From: nojunk@knology.net   
      
   On 9/25/2018 9:34 AM, George Herold wrote:   
   > I was thinking of making a DC (slow) x100 'scope probe by adding a   
   > series 100 meg ohm resistor.  Any thing I should look out for?   
   >   
   > George H.   
   >   
     I built an attenuator to measure some high voltage spikes 25 or 30   
   years ago.   
     I still have it, just checked the values to put on the picture in the   
   link below. I don't recall the attenuation, It might make a 10x be a 20x   
   or a 40x. The values make me think 20x but the cap has me not sure.   
     I was able to calibrate it using the scope calibrator for a good   
   square wave, but the shield was important to allow that.   
     I was always a little concerned for the scope probe coax arcing, but   
   at 800 volts, it never did.   
   > https://www.dropbox.com/s/iwk8yzmkx766ls6/Probe%20Attenuator.jpg?dl=0   
     Note: I put a T on the scope, then the probe off one side and the   
   attenuator off the other side.   
     If I get some time I'll set it up and check the attenuation.   
      
                          Mikek   
      
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