Oscilloscope needs probe!

Discussion in 'General Electronics Chat' started by Mike Nelson, Dec 30, 2014.

  1. Mike Nelson

    Thread Starter New Member

    Dec 30, 2014
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    0
    Hey,

    I have a 1010A Ballentine scope that needs a probe. I have a probe for a 585a tektronix but don't know if they are compatable. When I hook them up to a 9V I get like a slight bump up on the crt on 10V per div. Does anyone know where I can get a probe?

    Thanks,
    Mike
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    How about a simple coax cable with alligator clips:

    [​IMG]
     
  3. Mike Nelson

    Thread Starter New Member

    Dec 30, 2014
    6
    0
    Ah cool beans. I'm in for today so I'll just use some wire? The tektronix probe has all this caps and res. stuff and idk what that does. Just learned about transistors. Thanks man!
     
  4. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
    1,147
    204
    A "typical" scope probe is x10. Some Tek scopes have a tab, that changes the V/div otherwise you have to mentally do it.

    Scope probes have what they call "compensation". You use the calibrator on the scope and adjust the "screw" somewhere on the probe so the wave is square.

    There are probes which are switchable x1/gnd/x10

    I don't even want to go into compensation for now except to say, it renders the effect of capacitance of the cables to nearly nothing.
     
  5. Mike Nelson

    Thread Starter New Member

    Dec 30, 2014
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    0
    [​IMG]http://imgur.com/uKndEeD

    Ahh that is confusing. They should call it 1/10th. Put that bit ch in there got this. Turning the adjustment screw on the probe does nothing to the signal. How inaccurate will this make my probe? + or - 10%?
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    If you have an adjustment screw AND you have a switch between X1 and X10, the screw will only have an effect on the X10 function. Doe your scope have a CAL test point? If so, it should be providing a square wave output for you to look at with the scope. In the X10 position of your probe, the adjustment will help to make the square wave appear properly. One way, it will round off the rise and fall times and the other way it will cause overshoot of the rise and fall times. Adjust until the corners are square. That is called compensating the probe to match the input of the scope.
     
  7. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
    1,147
    204
    The V/div is way to low. The intensity is way to high. The trace isn't focused either. You need a decent trace and you don't have one.

    I don't like his explanations, but the end result is OK. Which is the effect of bad compensation.

    He did a bad job of explaining how it works. In simple terms, we want to voltage divide the scope's input Z with the probes Z and not have any capacitance left over.

    An insulated piece of wire will likely give a square edge. A piece of Coax may not.
     
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