EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: ktulu on May 06, 2015, 03:57:07 pm
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I have a Hameg X10 oscilloscope probe, and a 25MHz bw analoge scope.
(and a 10MHz scope also)
I am unable to compensate the probe using the built in variable cap. It is under compensated, and has some high overshoot aswell. (see attachment, it shows the two extremes I can adjust)
I was trying to pull the probe apart (to maybe change the cap) without success.
There is a second adjustment hole that hides another little pot. (i guess for high frequency compensation?)
Unfortunately there is no model number, or bandwith written onto the probe, only HAMEG a few times on the cable itself.
I don't belive it is such a high bw probe, that the compensation rage is not enough for my 25MHz scope. (the adjustments are in the tip, not the scope end)
What could be wrong? Is there any way to correct this so I can use the probe?
Thanks.
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I have a Hameg X10 oscilloscope probe, and a 25MHz bw analoge scope.
(and a 10MHz scope also)
I am unable to compensate the probe using the built in variable cap. It is under compensated, and has some high overshoot aswell. (see attachment, it shows the two extremes I can adjust)
I was trying to pull the probe apart (to maybe change the cap) without success.
There is a second adjustment hole that hides another little pot. (i guess for high frequency compensation?)
Unfortunately there is no model number, or bandwith written onto the probe, only HAMEG a few times on the cable itself.
I don't belive it is such a high bw probe, that the compensation rage is not enough for my 25MHz scope. (the adjustments are in the tip, not the scope end)
What could be wrong? Is there any way to correct this so I can use the probe?
Thanks.
Looking at your photos, I would say you could as somewhere between these extremes would be right.
However some probes DO NOT have the range of adjustment to compensate on some scopes.
Only the datasheet for the probe and knowledge of the scope input capacitance can confirm they will match.
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Like in picture 336 is the best I can get. Turning the pot either way, it gets under compensated. (going towards the other picture)
Only if someone here recognizes the probe, and provides a model number, I can search for data sheet.
The scope has a max input capacitance of 36pF according to the manual.
Weird is, I also have an Agilent 10074C 150MHz probe, and I am able to just get it compensated. It is right on the edge.
What about the weird overshoots on the rising and falling edges?
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Are you using the scope's 1 KHz Cal output?
Try a cable connection just to be sure its not the problem.
Just twist it around the Cal terminal and poke the other end into the BNC. GND not required for this check.
Many use P6100 1:1, 10:1 probes, cheap and fine for all normal use.
http://www.ebay.com/itm/Two-P6100-DC-100MHZ-Oscilloscope-Scope-Clip-Probe-100MHz-For-Tektronix-HP-GA-/181607249293?pt=LH_DefaultDomain_15&hash=item2a48a2b58d (http://www.ebay.com/itm/Two-P6100-DC-100MHZ-Oscilloscope-Scope-Clip-Probe-100MHz-For-Tektronix-HP-GA-/181607249293?pt=LH_DefaultDomain_15&hash=item2a48a2b58d)
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Yes I am using the cal output, which is a perfect square connected directly.
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Yes I am using the cal output, which is a perfect square connected directly.
Time for new probes. ;)