[Collins] Cap questions.

[Dr.Gerald Johnson]

HIgh Ripple current rated capacitors are better. They can stand high 
ripple currents without excessive heating or excessive ripple voltage. 

Snap mount don't fit the metal can mountings. They snap into PC 
boards designed to hold them. The name for the metal cans are "twist 
lock."

Doubling the capacitor size increases inrush and increases the peak 
current each half cycle. Both are limited mostly by transformer 
impedance.  Both stress the rectifiers.

All electrolytics, large and small need replacing. All Black Beauties 
need replacing. Its possible for some other capacitors to need 
replacing, but only circuit troubleshooting can find those. Mica and 
disc ceramic capacitors aren't entirely failure free, but don't fail 100% 
like old electrolytics and black beauties.

I think it works nicest to use a narrow lathe tool to cut the top loose 
from the electrolytic can, then take out the guts (corrosive), and wire 
in the new capacitors. Reattach the top of the can with silver or 
aluminum colored epoxy in a small bead. Make that cut right above 
the shoulder of the base. Think of stacks of 6 or 7 as well as three 
capacitors to fit in the can.

73, Jerry, K0CQ, Technical Advisor to the CRA

-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.