Second-hand TDS-340AP oscilloscope get! - Page 1
Forum section: electronics / beginners

author: houkensjtu
author_rank: Contributor
timestamp: May 22, 2015, 06:17:21 am
content: Hi!I found this bad boy in local market, cost me about 130 dollars. It's my first oscilloscope! LOLIts spec is quite high-end for beginner I think, features 100MHz bandwidth, 500MS/s sampling rate and even more, it comes with a GPIB capturing card!What I'm little disappointed about is, this guy is over 45cm in depth!! That's gonna be really hard for me to find a proper place on my working bench for it.For the time being I still don't have idea on how to play with, maybe I will use it to observe my hand-made experiment power supply behavior.Post anything you thought!

author: tron9000
author_rank: Frequent Contributor
timestamp: May 22, 2015, 07:55:24 am
content: Quote from: houkensjtu on May 22, 2015, 06:17:21 amGPIB is something I've not used, but from my experience, its somethingNOBODYever used. We got some nice Tektronix TBS1052's in our labs and the software to get screen grabs off them is default set to bloody GPIB! Why?! when it has a perfectly good USB connection to use!!....coming back on track, 45cm, meh, for anyone who's owned a traditional CRT, this has always been an issue, you find a way to make it fit, least you don't have it this bad:(this is a movie prop - it could be the machine that goes PING!)Most importantly -do you have a good set of probes?

author: dom0
author_rank: Super Contributor
timestamp: May 22, 2015, 09:36:29 am
content: Quote from: tron9000 on May 22, 2015, 07:55:24 amNot true. Also, USB sucks for multiple reasons (extensive driver headaches, unreliable connections, bad platform compatibility (cf. driver headaches))

author: tron9000
author_rank: Frequent Contributor
timestamp: May 22, 2015, 09:57:13 am
content: Quote from: dom0 on May 22, 2015, 09:36:29 amFair enough, its only as good as the platform and drivers its build on.But USB is everywhere now. ok you can buy a GPIB PCI card, used as low as £30, but some are going for £80-£100, seems to be even more if you want PCI-Xpress. USB-A to B cable, most of us have floating in a drawer somewhere, practically free.When was the last time you saw a GPIB card on a PC- scrap that, you probably have one!Ok you can get USB to GPIB converters too, cheapest I search for was £78.Anyway this is not to put off houkensjtu of his purchase, looks like a good score.

author: c4757p
author_rank: Super Contributor
timestamp: May 22, 2015, 10:15:30 am
content: It's a simple parallel bus. Grab a bloody Arduino or something, and a service manual from one of the early GPIB instruments (they often had a section that explained it in detail, and was quite easy to understand) and just make your own. It's not hard to shove some bits out.(Was going to say thattheseare relatively cheap, but, I suppose an HTTP 500 error isreallycheap)

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: May 22, 2015, 10:34:29 am
content: If you have the floppy disk, you can use it to save plots in postcript and print it later on using a computer.This is what I am doing with a TDS460 (4 ch version). Very convenient.Its quite easy to find some old floppy disks around.

author: houkensjtu
author_rank: Contributor
timestamp: May 22, 2015, 12:48:58 pm
content: Quote from: tron9000 on May 22, 2015, 07:55:24 amHaha your picture is funny, but for now I DO WANT such a shelf cause it just take too much space on my desk...And you are definitely right, I bought myself a pair of probe.(see the attachment)The quality is quite decent, plastic parts are well-made, also packed with a plastic screw-driver which is really handy. Cost me another $13...

author: houkensjtu
author_rank: Contributor
timestamp: May 22, 2015, 12:51:30 pm
content: Quote from: JacquesBBB on May 22, 2015, 10:34:29 amThank you for this information!Actually I'm a linux user so I'm extremely happy with postscript figure, but unfortunately who has a floppy driver nowadays...

author: houkensjtu
author_rank: Contributor
timestamp: May 22, 2015, 01:01:33 pm
content: Quote from: tron9000 on May 22, 2015, 09:57:13 amThat's true. I didn't consider about that yet, £30 is absolutely not cheap.The reason why I'm exciting about GPIB capturing card is that I've been writing some simple data-acquisition program in python, in our company's lab.Also there is more than GPIB interface, actually there is a RS232 port so I think it maybe fun to make my own rs232 cable and observe the serial communication waveform on itself!

author: houkensjtu
author_rank: Contributor
timestamp: May 22, 2015, 01:05:20 pm
content: Quote from: c4757p on May 22, 2015, 10:15:30 amYeah that sounds exiting!I really want to dig into the serial communication area and that's one of the important motivation for me to buy this scope. I've heard that usb waveform are really fast and crazy that can not be observed by normal oscilloscope, how about GPIB siganl?

author: dom0
author_rank: Super Contributor
timestamp: May 22, 2015, 01:25:38 pm
content: Depends on what speed you are after. 1 or 11 MBit/s are easily observed with medium bandwidth scopes (100+ MHz), you need, however, proper probes. For Hi-Speed (480 MBit/s) a really fast scope with at least 2 GHz bandwidth is to be used ; there are lots of information about how to test USB connections and what kind of text fixtures you need out there.GPIB waveforms are generally not overly fast (TTL outputs with quite some capacitive loading), expect rise times in the order of 10+ ns. The fastest response in a GPIB system is the response to ATN (limit: 200 ns).