Buzzing / Static in your factory radio? Quick fix!
Posted: April 5, 2012, 9:39 pm
So you've got an original factory radio in your truck. Looks great- But doesn't SOUND great. Probably a lot of static and buzzing- More than you should experience from your old AM radio. There are a lot of potential sources- Especially when the engine is running- But, a lot of the problem can be remedied with a simple fix- Replacing the old, dried out capacitors with fresh new ones.
Your radio uses several electrolytic capacitors in it. Without going in to a lot of detail, an electrolytic capacitor relies on a fluid electrolyte to operate properly, and over time they can dry out. Your radio is more than 40 years old- and the odds are the capacitors are not operating like they once were. So- It's time to replace them.
There are a number of capacitors on the inside of your radio, but there are only TWO that we are really worried about-
One is a 50µF, the other is a larger 500µF. Both are indicated in the photo above. These are the only two electrolytic caps on the board. The other capacitors we won't have to worry about
Now, the values on the two capacitors in the radio are 50µF and 500µF (µF is MICRO FARAD, a unit of capacitance, if you're wondering). You probably won't be able to find them- But you can get close. Find a 47µF and a 470µF radial (you COULD use an axial, but the radial ones will be easier to install!) capacitor- rated at 35 volts, and you're good to go. It's close enough for our application. You can get them at Radio Shack for about $1.50 each-
Or, you can get them (and all the other parts you'll need) from this place- http://www.allelectronics.com/index.php . They are actually a lot cheaper from them, other than having to pay shipping. These capacitors will be a LOT smaller than the ones that you are replacing- But don't worry- That's just progress. Think of how many other things have shrunk in size since the '60s!
All you have to do is remove the old capacitors, and solder in the new ones. It's a bit tight inside the case, and the wires are not long enough to allow removal of the circuit board, so to make life easier, here are the locations of the caps on the back side of the board, where you'll be working-
Desolder the old, and replace with the new. One IMPORTANT thing to remember- Capacitors are polarized, meaning that there is a negative and a positive side to them. They will be labeled, and usually the post on the negative side will be shorter as well. Just make sure that they are installed properly- The photo shows the correct way. With both of them, the NEGATIVE was up.
Once you've installed the new capacitors, power up the radio, and (hopefully) enjoy the new, Clear sound... Or, at least clearER sound. It is an AM radio, After all... Part of the charm is the terrible reception!
-Andrew
Your radio uses several electrolytic capacitors in it. Without going in to a lot of detail, an electrolytic capacitor relies on a fluid electrolyte to operate properly, and over time they can dry out. Your radio is more than 40 years old- and the odds are the capacitors are not operating like they once were. So- It's time to replace them.
There are a number of capacitors on the inside of your radio, but there are only TWO that we are really worried about-
One is a 50µF, the other is a larger 500µF. Both are indicated in the photo above. These are the only two electrolytic caps on the board. The other capacitors we won't have to worry about
Now, the values on the two capacitors in the radio are 50µF and 500µF (µF is MICRO FARAD, a unit of capacitance, if you're wondering). You probably won't be able to find them- But you can get close. Find a 47µF and a 470µF radial (you COULD use an axial, but the radial ones will be easier to install!) capacitor- rated at 35 volts, and you're good to go. It's close enough for our application. You can get them at Radio Shack for about $1.50 each-
Or, you can get them (and all the other parts you'll need) from this place- http://www.allelectronics.com/index.php . They are actually a lot cheaper from them, other than having to pay shipping. These capacitors will be a LOT smaller than the ones that you are replacing- But don't worry- That's just progress. Think of how many other things have shrunk in size since the '60s!
All you have to do is remove the old capacitors, and solder in the new ones. It's a bit tight inside the case, and the wires are not long enough to allow removal of the circuit board, so to make life easier, here are the locations of the caps on the back side of the board, where you'll be working-
Desolder the old, and replace with the new. One IMPORTANT thing to remember- Capacitors are polarized, meaning that there is a negative and a positive side to them. They will be labeled, and usually the post on the negative side will be shorter as well. Just make sure that they are installed properly- The photo shows the correct way. With both of them, the NEGATIVE was up.
Once you've installed the new capacitors, power up the radio, and (hopefully) enjoy the new, Clear sound... Or, at least clearER sound. It is an AM radio, After all... Part of the charm is the terrible reception!
-Andrew