Environmental Considerations UniMas San Francisco LLC KFSF-DT Vallejo, CA Ch 34 850 kW 498 m
KFSF-DT operates from the Sutro Tower facility in San Francisco, also used by most FM and television stations serving the San Francisco area. This hilltop site is protected by fencing and fulltime security guards. Access to the site is restricted to authorized personnel and visitors only, with the gate under the guard’s control. Appropriate radiofrequency energy (RFE) advisory signs are posted. In 2011, Hammett & Edison prepared a study of RFE levels throughout the site, relying on measured values at and near ground level and calculated levels at elevated locations on the tower. That study is attached hereto. It is used to regulate work on the structure.
Operation will continue on channel 34, centered on 593 MHz, at which the radiofrequency energy exposure guideline value of 395 µW/cm2 for the general population. The Dielectric TFU- 26DSC/VP-R P190 antenna has its radiation center 269.5 meters above ground level. Based on the theoretical elevation radiation pattern attached, the maximum radiation value toward the ground may be presumed not to exceed 0.09. The vertically polarized ERP is 16% of the horizontal. Consequently, the worst-case exposure level at 2 meters above ground level is predicted to be 3.73 µW/cm2, which is 0.94% of the protection guideline value for uncontrolled environments.
An exposure survey of the KFSF-DT transmitter suite was reported in the station’s most recent license renewal application. The spatial maximum measured RFE level did not exceed 9.2% of the maximum permissible level for uncontrolled environments within the KFSF transmitter room, office space, and transformer vault. Extrapolating from the licensed 370 kW to the proposed 850 kW level, the spatial maximum RFE level should not exceed 25% of the maximum permissible level for uncontrolled environments within the transmitter suite.
29 November 2017
Karl D. Lahm, P.E. California Registration #E10307 Director, RF Systems Engineering Univision Management Co. P.O. Box 647 Lake Villa, IL 60046