Military
Air Traffic Control Fully Certified
Communication Breakdown; Distraction; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
I was working Sector 35 and had just taken Sector 34 back (combined positions). SPS Approach launched Aircraft X and one other [same type aircraft] on a cross country flight around the same time. I climbed both aircraft to FL230; pointed them both out to Sector 48; both were acknowledged; flashed the aircraft at Sector 48 and shipped the front aircraft. I thought I had flashed Aircraft X to Sector 48 but I actually hadn't. I shipped Aircraft X to them and they climbed the aircraft to FL250 without verifying his position. Aircraft X began a climb to FL250 with Aircraft Y descending out of FL260 for FL250. Both aircraft received a TCAS RA. During this time; I was trying to become acquainted to the new airspace I had just taken over and was quickly becoming overwhelmed because my OKC-L (sector 35) UHF frequency was only working intermittently. During that session; several aircraft had to be called 3-5 times before they acknowledged my clearance or instruction. It was quite distracting.  After this event; I reported the frequency issues to the COM. I was told it was atmospheric conditions and nothing could be done to fix it. Several aircraft on both OKC-L UHF and SPS-L UHF complained about excessive static and not being able to hear me on frequencies that day. Additionally; I was working several [same type aircraft as Aircraft X] in and out of the Westover MOAs. All these aircraft; while all UHF; were on different frequencies and stepping on one another (which is normal). The traffic was both moderately busy and fairly complex. The sectors probably needed to remain split for about 5-10 minutes more when we combined them; but there was significant pressure on all parties to combine positions as soon as possible due to low staffing for COVID-19 social distancing procedures.Improve frequency reception on these 2 sectors. There is a dead spot just south of the Washita MOA that UHF aircraft usually can't hear us on [Sector] 35's UHF frequency. The frequencies should work despite if there are 'atmospheric conditions' or not. The frequencies not working correctly and no alternates was very distracting.If SPS Approach were to space these cross countries out a bit I could see that being beneficial. Or have the Westover departures depart at a different time than the cross countries. They all go out and all come back at the same time; it's a mad rush to get everyone climbing and out to the MOA's/higher on their cross countries; then we have extended periods of nothing going on at all.
ZFW Center Controller working combined sectors reported an airborne conflict and cited workload and staffing issues as contributing factors.