EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: dorkshoei on October 13, 2014, 06:24:55 pm
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Does anyone have one of these? The original BR28, not the PR28A.
Basically this: http://www.test-and-measurement.net/bk-pr28.htm (http://www.test-and-measurement.net/bk-pr28.htm)
I came to use mine today for first time in probably 10 years and I found a note inside the storage box saying that it had stopped working which reminded me that it had.
I remembered it just stopped working while I was using it and I recalled taking it apart at the time I wrote that note but couldn't recall what I discovered.
Anyhow I just took it apart again and put it back together and now it's "working" but I'm reading 19Kv rather than the spec'd 21Kv. I need to borrow another probe to check calibration.
My question.
Has anyone ever taken theirs apart?
Inside there is a HV resistor (600Mohm) and also a spring. I expect this is what the manual refers to as "spring, resistor 767-037-9-001". On one end of the resistor is a screw+washer and the other end nothing. The spring isn't attached to the resistor in any way, at least not on mine. The spring is conical and has a small nut and star washer pressed onto the end.
I'm not 100% sure what the correct orientation is. I think it's as shown but I wasn't sure if anyone knew for sure? The zoomed in picture is the interior of the plastic probe tip, where the spring makes contact.
I called BK, a) it's too old b) they don't give info out on questions like this