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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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opinions on buying a scope
Hey all;
I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? Thanks |
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opinions on buying a scope
You make me all confused, you say you built and designed a couple of audio
stuff.... hmm. without an o-scope??? That's the FIRST thing you need to see the results of your *audio* projects, my friend! I don't think you'll need anything better than a simple 2channel 20MHZ scope... Cheers Stefan "tempus fugit" skrev i meddelandet ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? Thanks |
#3
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opinions on buying a scope
"tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? Thanks If all you're going to do is audio work, the cheapest scope you can find would work just fine. My first scope (in 1956) only had a 5 Mhz bandwidth. My present scope is a dual channel, 100 Mhz. The old 5 Mhz would be a good one for audio. I've had no experience with the PC scope, but it would be worth a try. |
#4
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opinions on buying a scope
"tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? There is so much stuff on scopes that you will find too much. Here is one example: http://www.qsl.net/wd1v/scopefaq/index.html Tektronix, Agilent, and others have some really good stuff in the way of tutorials and application notes. For me, a scope is the best instrument in the lab. In fact, if I can have only instrument, it's going to be a scope. Others do nicely with other test equipment. I suppose it's a matter of what one is used to and how one visualizes circuit operation. As to a used scope, there are some great buys out there. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. |
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opinions on buying a scope
Charles Schuler wrote:
"tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older [....] There is so much stuff on scopes that you will find too much. Here is one example: http://www.qsl.net/wd1v/scopefaq/index.html Tektronix, Agilent, and others have some really good stuff in the way of tutorials and application notes. For me, a scope is the best instrument in the lab. In fact, if I can have only instrument, it's going to be a scope. as a computer Field Engineer, until just the last few years a scope was absolutely required, you could get by w/o a meter but not a scope and a flashlight. Others do nicely with other test equipment. I suppose it's a matter of what one is used to and how one visualizes circuit operation. i like the ones that can give dvm readouts on the crt, pricy i suppose, but you s/b able to find a used scope with the integral dvm. As to a used scope, there are some great buys out there. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. my opinion is that if you don't need 150-300mhz or higher, stay away from well used "pro" units that go cheap (like a Tek 465) w/o a manual and unknown hours of use. if that puppy goes TU, you are screwed, it just became a boat anchor (it will weight about that much, too). used "consumer/technician" scopes are getting more common and may sell for about the same price as the super duper pro model but it likely is nearly in NEW condition, s/b much more reliable, and will weight 1/4 as much. i have a dual trace 40mhz Hitachi, paid 600+shipping in 1987 or so, it will last me another 30 years, but would only bring (these days) $100-200 in the DFW area. good luck, --Loren |
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opinions on buying a scope
Thanks for your reply Charles.
The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. So do scopes often fail? "Charles Schuler" wrote in message ... "tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? There is so much stuff on scopes that you will find too much. Here is one example: http://www.qsl.net/wd1v/scopefaq/index.html Tektronix, Agilent, and others have some really good stuff in the way of tutorials and application notes. For me, a scope is the best instrument in the lab. In fact, if I can have only instrument, it's going to be a scope. Others do nicely with other test equipment. I suppose it's a matter of what one is used to and how one visualizes circuit operation. As to a used scope, there are some great buys out there. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. |
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opinions on buying a scope
"tempus fugit" wrote in message ... Thanks for your reply Charles. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. So do scopes often fail? The ones from companies like Tektronix are generally reliable. However, used ones can have a lot of miles on them and might have been subjected to harsh environments and abuse by users. We had (where I used to work) dozens of Tektronix scopes and about a dozen Hitachis. They generally held up well but there were a few problems. You know how it is with electronic equipment. Ten people will swear by brand X and then one will come along and bad mouth that same brand. You might consider an inexpensive, used scope that you can return if it does not work. If you find that you really like using it, then it might be time to invest in a better one. I have seen some nice buys at hamfests. Are there any in your area? The vendors are often locals who will be less likely to screw you. I'd bet that if you are serious about amplifiers and electronics that you will quickly become a scope fan. A picture is worth a thousand meter readings! |
