A6302 Current probe analysis and modification


Twig
 

I hope this is not breaking etiquette for TekScopes, but I thought some might be interested in a recent post to another forum that describes the analysis and modification of a bad A6302 current probe. The link is https://www.eevblog.com/forum/testgear/tektronix-a6302-current-probe-analysis-and-modification/

The short version is that the bad probe was showing about 85% of the correct level at DC and low frequency.Turned out that the Hall device was detecting a nulled magnetic field with less counter-current through the probe sensing coil than normal. Very odd issue. A crude but effective modification to the probe got the response back to 100% at DC and low frequency.

The modification was to shunt the sensing coil in the probe with a small resistor (4.9 ohms). Counter-intuitive, perhaps, but it did the job.

There are a number of measurements in the linked post, including characterization of the Hall device output versus input current. Perhaps some of that information may be helpful to others who are investigating the behavior of an A6302.


 

Hi Twig,
This is not breaking protocol at all. This is exactly the opposite. It is extremely good timing for me since I just posted several P6302 questions I had and one of them is about the same sort of problem I am experiencing.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Twig
Sent: Saturday, May 22, 2021 9:52 AM
To: TekScopes@groups.io
Subject: [TekScopes] A6302 Current probe analysis and modification

I hope this is not breaking etiquette for TekScopes, but I thought some might be interested in a recent post to another forum that describes the analysis and modification of a bad A6302 current probe. The link is https://www.eevblog.com/forum/testgear/tektronix-a6302-current-probe-analysis-and-modification/

The short version is that the bad probe was showing about 85% of the correct level at DC and low frequency.Turned out that the Hall device was detecting a nulled magnetic field with less counter-current through the probe sensing coil than normal. Very odd issue. A crude but effective modification to the probe got the response back to 100% at DC and low frequency.

The modification was to shunt the sensing coil in the probe with a small resistor (4.9 ohms). Counter-intuitive, perhaps, but it did the job.

There are a number of measurements in the linked post, including characterization of the Hall device output versus input current. Perhaps some of that information may be helpful to others who are investigating the behavior of an A6302.







--
Dennis Tillman W7pF
TekScopes Moderator