Newer units can be limited to around 50 feet. In group session, the furthest volunteer is 30 feet from the device. Radio frequencies may be detected up to 100 feet from the latest version of the RifeBare. Radio receivers on am or fm may detect some interference at distances of 100 feet. This includes CB radio detection.
Interference is greatest near the device and reduces as distance increases.
Proper tuning of the RifeBare will reduce this interference. As an operator, at least 3 feet. Any frequency used that your body needs, will affect you in some way. If you are healthy, you probably will not receive a major reaction. If you use frequencies your body does not need you will still be effected to a minor degree from the electomagnetic field produced.