Never operate two transmitters on the same frequency at the same time in the same location.
Use the scan function to find frequencies that are clear at the location where the system will be used.
After initial system set up, conduct a walk test throughout the performance area.
Experiment with different system set-ups and receiving antenna locations.
During a performance if a receiver is on, keep its corresponding transmitter on. All transmitters in a system turned on will often mask minor incompatibilities. Alternately, if the transmitter is off, make sure that the receiver is muted at the mixing console.