Is it a valve radio? If so then its probably a good idea to recap them, its done as a matter of course when restoring "vintage" electronic equipment, the purists not only replace the caps but hide the new ones inside the cans of the old ones.
Newer equipment, you've probably got a decade or two of life left.
Is it a valve radio? If so then its probably a good idea to recap them, its done as a matter of course when restoring "vintage" electronic equipment, the purists not only replace the caps but hide the new ones inside the cans of the old ones.
Newer equipment, you've probably got a decade or two of life left.
Hi thanks for reply,most of it is radios/decks from the 1980s.
There's no need to recap unconditionally.
A working cap is a working cap, no matter what age.
It's better to learn how to tell if a cap is defective.
Here's a couple of signs:
- Goo coming out where the legs goes into the casing.
- Bulge or signs of cracks on the top (radial) or at the negative side (axial).
- The rubber sealing at the bottom (radial) or at the posistve side (axial) is about to be pushed out from within.
There's also the possibility that caps are changing value over age, without any visible signs.
Then you need a capacitance-meter or a multimeter with such capabilities.
If the measured value is more than 5% off: Replace it.
Caps in power-supplies are more exposed to wear and tear than signal-caps.
Also, caps that are mounted close to heatsinks or in a generally hot enclosure runs more risk of changing value over time.
1980's items will be OK for a while. If you really get into this stuff, there is a vintage radio restoration forum, can't recall the URL, but they will answer any questions you have. Be warned though, its HEAVILY moderated.and extremely pedantic.
Electrolytic caps are usually the first to go but "modern" manufacturing techniques make them more reliable. As you probably know, little gets repaired these days, we throw it away and buy a new one.
1980's items will be OK for a while. If you really get into this stuff, there is a vintage radio restoration forum, can't recall the URL, but they will answer any questions you have. Be warned though, its HEAVILY moderated.and extremely pedantic.
Electrolytic caps are usually the first to go but "modern" manufacturing techniques make them more reliable. As you probably know, little gets repaired these days, we throw it away and buy a new one.
Thanks all for reply,i think i go for if its not broken dont fix it scenario,i know the site its vintage radio.net,it is indeed heavily moderated but very well run *like here of course!*
There's also the possibility that caps are changing value over age, without any visible signs.
Then you need a capacitance-meter or a multimeter with such capabilities.
If the measured value is more than 5% off: Replace it.
To measure value you'll need to desolder that capacitor... capacitor are cheaps, so if you're desoldering one (because you're not sure if it's OK) there's no reason to not change it.
I was there, too
An' you know what they said?
Well, some of it was true!
Here's an example of a defective capacitor along with a new one of the same type.
The defective one is the one to the right.
You can see that the top of it has bulged so much that it has cracked open.
Here's an example of a defective cap in a Marshall guitar amp, but this one is a bit harder to determine.
If you look at the black area between the connections, you can see a tiny little bulge in the middle there.
Just want to warn you.
This is a tantalium capacitor.
When these babies gets old, they can cause all kinds of strange behaviour.
I have repaired several amplifiers with strange noises that were caused by tantaliums.
They may come in other colors as well.
NOTE: They can be mistaken for being ceramic caps from their size and shape, but tantaliums are polarized.
This is a new MKT/MKP capacitor.
I didn't have any defective ones at hand.
These ones may not always crack or burst.
Or they may crack at the bottom, which faces down on the PCB so you can't see it without desoldering it.
Instead they often start to look pregnant when they fail.
It's best to use your fingers and feel the flat sides of it, as the bulge may be very small and difficult to spot from just looking at it.
Comments
I cover my scanner with a large drying-cloth.
EDIT: And thanks for indirectly bringing this to mind. Started a thread on it as I'm curious.
[/Hijacking_Thread]
Yes,i knew people who had equipment for years and didn't bother and still worked fine.
Newer equipment, you've probably got a decade or two of life left.
Hi thanks for reply,most of it is radios/decks from the 1980s.
A working cap is a working cap, no matter what age.
It's better to learn how to tell if a cap is defective.
Here's a couple of signs:
- Goo coming out where the legs goes into the casing.
- Bulge or signs of cracks on the top (radial) or at the negative side (axial).
- The rubber sealing at the bottom (radial) or at the posistve side (axial) is about to be pushed out from within.
There's also the possibility that caps are changing value over age, without any visible signs.
Then you need a capacitance-meter or a multimeter with such capabilities.
If the measured value is more than 5% off: Replace it.
Caps in power-supplies are more exposed to wear and tear than signal-caps.
Also, caps that are mounted close to heatsinks or in a generally hot enclosure runs more risk of changing value over time.
Electrolytic caps are usually the first to go but "modern" manufacturing techniques make them more reliable. As you probably know, little gets repaired these days, we throw it away and buy a new one.
Thanks all for reply,i think i go for if its not broken dont fix it scenario,i know the site its vintage radio.net,it is indeed heavily moderated but very well run *like here of course!*
To measure value you'll need to desolder that capacitor... capacitor are cheaps, so if you're desoldering one (because you're not sure if it's OK) there's no reason to not change it.
An' you know what they said?
Well, some of it was true!
The defective one is the one to the right.
You can see that the top of it has bulged so much that it has cracked open.
If you look at the black area between the connections, you can see a tiny little bulge in the middle there.
This is a tantalium capacitor.
When these babies gets old, they can cause all kinds of strange behaviour.
I have repaired several amplifiers with strange noises that were caused by tantaliums.
They may come in other colors as well.
NOTE: They can be mistaken for being ceramic caps from their size and shape, but tantaliums are polarized.
I didn't have any defective ones at hand.
These ones may not always crack or burst.
Or they may crack at the bottom, which faces down on the PCB so you can't see it without desoldering it.
Instead they often start to look pregnant when they fail.
It's best to use your fingers and feel the flat sides of it, as the bulge may be very small and difficult to spot from just looking at it.