Well the problem is coming back again. The first .1mfd 1600v capacitor before the filter resistor is starting to make that arcing sound. At least I think it's coming from the cap. It sounds like a few snapping sounds when I first turn on the scope.
When this happened before it wasn't long after that the capacitor shorted out causing the PS fuse to blow.
I know there shouldn't be no >1600v on those capacitors, yet they keep doing this. First it was the wax cap that went bad (yes I know wax caps are bad anyways), then a black plastic one rated at 1600v which I replaced. The schematic calls for 1000v cap for filter,... so WHY does these 1600v ones keep snapping and then shorting on me?
How do I measure the HV on this? My multimeter only measures up to 1000DC and I really don't trust my meter for this kind of stuff.
I would like to measure the HV output to see if it's really above what the capacitors can handle.
I also notice that the scope goes to blooming trace on anything above half way up on the intensity control. So it's getting a lot of HV is my guess.
The scope is working fine still but I know it's days are limited until I figure this out. It's only a matter of time before it eats another HV capacitor which lucky me I am now completely out of replacement parts for.
As soon as I heard that internal snapping sound in the past it wasn't long after that the HV capacitor shorted. I don't see any physical arcing and I swear the arc sounds like it comes from inside the capacitor.
These capacitors are new BTW.
Also finding HV capacitors are not easy today. Is there any practical way to string up higher mfd capacitors at lower voltage to equal .1mfd to get to the voltage/filtering value it needs?
Like taking -----)|---)|---)|-----
Each one being rated 600v to total a 1800v handling capability?
Excuse my ascii, but something like that?
I believe high value resistors would need to be wired in parallel with each cap to equal out the voltage across each capacitor correct?
I know in transmitters the HV supply for the power amplifier tube is sometimes wired that way for HV filtering.
Ugh sorry for the long post and questions. You guys rock for info.
I should just get myself a good oscilloscope and toss this thing into the corner but right now this is all I have to work with
