Axial Capacitor Replacements

Using A Radial Cap To Replace An Axial Cap

How do I use a radial cap in place of an axial?

It says on your cap listing that several of the caps "can easily replace axial" How?

I read these Q's so often that I decided to put a quick link here to point to another of my pages.

See one way it's done here.

Update 6/08:

Now the question has become why do I need to use radial caps?

High value axial caps are obsolete & have not been available for well over 10 years now. I hear people tell me they've found a source for these old dinosaurs every once in awhile & the first thing I ask them for is the coded numbers on them & 2 easy ones that have popped up a couple times are 8150 & 8610. These are straight forward dates as found on many electronic components & are the year & week of manufacture, i.e., the first one was made in the 50th week of 1981 making it 26 years old, give or take a day or two. The second one then becomes easier to see that it is newer & was made in the 10th week of 1986, but still 22 years old, which means that it could be older than the one you are replacing in your classic & quite possibly in a lower capacitance state. This would account for the many times I've heard that 1... it didn't work as well as it did before I changed the cap... and 2... it worked fine for a few hours-days-weeks & then crapped out.

Another common Q is how else can I do this substitution?

You can find a CG (Computer Grade) cap at a comparable value & add a couple wires to feed to your PCB or the better way is to use the newer, common, less expensive & more likely to be fresher, snap in capacitors of a comparable value. The wires need to be soldered to the snap in terminals & fed to the PCB. In both these cases you can look for new contact points, or even make new ones if need be, to accommodate both the new wires on one end or the other, i.e., not fishing a wire to the opposite end of the new cap. This will probably be easier with pic'd examples, so let me pick on Williams' 18,000uf20v-25v-30v axial caps.

And... here's another even larger than the one above:

And... then they got smaller before being phased out:

Let's start with the taxi cab yellow axial by removing it from the PCB.

Now you can see above that there is no close tie to the - side (ground) to wire in the + side, but looking at the + thru hole, even though there are no vacant ground thru holes, there is a wide ground strap trace running right past it. You can drill your own thru hole since there is nothing in the way on the flip side, but it's easier to just scrape & tin a spot on the trace itself. Either way, you won't need to run a wire all the way back to the original - thru hole keeping both new wires to one side.

Finish look for the quick replacement with a fresh 18,000uf35v radial of 1 3/4" length by 1 1/8" diameter. Fill in the old - thru hole & you're good to go for another 20 years. Of course, you can still run your ground wire back to the original thru hole if you wanted to, or you could drill a new one in the area where it is tapped in on the pic above.

This board has the option of 2 nearby ground thru holes to use on the + end of the cap.

Well, considering that back in the day we had to pay $12 to $20 for those dinosaur capacitors, depending on where you bought them, these new $6 investments sound pretty good to these old ears & kind of makes me want to jump back into the thick of things....wait.... let me think...not really :-)

Update June 2009:

Replacing even larger caps as found on the Midway 90421 & 90427 linear power supplies addressed here:
Stack'em Up

Happy Gaming...

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