite easily escape. Regards Miroslav Pokorni -----Original Message-----
From: jstanton@... [mailto:jstanton@...] Sent: Sunday, August 05, 2001 10:05 AM To: TekScopes@... Subject: [TekScopes] CONTACT CLEANER For many years we used a contact cleaner "Cramolin Red" which used to be distributed by Caig. I went searching for new supplies and discovered that Cramolin is actually German and that Caig's Deoxit is actually their knock-off of Cramolin and is probably just as effective. We achieved miracles with Cramolin. Temperamental equipment that was plagued with intermittent faults became totally reliable after it was disassembled and all connectors and contacts treated with the Cramolin Red. More recently I have been able to resurrect some Tek plugins and frames that had been stored in a hostile environment by first cleaning switch and other contacts with isopropyl alcohol to rinse away water and alcohol contaminants and then applying Cramolin to attack the oxides and leave a protective, conductive lubricant. This process failed on equipment that had clearly been underwater so dont expect the impossible. I notice that Cramolin is still in business. I just ordered Caig's sample kit and shall compare it to my Cramolin Red dregs and report the result. On the subject of cleaning used Tek equipment my biggest problem has been with labels. I find the following method works: 1. Heat the label and attempt to peel it off. 2. Use "Goo Gone" lemon oil solvent to attempt to dislodge it. This is a mild solvent that seems to be kind to plastics. 3. Add some WD40 if it is stubborn. This is a stronger solvent so take more care with it. 4. Aged label adhesive sometimes still resists and then I carefully use some nail polish remover if there is metal or anodizing underneath, using a moistened pad like an art restorer. 5. On a painted or plastic surface where acetone cannot be used remnants can be removed with a scraper using a similar technique one might use to scrape a bearing or a lathe bed (i.e. no gouging). 6. Finally clean with a pure water and "Red Juice" solution. Red Juice is an industrial cleaner that we use and source from "The Clean Team" in San Francisco. It is a detergent without other additives and leaves no residue, no pine smell, just clean. They also make "Blue Juice" which is great for cleaning glass. My first exposure to Tek scopes was 30 years ago when I carried a 453 to repair mainframe computers (you remember the ones that had thousands of boards and connectors). At that time we knew nothing about contact cleaners and spent endless hours tracing down faults on boards only to find they worked when reseated. Because we used no contact cleaner we would be doing it all over again in a few months time. In retrospect I realize that maybe 90% of our trouble shooting could have been eliminated by treated connectors and contacts. By the way has anyone before or since made a scope like the 453 that could be dropped down a flight of stairs, bouncing off each stair and still work perfectly? Or be in the trunk of a car when the car was totalled and still work? It is a credit to the quality of the materials traditionally used by Tek that a little TLC can bring even very poorly cared for equipment back to near-new appearance and function. Regards John Stanton ------------------------ Yahoo! Groups Sponsor To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... Your use of Yahoo! Groups is subject to |
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Re: Hello-Tek Scopes, Manuals, and Parts
Hi Andrea,
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The switch you are looking for could be obtained from almost any 2 or 3 series dual trace plugin such as a 3A1 or 3A6. That ground/AC/DC switch is the same in all of the units except for some are douple pole and some are single pole. The 3A72 only nees a single pole so either switch would work. Jim --- Andrea Bovo <ivbov@...> wrote: ----- Original Message ----- __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger |
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FAA story
Windsor
Hello,
Great story about FAA/gov't mindset. Reminds me of the story I heard about a company upgrading their servers and the sales guy recommended using linux and saving a big bundle of cash and improve reliability. But the company decided to go with a Microsoft solution because the linux system was saved them too much money. Something to do with a tax deduction. Windsor Chan _______________________________________________________ Get 100% FREE email for life from Excite Canada Visit |
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