EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Dannyx on December 11, 2024, 05:47:20 pm
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Good day folks. What's your opinion on the following scopes:
A USED Tektronix 7834 (https://w140.com/tekwiki/wiki/7834)
vs.
a NEW Uni-T UPO1204 (https://uni-t-shop.eu/products/upo1204-digital-oscilloscope?srsltid=AfmBOoofhW6GTTxUnvvFAkhis5vuOgGxlCiS190xu_33lbQ_kaub4R-Q) ?
Bearing in mind that I never used an oscilloscope before and don't know that much about them, but I DO try to cram in as much info as possible for when the time comes to get my first one in my shop. I guess it also depends on what I plan using them for and I don't have a definite answer for that: just generic repair stuff an electronics repair shop usually deals with and I feel I would've been able to tackle better IF I had a scope.
In this case, the listing for the Tektronix is considerably cheaper than the Uni-T, the only downfall being that it's a "vintage", used device, which probably lacks some features a brand new tool like the Uni-T has out of the box, despite the higher upfront cost. There's also the obvious chance of something failing internally after all these years, which is true for used gear in general...
Those who know their scopes and this one in particular, will surely ask about the modules this particular Tektronix comes with, so the chap sells it with:
-1x 7A19
-2x 7A26
-1x 7B85
-1x 7B80
I haven't done any in-dept study on either of these scopes, much less so on the individual modules the Tektronix accepts - I just looked at some of the basics, as much as I could comprehend them. For instance, I don't expect to be able to connect the Tektronix to my PC any time soon....at least not easy. I'm also pretty sure it won't be that easy to score additional modules for the Tektronix and whether or not that matters anyway. Hope that gives you some info to work with.
Thanks.
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You would be much better with something like this:
https://www.batronix.com/shop/oscilloscopes/Siglent-SDS1104X-E.html (https://www.batronix.com/shop/oscilloscopes/Siglent-SDS1104X-E.html)
https://www.batronix.com/shop/oscilloscopes/Siglent-SDS804X-hd.html (https://www.batronix.com/shop/oscilloscopes/Siglent-SDS804X-hd.html)
The BW and Options upgrades are DIY.
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7834s are very cool when they have a good CRT, but definitely not suitable as your first or only scope. Get something newer (and cheap), and then upgrade later, when you know more about what you need.
There is no straightforward way to connect a 7834 to a PC.
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You would be much better with something like this:
https://www.batronix.com/shop/oscilloscopes/Siglent-SDS1104X-E.html (https://www.batronix.com/shop/oscilloscopes/Siglent-SDS1104X-E.html)
https://www.batronix.com/shop/oscilloscopes/Siglent-SDS804X-hd.html (https://www.batronix.com/shop/oscilloscopes/Siglent-SDS804X-hd.html)
The BW and Options upgrades are DIY.
+1
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7834s are very cool when they have a good CRT, but definitely not suitable as your first or only scope. Get something newer (and cheap), and then upgrade later, when you know more about what you need.
There is no straightforward way to connect a 7834 to a PC.
+1
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Are the 7834 & modules working, are suitable probes included?
These are not the easiest things to work on, access can be difficult without the special extender for the modules. Another oscilloscope will probably be needed to maintain it, even if it works fine at the moment.
On the plus side it is 400MHz and service info is available, unlike most modern landfiller grade scopes.
The input protection in the 7A19 is a very expensive custom RF fuse, don't know about the 7A25, the wiki isn't working for me tonight.
Edit: it's partly working now, is 7A25 the correct number? wiki suggests it never went into production.
David
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Whoops. My bad - my finger must've went too far to the left :D It's 7A26 indeed.
The chap sells it as "functional", but doesn't offer any in-depth details and that includes whether it includes any probes or not, so that's another stab in the dark, though I'm sure I could obtain that info if I chatted him up and was determined to get it. Having said that, it certainly LOOKS like a complicated and professional tool for its era, so I may find myself in hot water if I get it only to discover that A) I don't know how to use most of it and B) something doesn't work and requires tinkering, as my experience with fixing scopes is sub-zero :D
At least a new product is covered by warranty to some degree....
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I have a pair of 7834s and recommend against buying one unless you have a specific application and 7000 series plug-ins which require it. All of the 7000 mainframes are old enough to require refurbishment at this point, like cleaning of the potentiometers and rebuilding of the switching power supply.
Do not underestimate the shipping either. The CRT of one of my 7834s has poor geometry and I suspect it was damaged during shipping.
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Maybe you could start with something simpler/cheaper
like a $70-100 handheld scope:
Zeeweii DSO3D12, Hanmatek HO52, Zoyi/Zotek ZT-703S, etc.
You can get something better when/if you outgrow it.
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I had some experience with Uni-T (Europe) devices in the last few months. They all have quite some major issues (For their prices - even if cheap). But i also tried to get support from them, but they used EVERY bloody excuse to not give me any support. They did not even pay for the return shipment after they gave me false informations about sending it to them.
It also depends what you want to do with it. But a nice old 500MHz scope has its uses too.
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for the given uni-t prices i would go on siglent sds1000x series plus bw hacks and new probes to fit the updated bw
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Thanks for the info. The gist of it seems to be the Tektronix is a poor choice in my particular case - not that it's a bad tool in itself, but not suitable for my use case. That's for tech buffs who know their stuff. It'd be like buying a classic car as my ONLY daily-driver car - bad idea.
Maybe you could start with something simpler/cheaper
like a $70-100 handheld scope
Are those any good and worth my time ? I wouldn't mind spending a "considerable" amount upfront to get an instrument that's still relevant after many years, instead of buying several cheaper gadgets over time because they proved insufficient in the long run, which would eventually only add up to the price of the "proper" one. As an added issue, I'd then be stuck with all this obsolete gear I'd have a hard time selling because nobody would buy it...
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I would not recomend to buy these cheap toy scopes. Usually this makes your life painful. And you spend more time to understand the drawbacks of the instrument than learn about to work with an oscilloscope. As tv84 already stated, buy something like the cheaper Siglents. They are more expensive but you even can use these scopes when you are already an expert.
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just generic repair stuff an electronics repair shop usually deals with and I feel I would've been able to tackle better IF I had a scope.
I had much success with a cheap 120€ tiny digital scope and an old analog one. But i did not repair that much. For example: i found a malfunctioning positioning sensor of a car with a DSO nano.
Those better scopes would only make sense, if you would look for EMI problems, are designing some switching circuit ,some filters or similiar stuff.
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I would not recomend to buy these cheap toy scopes. Usually this makes your life painful.
I wouldn't say that, because a small portable scope and a benchtop scope are not the same thing and have different advantages.
You can buy a bike first and later a car and continue to use the bike where it has advantages.
I don't see a problem there at all.