EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: thoughtyness on July 11, 2018, 02:57:18 am
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I'm looking for my first oscilloscope and found this. I can't spend much more, so should I get this, or keep looking for something else, in which case, what scopes would you recommend?
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Sounds great, as my 1st scope I got a tek2430a for $180, about 50 was probably for shipping from US to Canada.
I've since had to buy 2 CCD hybrid chips tho, thats the most thing about these, the custom chips.
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so should I get this, or keep looking for something else, in which case, what scopes would you recommend?
you can get it, or keep looking for something else, such as rigol ds1054z. the former, be prepared for additional probes price, if it has none.
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I have two old TEK scopes and love them both, a 475 and a 2225. That said, they are complicated machines and 30+ years old. $100 for a working 2245 is an excellent price, but many of these old scopes are a problem waiting to happen. Parts can be hard to find and even something as simple as a 50 cent capacitor can be a challenge for someone new. You can get a legitimate 2 channel digital scope, brand new with a warranty, for $250 on Amazon and I am sure on other places. Siglent, Rigol, Owan ect. They are not cutting edge technology, but are certainly fine for a beginner. An old analog scope can make a great second scope, but I would recommend you stick to something new, wait until you can afford it if you have to. My 2 cents
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I've never used a Tek 2445, but for a $100 for a working Tek scope, I don't see how you can go wrong. It's not fully analog, so there are probably pure unobtainium parts in it. But service manuals are available. And it's new enough that it's not socketed transistors like the 400 series.
Forty years ago I paid $75 for a 5 MHz recurrent sweep Heathkit IO-18 and was thrilled. I learned a lot from that scope. Twenty years later I bought a socketed transistor Dumont 1060 with a 30 day warranty. It ran for about 35 days before dying of a bad solder joint. It sat for several years until I got a semi-functional Tek 465. It worked just well enough for me to fix the Dumont which I then used to fix the 465. All the problems I encountered were cracked solder joints. I learned a *lot* about scopes in the process.
I have 3 DSOs, but am about to buy a refurbished Tek 485 for the simple reason it is purely analog and I *know* exactly what it is showing me. I have had recent adventures with bugs in DSOs from top tier OEMs that list for $15-20K. They did not inspire me with confidence. Which is why I want the 485.
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Sounds reasonable to me, $100 for just about any fully working scope from a reputable brand is a decent deal.
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I have 3 DSOs, but am about to buy a refurbished Tek 485 for the simple reason it is purely analog and I *know* exactly what it is showing me. I have had recent adventures with bugs in DSOs from top tier OEMs that list for $15-20K. They did not inspire me with confidence. Which is why I want the 485.
The Tek 485 has another "hidden" advantage: the 50ohm input goes directly to a 50ohm attenuator, so the input impedance is 50ohms. On many scopes the 50ohms is merely a 50ohm resistor connected in parallel with the input, so the input impedance is 50ohm//20pF.
RF people will know what that implies, where "RF" also means anybody that understands modern digital logic circuits less than 25 years old :)
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That is a GREAT price.
But this being your very first scope, how do you know it's fully working? I have been buying second (or third) hand scopes for some time now and I have yet to find one that has absolutely zero issues. There's always something. Sometimes, it's something silly and sometimes it's beyond reasonable to even try to fix. Sometimes problems are obvious, sometimes it's intermittent, or subtle.
Once you are familiar with functions and how-to, it'll be easy to identify when something isn't working. But if you've never had one, how would you know if it's supposed to be THAT way? I don't know if I recommend it, to be honest. I'd go with something low-end and new.
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good deal for a working one.
in general, look at eBay "sold" listings to get a general idea of going prices for scopes in similar condition.