PCT Controller reported believing diverging courses existed between two aircraft; and issued a climb to one of the aircraft; discontinuing vertical separation. The courses had not diverged and separation was lost.

Narrative

I was working the combined positions of Barin; Manne; Bristow; and SFRA. The Manne Main TX and RX and the Barin TX and RX were released to maintenance. Aircraft X departed HEF. I identified the aircraft; and climbed it to 3;000. Aircraft Y was on a vector northbound for JYO airport at 4;000. I gave Aircraft X a heading of 260 and Aircraft Y a heading of 350 with the intent of establishing diverging courses. I did not exchange traffic; because in my professional opinion; the targets were not going to merge. Additionally; the Manne secondary TX failed for reasons yet to be determined; as maintenance was being performed. During my scan; I felt that diverging courses had been established; therefore I climbed Aircraft X to 10;000. Either winds aloft or Aircraft X's climb rate; or both; were not accurately considered and separation was lost. I did not exchange traffic due to the very high complexity of the situation with the radio failure and the necessary coordination required to regain communications. Additionally; Aircraft Y had already been changed to the next sector's frequency. Again; this event occurred because I believed that I had established diverging courses. My calculations were more than likely interfered with by the highly complicated situation of numerous merging targets and radio failure; and a miscalculation of the winds aloft affecting Aircraft Y's heading. Considering that frequencies for both Manne and Barin had only the secondary TX and RX; perhaps FLM's should take this into consideration when combining positions. Frequency maintenance; tones and such; has been an ongoing issue at PCT in recent months.