I want to check SWR on a waveguide but i dont have a Network Analyzer i have only 772D dual directional coupler. I use dual directional coupler, power meter or crystal detector to measure forward and reflected power and waveguide to N adapters X281aA. SWR of DUT is out of specs and i believe that the problem is the adapters i use. Can i calibrate my adapters like we do on a network analyzer? If i measure SWR only for the adapters and then with the DUT is it posible to calculate the true SWR of DUT?