In this paper, the computation of dual knife edge diffraction loss by Deygout multiple knife edge diffraction loss method is presented for a 6 GHz C-band microwave link. Also, the computation of equivalent single knife edge obstruction that will replace the dual obstruction by giving the same diffraction loss as the dual obstructions is presented. The results shows that for the dual obstructions M1 and M2 the total diffraction loss is 54.57746 dB as computed by the Deygout method. The individual diffraction loss from obstructions M1 and M2 are 32.85901 dB and 21.71845 dB respectively. Furthermore, a single knife edge obstruction located at the middle of the link (a distance of 1275m from the transmitter and receiver) and with line of sight clearance height of 483.5089m will be give the same diffraction loss as the dual knife edge obstructions M1 and M2. Essentially, the line of sight clearance height of the equivalent single knife edge obstruction are much more than the sum of the line of sight clearance height of the two initial obstructions
