When mounting an antenna, care should be taken to make sure it is as far away from metal objects as possible. If nearby metal gets too close to an antenna, it has the potential to interfere with the way the antenna radiates and may cause some undesirable results. In some cases, a cable must be used to connect an antenna to a transmitter or receiver. All RF cables add some loss to the system. For any given cable, the longer the cable the more signal will be lost over that cable. Because of this, the length of the cable should be kept as short as possible. Often a longer serial cable can be used to minimize the length of the antenna cable. It is important that users power off any wireless equipment before mounting or changing an antenna, otherwise it is possible to damage the transmitter. All antenna connections that are exposed to the weather need to be sealed with an outdoor coax seal tape to avoid damage to the equipment due to moisture.