No Aircraft
Air Traffic Control Fully Certified
Communication Breakdown; Troubleshooting
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
ATC Equipment / Nav Facility / Buildings
While working various positions in the Tower cab; it became apparent there was an issue with the shout line to NCT. Every position reported calls sounded near muted level quiet with static on the line. This made routine coordination extremely difficult as PAO had to ask for the NCT controller to repeat themselves several times before the message was understood. NCT did not appear to have any difficulty hearing PAO controllers. PAO uses a very old communications panel that has been seeing an increasing number of issues recently. This is the second time in a one week period that there has been difficulty communicating with NCT via a shout line; although the problems were not identical to each other. A new communication panel should be more reliable and result in fewer interruptions. Permission granted to share a de-identified copy of this report.
PAO Tower Controller reported that an unreliable; aged; failure prone communications panel is unsafe for use.