Customer’s concern: “My radio isn’t working right. It fades in and out and has static.”

What’s happening and why: Many “radio reception” problems are not really the fault of the radio but rather the result of peculiar radio phenomena or antenna interference. Moreover, each type of broadcast signal–amplitude modulation (AM) or frequency modulation (FM)–has different characteristics and is affected by different conditions:

• The low-frequency AM signal travels by bouncing back and forth between the ground and the upper atmosphere in a zigzag pattern. This pattern causes the signal to travel farther and have stronger reception (come in more consistently at greater distances) than FM. The main problem affecting AM signals is electrical interference. Also, the bouncing pattern causes AM signals to fade under bridges or in tunnels.

• The high-frequency FM signal is limited to a smaller reception radius, around 50 miles. The FM signal travels in a straight line and loses strength when it can’t be broadcast straight to the antenna; for example, when blocked by buildings, hills, or large trucks. This causes increased hiss or fading and interruption in the FM signal.

What can be done: Some things your Acura service technician can do will help with problems in both AM and FM reception, while other things affect either AM or FM:

• Problems With Both AM and FM. First, if the problem

is distorted sound, static, or no sound from one speaker, play a cassette or CD in the player to make sure you’re not mistaking a speaker problem for a “radio reception” problem. If the cassette or CD sounds good and the music comes out of both speakers, then at least you’ve ruled out the speakers and the amplifier as the source of the problem.

• AM Problems. For AM signals, an important factor for good reception is a good antenna ground. If static is the same on all stations, the problem is probably a bad ground at the antenna, a faulty antenna lead (coaxial cable), or loose connection of the coaxial cable to the radio.