Directional coupler with incident and reflected wave detectors
TD-10/100/1000

price: 200$

* It cuts a transmitter when a set value of antenna path VSWR resultant   value is exceeded (transmitter-cable-antenna):
    - for 10 W - VSWR=1,5...3,0
    - for 100 W - VSWR=1,5...2,0
    - for 1000 W - VSWR=1,2...1,6

Product specifications
Coupler directionality 27-30 dB
Frequency range 100-1000 MHz
Supply 15-36V / 20mA
Output (open-collector) Umax=36V
Imax=20mA