If you notice that no matter what channel you tune to, your car's radio is playing more static than hits, the ignition condenser may be to blame. The condenser is a capacitor, which can hold a small amount of electric current in the ignition system. It is designed to act as a ground between the two electrodes so there is not a dangerous spark when you turn the key to start the engine.
When the condenser loses the ability to hold a charge, the sparks may get bigger and more frequent. This may lead to a buildup of an electric charge, which can disrupt the radio and cause stations that normally come in loud and clear to cut in and out and barely be recognizable. However, the radio will work fine when the car is on but the engine is not running, as the ignition will not be sparking.
Another way to tell if there is a problem with the condenser is if the engine doesn't start properly. A failing condenser could either create too large or too small of a spark, which makes it hard for the engine to turn over. It's important to note that a bad condenser will not likely prevent you from being able to start your car, it'll just give you trouble.
If you experience difficulty getting the motor to turn over, this issue could be caused by any number of damages, defects or other problems. However if it happens to be that the car has a hard time starting and the radio won't play the top 20 hits of the 90's, then the condenser could be the source of the start-up woes.
You can verify this by watching the engine run. First you'll need to remove the point cover, so you can see the condenser and the electrodes. Then, start the car and let it idle. If the condenser is faulty, you will see a noticeable yellow spark, whereas a healthy condenser will deliver a small, blue spark. Keep in mind that some engines may not run when the point cover is removed.