Quote:
Originally Posted by darklife
Thanks for the replies so far. I will look around my junk boxes and see if I can find an old transformer that will work as a "bucking transformer". I just don't feel comfortable with how warm the power transformer runs but I don't know maybe it was made to handle that much heat. It gets almost too hot to touch after an hour of operation while inside the cabinet.
Another problem I notice is that on a few of the sweep selector ranges the waveform gets more narrow toward the left of the CRT, and wider toward the right. Just enough to be noticeable to the eye. I wonder if the sweep oscillator needs a tuneup or maybe has an old capacitor that is acting funny?
It only seems to happen on the 1-10k range.
I don't really have any other projects going for me right now so I plan on tinkering around with this until it works really good. Do a few modifications to make it run better and recap it so it runs as new. Besides this is teaching me a lot about the internals of how an oscilloscope operates so it's an educational project for me.
Any further ideas or suggestions are appreciated.
|
There are thousands of these out there working on the higher line voltage with no problems.
Definitely do the recap - the B+ filter caps, even with the slightest leakage could cause the tranny to get hot. Even a few milliamps of leakage at 375 Volts could equal several watts. I fired off my 460 this afternoon - it hasn't run in about a year and a half, and it woke up fine. The tranny was barely warm after 20 minutes. I put her back together a hour or so later, and the tranny was just warm, not hot. I'd replace the 20/20/20 @450 with some 22uF@450 caps and see if that cools it down some.
Cheers,