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I decided to add some temporary filters across the internal device after checking it - one section of this multi-section capacitor is dead, the other two sections are >80Ω ESR. (ESR is equivalent series resistance, a measurement performed at an AC frequency. Capacitors tend to increase in impedance to AC signals as they get older and wear out, high ESR means the device is dead.)

Three 10μF @ 450V capacitors were paralleled with the original, and the noise level immediately dropped to a more reaonable 0.5V peak-peak with a ripple, instead of the 11.6V peak-peak wave from yesterday's post. The original capacitor is most certainly bad, and will get replaced by the devices in the photo, once I can remove the old unit.

The device still has problems, probably other leaky capacitors. I may just rebuild the entire device and recalibrate it with new 1% parts.

https://poal.co/s/oldtechnology/742729

I decided to add some temporary filters across the internal device after checking it - one section of this multi-section capacitor is dead, the other two sections are >80Ω ESR. (ESR is equivalent series resistance, a measurement performed at an AC frequency. Capacitors tend to increase in impedance to AC signals as they get older and wear out, high ESR means the device is dead.) Three 10μF @ 450V capacitors were paralleled with the original, and the noise level immediately dropped to a more reaonable 0.5V peak-peak with a ripple, instead of the 11.6V peak-peak wave from yesterday's post. The original capacitor is most certainly bad, and will get replaced by the devices in the photo, once I can remove the old unit. The device still has problems, probably other leaky capacitors. I may just rebuild the entire device and recalibrate it with new 1% parts. https://poal.co/s/oldtechnology/742729

(post is archived)

[–] • 1 pt

LOL, I was thinking the same thing as I was looking at the photo. Those components are old and are not likely to be within tolerance anymore.

[–] • 1 pt

I could probably dial it back in with what's in there - but this thing really isn't much more complex than a signal tracer.

[–] • 1 pt

Much better. Looks like the usual suspects, which is nice. Do you use the Capacitor Wizard or a different method?

[–] • 1 pt

I have a cheap digital ESR meter that usually does the job...I'd really like to pick up a capacitor wizard but for what I do it's usually pretty obvious that they're bad.

[–] • 1 pt

Liked the ghetto method shango used for a while, with the phone and a speaker.

[–] • 1 pt

Yes, that will do you in most cases. For filters like I'm working with, you can pretty much assume they are bad.

[–] • 1 pt

Someone learned about capacitance