#8
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opinions on buying a scope
"Charles Schuler" wrote in
: "tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? There is so much stuff on scopes that you will find too much. Here is one example: http://www.qsl.net/wd1v/scopefaq/index.html Tektronix, Agilent, and others have some really good stuff in the way of tutorials and application notes. For me, a scope is the best instrument in the lab. In fact, if I can have only instrument, it's going to be a scope. Others do nicely with other test equipment. I suppose it's a matter of what one is used to and how one visualizes circuit operation. As to a used scope, there are some great buys out there. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. FYI,for a hobbyist who wants a low cost used TEK scope that uses NO custom ICs,the TEK T922/932/935 (or the TEK 442) are nice scopes that are relatively new.BW of 15-35 Mhz.Easy to work on. TEK 422 is an older scope that I have good regard for,too,15 Mhz. TEK 453,50 Mhz,IIRC. TEK 454,150Mhz IIRC. Avoid 200 and 300 series TEK scopes,IMO. -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
"tempus fugit" wrote in message So do scopes often fail? The older scopes have electrolytic caps that fail,switches/pots that get dirty or noisy. -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
In article , Jim Yanik wrote:
FYI,for a hobbyist who wants a low cost used TEK scope that uses NO custom ICs,the TEK T922/932/935 (or the TEK 442) are nice scopes that are relatively new.BW of 15-35 Mhz.Easy to work on. TEK 422 is an older scope that I have good regard for,too,15 Mhz. TEK 453,50 Mhz,IIRC. TEK 454,150Mhz IIRC. How does the 454 compare to the 475? -- uns |
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opinions on buying a scope
Avoid 200 and 300 series TEK scopes,IMO. Do you also mean to avoid 2000 and 3000 series scopes? I see a few of those on eBay. Thanks |
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opinions on buying a scope
What about other brands like Hitachi and B&K Precision?
"Jim Yanik" wrote in message .. . "Charles Schuler" wrote in : "tempus fugit" wrote in message ... Hey all; I'm thinking about adding a couple things to my test equipment arsenal, and I was thinking about a scope. I've seen quite a few on eBay going fairly cheap, but I'm not sure what I need for capability (or even if I really need a scope) My main diagnostic tool is a DMM. I mostly work with audio stuff (built and designed few things) and the odd repair for a family member of some piece of consumer gear, so I don't need anything too intense I don't think. What kind of bandwidth is useful? I'm guessing there are some older scopes out there with such limited bandwidth as to be useless anymore (maybe that's why they're so cheap). What about a PC scope (hardware or soft - although I suppose the software type will be limited to 20kHz bandwidth). Can anyone point me to a good tutorial site on how to use a scope, applications, tricks, etc? There is so much stuff on scopes that you will find too much. Here is one example: http://www.qsl.net/wd1v/scopefaq/index.html Tektronix, Agilent, and others have some really good stuff in the way of tutorials and application notes. For me, a scope is the best instrument in the lab. In fact, if I can have only instrument, it's going to be a scope. Others do nicely with other test equipment. I suppose it's a matter of what one is used to and how one visualizes circuit operation. As to a used scope, there are some great buys out there. The problem is getting parts. Many scopes use proprietary ICs that cannot be purchased. I know people who buy two (or more) of the same model and use one for parts. Good luck. FYI,for a hobbyist who wants a low cost used TEK scope that uses NO custom ICs,the TEK T922/932/935 (or the TEK 442) are nice scopes that are relatively new.BW of 15-35 Mhz.Easy to work on. TEK 422 is an older scope that I have good regard for,too,15 Mhz. TEK 453,50 Mhz,IIRC. TEK 454,150Mhz IIRC. Avoid 200 and 300 series TEK scopes,IMO. -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
In article , Uns Lider wrote:
In article , Jim Yanik wrote: FYI,for a hobbyist who wants a low cost used TEK scope that uses NO custom ICs,the TEK T922/932/935 (or the TEK 442) are nice scopes that are relatively new.BW of 15-35 Mhz.Easy to work on. TEK 422 is an older scope that I have good regard for,too,15 Mhz. TEK 453,50 Mhz,IIRC. TEK 454,150Mhz IIRC. How does the 454 compare to the 475? -- uns iirc, these are different generations, both dual trace "Field" scopes. the 475 was the least favored of the three in that series, more expensive/less reliable than the 465, and way lower performance that the topline 485. the 485 was considered the best in class and was reliable. all had delayed sweep. these all are very old, 40yrs? so caveate emptor. --Loren |
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opinions on buying a scope
