Tower Site Pictures KFBK Transmitter 2-6-8923 photos Sylvan Tower Site, Portland, OR 89.1 KMHD backup transmitter, formerly a couple cabinets of the KOIN 6 main transmitter. FM+HD at -14 dBc. Sylvan UHF TV combiner. Channels 24, 25, and 33. KATU 2 transmitter. Virtual channel 2. Transmit channel 24. Water cooled Rohde & Schwartz.