Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 7
Situational Awareness; Troubleshooting; Confusion; Communication Breakdown
ATC Issue All Types
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Requested ATC Assistance / Clarification
ATC Equipment / Nav Facility / Buildings
I was working 3 planes on an arrival finals sector. Two pilots were answering every third transmission. After trying to descend Aircraft X for the third or fourth time without a response I said 'Hello; Aircraft X descend and maintain 6000.' Aircraft X responded to that call. Then later down the final approach course it took 3 transmissions to slow the aircraft down. I told Aircraft X that it took three transmissions and he said he only heard one transmission. This comment led me to try other aircraft and when they did not respond to try the 'orange jack'; a hand set; and mains and standbys. Finally we figured out that the frequency was failing and subsequently failed. Aircraft X had to go around.Later it became knowledge that the frequency had been going in and out and since then Tech Ops keeps saying that the frequency is fixed and to use it. The frequency will work for a while and then fail again. Please send my apology to the Aircraft X crew for being 'obnoxious' as the pilot [of another aircraft] told me on frequency. I thought they were not paying attention and it ended up being my frequency failing. The frequency should not be used again until it can be verified fixed.
The reporter reported this is a known issue and in the meantime a substitute frequency is available for use.
NCT Approach Controller reported their frequency was working intermittently even though the Tech Ops personnel reported the frequency had been fixed.