Sprague 183P Question

[chicago_mike]

So I have a box full of old unused Sprague 183P capacitors. These have a stripe on one side. But they're not polarized right?

I also have a bunch of old Mallory caps , the big brown suckers, same thing, stripe on one side. GEM-601

And some Good-Alls too..again with the stripe...but I can use these in the signal path right? I know..silly newbie Q.

 

[HollowState]

...but I can use these in the signal path right?

Yes, you can. The stripe signifies the outside foil end of the capacitor. Which only means that if one side were to be grounded, that is the preferred side. Otherwise it doesn't really matter.

 

[chicago_mike]

Thanks!

 

[kevinkr]

Depending on how old these caps are I would not recommend their use where excessive leakage would result in the destruction of an output tube.

I usually throw all of these types away when I encounter them if testing indicates even a uA of leakage current with 200V or so across them. To keep unscrupulous individuals from fishing them out of my trash and selling them on eBay I now destroy them.

Some of the early Sprague poly types are fine, goodalls seem to have the occasional problem with terminations opening, and American Radionic types while good sounding have this problem in spades.

 

[chicago_mike]

Im relly just using these in preamps and di boxes. Okay really silly newbie Q. How would I test leakage?

most are unused, but yeah kinda on the old side, prolly 60's??

 

[Trout]

Yes, you can. The stripe signifies the outside foil end of the capacitor. Which only means that if one side were to be grounded, that is the preferred side. Otherwise it doesn't really matter.

According to SBE who now makes Sprague caps that is not exactly correct.

They had an article on their website that clearly stated the marking on their caps do not, nor have they ever marked the foil end. This included all Sprague film caps ever made.

I have a copy of the article someplace, but it does not seem to be on the current website.