Any ideas as to what kind of capacitors these are?

xbart

xbart

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I've been slowly working my way through a large lot of old components I came across and now trying to ID these.
They have no identifying marks other than the green and black marks seen.
They all measure .0018 uF, they are the diameter of a quarter.
They are shaped a bit like a ceramic cap, but have axial leads and are a lot thicker than any ceramic caps that I've come across.

Any ideas?
-Brad
 

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x2 on that. I think they are a European style, but could also be early 1960's Japanese production as well. Probably Mica.
 
Hyperion said:
This type of capacitor often used in CRT TV or CRT Oscilloscope voltage multipliers.
Click to expand...

That may be, but I have never seen that style in any of the scopes I have torn apart over the years. (A TV or two- yes- though rare) But as those things go, I will probably see lots of them now in the coming weeks.
 
Put a few kV through one and see what it takes to blow it up. :D

Wonder what the dot code is? Doesn't seem to have enough colors (2 dots plus the red case) to pin it down.
 
Never seen one of those, and I've seen a lot of parts. Red MOVs are common and have some residual capacitance, but that lead style isn't really right for MOVs, and they're usually well marked. Do they have any leakage resistance? I'm going to go with very HV caps too.
 
I had a 25kV neon plant bombarding transformer, controlled by a large iron slide choke. The limiting device was a Jacob's Ladder, try to run too much juice through a tube being evacuated/bombarded and the spark would jump the Jacob's Ladder.
 
Thanks for all the replies, I got a lot of odd stuff and half the fun is trying to figure out what it is!

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Anyone up for another question about precision resistors and where they are used.
Here is a couple examples of the resistors in question, a lot have very low Ohm values like the 1.6 Ohms as seen here.
I have some that are the size of a C battery.
My limited experience is mostly with replacing worn parts in vintage tube gear.
I never have come across Ohm values like these, so where and what kind of application would they be used?
 

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Who knows. Could have been robotics, radios, military stuff, aerospace, you name it. Expensive stuff if you need it, but no matter how many you collect, you never seem to have just the right thing. :D Of course, you keep them anyway.
 
Precision attenuators? shunts and/or voltage dividers for metering devices?

Useful? maybe...

I have a 1Kohm 0.01% resistor that I use to check the calibration on my multimeter ohms range. :smoke:
 
Those are very nice and probably very stable. You might have enough values to build a measurement bridge or something. They might be wire-wound, so not suitable for high frequency use.
 
I think the ultraohms are stacked type of construction. I have damaged a few of those over the years.

1.6 ohms is useful for power transistor circuits to equalize any differences that may exist in conductive properties in quantities of power transistors.

If you have enough large power resistors, you could always do the pocket pre on steroids. Where it calls for 1/8 watt 100 ohm resistor throw in a 100 Ohm 100 Watt resistor......:D

In the days of room sized personal computers, and hangar sized mainframes, they used a lot of current, and the power supplies were always being tweeked to make them somehow better. As a result, many things went obsolete overnight and a lot of that dead stock went out the door to salvage wholesalers. Anyone remember "Poly Paks"?
 
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