Why Do People Put Tennis Balls On Car Antennas?

If you've ever looked at a vehicle in someone's garage or a truck driving down the highway with a tennis ball on the antenna and wondered why, there are actually some very good reasons for it. For most people, sticking a tennis ball on top of their antenna is an easy way to help determine how far into their garage they need to drive. The tennis ball will make contact with an area, whether a low roof or a shelf, that signifies to the driver they should stop.

You may also see a tennis ball on a large truck's antenna, although that is for an entirely different reason. Many shipping trucks have CB Radios and large whip antennas. Since those antennas can be quite long and move around during normal driving, truckers will add tennis balls to them to keep the antenna from scratching the truck.

In most modern vehicles, drivers and passengers don't even see or notice the vehicle's antenna. Instead of a long stiff wire near the windshield, vehicles now have small and powerful antennas on their roofs. These modern antennas are almost seamlessly designed into the roof of the vehicle to make the vehicle look nice and help with aerodynamics.

CB radio antennas are big and flexible, meaning they sway during normal driving and can cause some significant damage to the exterior and windshield of a vehicle. Nobody wants damage to their vehicles, so truckers and those who have added CB radios to their personal vehicles will place tennis balls on top of the antenna to stop any significant damage from happening.

One unique issue this raises is when a tennis ball is added to the antenna, it actually changes the frequency in which the antenna sends and receives signals. If you have a tuned antenna that's set to your preferences and then have added a tennis ball for safety, you'll have to retune your antenna.

The longer and higher in the air your CB radio antenna is, the better the performance you'll have. However, the longer your antenna is, the more likely it will hit the vehicle and the need for a tennis ball on top is necessary.

Placing a tennis ball on your antenna isn't the only way you can use one for a vehicle. As was mentioned in the first slide, drivers can place tennis balls on strings in their garages to help show them where they need to stop the vehicle. The tennis ball hangs on a string from the ceiling and hits the windshield when the vehicle is in its proper spot.

One major myth when it comes to tennis balls and vehicles is that drivers will be able to unlock their car if they've locked their keys inside and are unable to enter. By placing a small, screwdriver sized hole in the tennis ball, placing the hole on the car door lock, and squeezing the ball with all your strength to push air into the lock, some claim that the air pressure will release the lock. Unfortunately, this is completely untrue and has been found to not work by real mechanics.

It's also not uncommon to see tennis balls placed on trailer hitches. This is so, if someone is rear ended, the trailer hitch doesn't cause more significant damage to both vehicles. It also helps keep the hitch from rusting during winter weather.