Need advice in purchasing oscilloscope

Discussion in 'General Electronics Chat' started by tomb, Oct 1, 2009.

  1. tomb

    Thread Starter New Member

    Oct 1, 2009
    Hello, First off, I'd like to say that I'm an experienced engineer but this is my first foray into low cost oscilloscopes. I'd like some advice on purchasing an oscilloscope to use in a home based test system. I've been looking @ the following scopes: 1. PC based scopes (PicoScope 5203 (8 bit, 250Mhz BW), CleverScope CS 328A (14 bit, 100Mhz BW), and Acute 1202 (9 bit, 200Mhz). 2. New bench top scopes (Lecroy WaveAce 232 (8 bit, 300Mhz) and Tektronix 2022 (8 bit,200Mhz). 3. Used scopes from ebay (TDS644B (8 bit, 500Mhz). I'd prefer a high BW/performance scope, such as the TDS 644B, but it would be very well used and not under warrenty. Next I like the WaveAce but I plan on using LabView to run my system and there is no driver for the WaveAce. The TDS 2022 can be used with Labview (it comes with a free version that runs some of the Tek instruments, and to go to the professional version only costs $700.00 (instead of $4,300) extra if you own certain Tek instruments. The PC scopes are attractive from a footprint point of view and I like the fact that they make use of the computer screen and processing power, but I can't find a PC scope with the bandwidth I want a the price I can afford. I budgeting no more than $2,500.0 for the scope so I'm limited to my choices. Thanks for your help.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    "Home based test system" does not say what gets tested. If it's audio, try to find an analog o'scope - the ailiasing problems with DSO's can be frustrating.

    Think about resolution, too. The difference between 8 and 14 bits is almost unimaginable.
  3. joulian

    Active Member

    Aug 27, 2009
    I thought there was some way of making an old computer into an oscilloscope?
  4. Wendy


    Mar 24, 2008
    New or old, newer is better. If you're refering to the PC oscope it isn't that good, barely functional. You can't measure DC, frequecy range is limited (300Hz to 18Khz), among other things.

    A USB interface, where the computer is just a display (as opposed to using the sound card) has all the pluses and minuses of a digital oscope, including aliasing (a definate negitive). Overall I'm impressed what you get for the money, but they do have flaws from what I can see.

    I got lucky. I bought an old HP120 for $10 around 15 years ago. Actually I bought around 5 of them, 2 functional for $10 ea and $5 for the other 3, which had problems, from an HAM club. If you find the specs for a HP120 it is a peice of crap, but it does audio and a bit above quite well (300Khz roll off, around 100KΩ input inpedance). It is still great for the kind of work I do.

    For the money you offer you should be able to get a decent used scope with all the bells and whistles. My experience with HAMs is almost pure positive, they will usually give you a verbal list of everything that ever happened to their merchandise, it's flaws, and their improvements, being a gabby bunch, and they do care about their reputations. My point is look at whom your buying from, it matters quite a bit.
  5. someonesdad

    Senior Member

    Jul 7, 2009
    You don't say what it is you're going to measure, so it's hard to know what to say. I've not used the PC scopes, but unless I was travelling with a laptop and needed small size, I suspect the lack of a control panel would drive me crazy. I am continually interacting with the knobs and buttons while using a scope and I've never seen a PC GUI interface that comes anywhere near the ease of use of a typical scope's control panel.

    About 5 years ago I bought a used 4 channel HP digital scope on ebay; the scope was made around 1991. I really like the scope and felt I got a good deal on ebay for it. I'd definitely buy another used scope if I liked the buyer's feedback and they offered a one or two week right to return it if I wasn't happy with it.

    I really like the digital scopes' ability to store a waveform for later analysis (how many of us learned to hate the Polaroid cameras?). But I've not used a digital scope that triggered as well as most analog scopes. My sample size is woefully small, but I think it is a pretty good generalization. I never have had a chance to use the expensive HP or Tek scopes; maybe they behave better. Regardless, I could never afford one for hobby work.
  6. Jack_K

    Active Member

    May 13, 2009
    As previously stated, check ebay. I bought a working Tektronix 465 for $75.00.

  7. bountyhunter

    Well-Known Member

    Sep 7, 2009
    I found a good condition used TEK 7834 on ebay for $200 with working plug ins.
  8. BMorse

    Senior Member

    Sep 26, 2009
    For PC based scopes I use the Intronix Logicport 34 channel logic analyzer for what I do and it has worked quite remarkable for a PC based one....(my Tektronix Logic Analyzer is now gathering dust on the shelf since I purchased this unit)

    My .02