RF SIGNAL
Wireless systems use RF (radio frequencies) to transmit the audio signal from the body pack transmitter to the receiver. And just like the radio in your car, if you get too far from the transmitting tower, or you have objects between you and the tower, you get interference. To let you know if the RF signal is being interrupted or getting weak, your wireless system will have an “RF" meter on the receiver (see your manual). It’s important that you pay close attention to this meter when you are preparing to shoot. It’s informing you if the RF signal is being compromised in any way. If the RF signal is low or is fluctuating, you will need to remedy this before you start shooting. If you don’t, you’re going to get burned.
A few tips that will help stabilize the RF signal and decrease RF hits:
o Never cross the transmitter’s antenna with the cable from the lavaliere microphone. This will greatly reduce the range and stability of your system. See Figure 8.1.
o Keep the transmitter’s antenna off the talents skin. Moisture from a sweating actor or actress can cause hits if the antenna gets damp.
o Never bend either the receiver or transmitter antenna. Keep them straight and free from bumping and jostling wherever possible.
o A wireless system is more stable at close range so the closer you are to the talent wearing the transmitter, the more stable the RF signal will be. If your mixing position is causing RF problems, use an XLR cable to move the receiver closer to talent for better reception. Look at the RF meter on the receiver to choose its best placement.
o Clear line of sight between transmitter and receiver will increase the system’s distance, so the fewer walls, cars, people, and articles of clothing you have between you and the talent, the further away you can be.
o Whenever possible, have the transmitter and antenna exposed. If you will not be seeing the talent’s back, place the transmitter on the outside of the clothing.
o Always use fresh batteries. As the battery life decreases in your system, so does the systems range and stability. I will not use batteries that are below 90% of their full charge in a wireless system. For example, a 9V battery fully charged is around 9.52V. I will replace it when it drops below 8.2V.
o If the receiver is strapped into my mixer’s carrying case, sometimes just moving my body or the receiver’s antenna can help reception. I call it the RF dance because of the funny positions I find myself in trying to increase the RF signal strength.
Excerpt from LocationAudioSimplified - Chapter 8: Wireless Systems
Excerpt from LocationAudioSimplified - Chapter 8: Wireless Systems
Figure 8.1
Transmitter extended closer to talent with 15' XLR cable.
