Quote:
Originally Posted by jr_tech
Do you have a schematic?
http://bama.edebris.com/manuals/b&k/1460/
I would check supply voltages to see if anything drops as the scope fails. If the scope is connected to its internal calibrator, does that voltage appear to drop? |
Well I do now, thanks. I have a pdf of the user manual - sans schematic. I'll have to do some testing to find out about the internal calibrator.
Quote:
Originally Posted by old_tv_nut
Agree: check supply voltages.
Is it changing sweep width or brightness? I gather only vertical?
Also, can you determine if it drops suddenly or gradually? If suddenly, could be something intermittent in the vertical sensitivity adjustment. 2:1 change sounds suspicious.
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Only vertical, no other noticeable changes. Definitely a gradual decrease, however, it occurs rather quickly, over perhaps 10 seconds. So it'll be fine for 15 minutes, lose vertical in span of 10 sec, but never lose it entirely.
Also, yes it is a 2:1 change, but not perfectly - when it's failing, you can observe the vertical slowly fluctuating bigger and smaller, just a little.
Quote:
Originally Posted by N2IXK
Another vote for checking the power supplies. The unit is old enough to consider a "shotgun" replacement of electrolytics, especially if you rely on the unit for income generating work.
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Yeah, I'm all for the shotgun method, I'm just trying to figure if this sounds like a capacitor related issue. Yet, part of my wonders if this is a transistor issue.
Quote:
Originally Posted by init4fun
get one of those apps that make your cellphone display the scope images and leave the antique stuff to be used working on the other antique stuff in your collection.
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lol 'antique.' You funny guy. My 1950s Simpson O-scope is my antique, this BK is my 'daily driver.' So to speak, I probably only use it once a month, but yes, for actual income generating work. Also - I've yet to see any professional smartphone o-scope thingies. They all seem to be project-type crap for fun and screwing around... when I use an O-scope, it's a
tool. I'm not saying they won't work, I'm just saying I've yet to see one that's not just an exposed circuit board, or isn't way more than the $70 I spent on this scope. :/