B737-700
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 424; Flight Crew Type 18000
Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown
Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Human Factors; Procedure
We were on final approach to Runway XXL in ZZZ and were told to 'contact Tower now;' without being given a frequency. Normally; when we switch frequencies; we are given the frequency to switch to. We switched to the Tower and were cleared to land; and told we were number one for [Runway] XXL. As we were about to start down on the glideslope; we were told to cancel our approach and to climb and maintain 5;000 feet and track the localizer; by the final monitor; which was selected on radio two. The First Officer immediately acknowledged the clearance; and I turned off the autopilot; and began a climb to 5;000 feet and tracked the LOC outbound. The final monitor repeated his instructions and demanded we reply. The First Officer switched to the monitor frequency to ensure he heard us and told him we were complying. Afterward; there was discussion on why he didn't hear our response; and we found that we had the wrong Tower frequency programmed for the runway in use; so the final monitor couldn't hear us. We were confused; because we had checked in with the Tower and they cleared us to land; so we couldn't understand why the monitor couldn't hear us.When told to call the Tower; the controllers should also state the frequency; especially when doing PRM (Precision Runway Monitor) approaches. We should have done a better job of verifying the frequency in the high workload environment.
B737-700 flight crew reported on incorrect frequency on approach resulting in go-around.