How far can a UHF-R transmitter (U.S. version), set to high power, be from the UHF-R receiver?
Here are test results from Shure Engineering:
UR1 bodypack transmitter at 100 mW setting: 3,100 feet maximum
UR2 handheld transmitter at 50 mW setting: 2,500 feet maximum
The test was made with 1/2 wave, passive antennas; outdoors; clear line-of-sight from transmitter to receiver. These distances can vary dramatically based on local RF conditions. Shure does not guarantee the transmission distances listed above.