During a two week period late in 1997, however, the standby antennas were in constant use from 9 a.m. to about 3 p.m. for over two weeks (excluding weekends). During that time, nearby telephones became almost unusable due to a 60-cycle "sync buzz" caused primarily by the broadcasts of KTVU Channel 2. This is because RF radiation from Level 2 of the tower is projected almost directly at (and through) neighboring homes, rather than "over their heads." It would make sense that standby antennas would have to be used while the DTV mast is being installed, tested and having the kinks worked out of it, which could take a considerable amount of time. It is unknown what effect this will have on phones and other electronic devices at that time.