scope, CRO, oscilloscope: what to look for?
2008-10-17 16:33
oscilloscope: I'm in the market for one in my robotlab. What should I be looking for and what should I look out for? Any dos and don'ts?
"depends on what you need and how much you want to spend Rik"
Alrighty: No more than 300 Euro for a new one, I suppose. And I want to use it for analysis of PWM signals up to, say, 100 kHz and of electrical noises in circuitry. I'm guessing two channels or better. Does a trigger make the scope much more expensive?
Does a brand make any difference? Any makers I should avoid? How about second hand scopes? Any tell tale signs the box is near death? What about accessories?
The USB connectable little ones (PC scopes, software scopes) seem like a cheap deal, but I think I'd prefer to have a stand alone box on my bench.Any thoughts to persuede me otherwise?
8ik
Hi Rik, Funny I remember
Hi Rik,
Funny I remember asking myself the same questions ... unfortunately I only had myself (at that time I just spoke to myself, and didn't have many answers).
If your interested in FREE you might want to try out XOScope.. I started with this a long time ago. It uses the sound card for an input device - although looking at the site recently I noticed they have support for comedi drivers (this really intrests me ... it offers extensions to a huge range of DAC and DIO cards) also they have DIY instructions on how to make 100 Mhz digital analyzer on the cheap.
I found an old HP from a salvage company for $10, I'm a good scrounger. Its old and I think it got dredged up from the bottom of a river at one point. The scan line occasionally disappears - i unplug the thing and plug it again later it.. and sometimes I get lucky and it appears..
All my experience has been hacking stuff together and trial and error with no professional input. BOA and maybe JIP does this stuff at work.
I'm thinking of going back to XOScope ... I think it has alot of bang for the buck $0 .
Depends how much you want to...
Well, there's no point in saying it. One thing I will inject: I find myself debugging communications lines a lot. For this you simply MUST have a storage scope. My Hameg is a CRT. I was lucky enough to find it in a skip! No kidding. Perfectly good 20MHz dual channel scope. It's not a storage scope, but what do you want for free? (Apparently, I'm a godo scrounger, too!) I think you can get them second hand for under 100 Euro.
You could just about get a 2 channel 20MHz DS scope on eBay for 300 Euro. Spend all the money you can afford. It's money well spent. I don't think there are "bad" scopes.
If I had the money, I really like my scope in work. It's a 4-channel 100MHz Tektronix storage scope with ethernet. So I can upload screenshots and take remote control of it from my PC. That's remarkably handy for triggering remotely. BUT, they're 3,000 Euro!
Now, if you want value for money, my colleague SWEARS by THIS. You need a PC, but it's a 2 channel storage scope for under 200 Euro.I've not used them, but I'd put it on the Christmas list.
storage
Storage probably means the image stays on the tube after the signal was gone already? No need for that if the signal keeps repeating, like a (steady) pwm.
8ik
Yes
DSO PC scope
conrad sells those (under their own brand Voltcraft) for EUR 209 (40 MHz) and EUR 365 (60 MHz).
GBP 90 seems a lot more attractive. Hmmm. Hongkong. VAT, customs, shipping. No rush decisions tody.
so ebay it is
trawling through the adverts
Did not yet find The Find, but I'll lurk around a bit longer. Turns out that most sellers offer "vintage" or "look what I found in the shed" CRT scope. Often without probes or even power cable.
Local offers (i.e. in the Netherlands) seem very rare on ebay. So I am looking at German or British offers. Which means I cannot test the merchandise myself. Although on the dutch marktplaats.nl I do find some locals. Some of the sellers are polite enough to categorize their boxen as antiques.
It would also seem that for storage or memory, I need to go digital. Not much 2nd hand stuff there. Found an Aberdeen seller selling new stuff (brand OWON?), starting at EUR 280.
8ik
Take your time
Definitely choose carefully. THIS scope is identical to mine. That's about 150 Euro. I've seen them sell for half of that.
I am equally cautious of buying expensive eBay items from HK / China.
popular hm203-6
Useful vs interesting
no hacks this time
You must...
You have to try this. It's a laugh if nothing else.
http://www.chrismeighan.com/projects/scopeshapes
I'm tempted to hook it to THIS and see what happens...
scopeshape and dxf
Important