... . This machine select an general international standard frequency:2.4GHz , anti-jamming performance .2. Circuit (GaAs) gallium arsenide power amplifier tubes, ... distance 1500M-2KM , coupled with 24dB high gain directional parabolic antenna, distance to 10KM above.3. For select more channel, ... mutual interference between difficult channels CH 1=2414MHZ CH 2=2432MHZ CH 3=2450MHZ CH 4=2468MHZ *4 channels ...