Loren Coe wrote in
news:KFrUa.132758$GL4.34318@rwcrnsc53: In article , Uns Lider wrote: In article , Jim Yanik wrote: FYI,for a hobbyist who wants a low cost used TEK scope that uses NO custom ICs,the TEK T922/932/935 (or the TEK 442) are nice scopes that are relatively new.BW of 15-35 Mhz.Easy to work on. TEK 422 is an older scope that I have good regard for,too,15 Mhz. TEK 453,50 Mhz,IIRC. TEK 454,150Mhz IIRC. How does the 454 compare to the 475? -- uns iirc, these are different generations, both dual trace "Field" scopes. the 475 was the least favored of the three in that series, more expensive/less reliable than the 465, and way lower performance that the topline 485. the 485 was considered the best in class and was reliable. all had delayed sweep. these all are very old, 40yrs? so caveate emptor. --Loren 485 has a complex switching power supply that is a tough one to repair,the scope uses more TEK-made IC's than any other 400 series portable. 454 was a good scope,but is a generation behind the 475. 454 has no TEK-made ICs,475 has several;in the vertical,trigger,and sweep circuits. TEK-made IC's are no longer made,no longer available from TEK.Only from cannabalized scopes or perhaps some folks (other than TEK-US) still have some stock of new ICs in their bench stock or toolbox.( a real long shot!) -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
"tempus fugit" wrote in
: What about other brands like Hitachi and B&K Precision? I have no knowledge,experience with,or opinions of any of them. -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
Jim Yanik wrote:
"tempus fugit" wrote in : What about other brands like Hitachi and B&K Precision? I have no knowledge,experience with,or opinions of any of them. Hitachi is good, imho, i own a 35mhz dual trace, new in 1985 or so. nice sw's and has "uncal" led/s. unusual for a 600.00 scope. manual has shematics and it is light-weight (14lbs?). --Loren -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
I think the 465 is not a dual trace scope (correct me if I'm wrong). How
important is it to have the dual trace? Also, is it important that the scope be calibrated when I buy it, or is this fairly easy to do on your own? Thanks "Jim Adney" wrote in message ... On Sat, 26 Jul 2003 09:16:27 GMT Loren Coe wrote: iirc, these are different generations, both dual trace "Field" scopes. the 475 was the least favored of the three in that series, more expensive/less reliable than the 465, and way lower performance that the topline 485. the 485 was considered the best in class and was reliable. all had delayed sweep. these all are very old, 40yrs? so caveate emptor. The 453 (60MHz) and 454 (150MHz) came out in the late 60s. The 465 (100MHz), 475 (200MHz), 475A (250MHz) and 485 (350MHz) all came out in the 70s, if not in 1970. These have somewhat larger displays than the 45x scopes. The 465B (100MHz) came out in ~1980 as a replacement for the 465. The other models continued for another ~10 years. The 465/465Bs were some of Teks most popular scopes ever. They would be my first choice for a used Tek scope except that I already have one. The 485 was really not in the same family. It was physically larger and more complicated and had a completely different power supply that is difficult to troubleshoot. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
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opinions on buying a scope
lcoe wrote in
news:%dkVa.2020$uu5.525@sccrnsc04: tempus fugit wrote: I think the 465 is not a dual trace scope (correct me if I'm wrong). How wrong. it certainly is. important is it to have the dual trace? Also, is it important that the scope well, if you want to compare timing or look at more than a single signal, it is almost essential. lot's of lab scopes went to 4 trace long, long, ago. be calibrated when I buy it, or is this fairly easy to do on your own? Thanks that, i dunno. if you are making a living with the thing, better get it calibrated. otherwise, find some known frequency and calulate it for yourself. 60hz power is the only common that i have used. there s/b others, tho, maybe in tv's? --Loren there's more to calibration than just checking the time-base(especially at ONE range). Attenuator compensation can change,freq.response,trigger sensitivity and DC trigger levels.Attenuators can also go out of tolerance;voltage inaccuracy.I've seen where only a few timing ranges were in error,too. -- Jim Yanik,NRA member remove null to contact me |
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opinions on buying a scope
"tempus fugit" wrote in
: I think the 465 is not a dual trace scope (correct me if I'm wrong). How important is it to have the dual trace? Also, is it important that the scope be calibrated when I buy it, or is this fairly easy to do on your own? Thanks For a proper calibration,you need a known timing standard;with time marks from 5 sec to 10ns,a variable amplitude sq.wave generator,up to 60Vp- p/100Khz,an amplitude calibrator.The 465 service manual lists suggested calibration equipment,at the beginning of the cal procedure.(just checking with 60 hz line freq is not going to do it.) It's not hard at all if you have the right equipment. 8-) -- Jim Yanik,NRA member remove null to contact me |
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