File:2019 08 21 mt-san-bruno 69-1.jpg
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Summary[edit]
| Description |
English: These are Towers 4 and 5 (running west to east) on San Bruno Mountain, which is home to most of the Bay Area's San Francisco-based FM stations, plus a few TVs.
There are two antennas at the top of Tower 4, one top mounted and the other side-mounted (and barely visible in these shots). Both are two-bay "rototiller" style designs most typical of ERI. There are four antennas on Tower 5. Two are rototillers and two are of the kind Jampro calls "penetrator" (two horizontal V shapes, with the wide sides facing each other at an angle) Going down from the top are what appear to be: - 4 bay medium-power penetrator - 4-bay medium-power rototiller - 2-bay low-power rototiller - 4-bay low-power penetrator There are six antennas licensed: one for Tower 4 and five for Tower 5. Only Tower 4 has an ASR number: 1010564. Here is the relevant ASR info for that one: Site Elevation: 367 meters (1204 ft) Height of Structure: 76.5 meters (251 feet) Overall Height Above Ground: 81.1 meters (266 feet) Overall Height Above Mean Sea Level: 448.1 meters (1470 feet) KBLX-FM C/R Height Above Mean Sea Level: 445 meters (1460 ft) Okay, so that antenna license info looks like this: KBLX/102.9 Site Location: 37-41-21.0 N 122-26-08.0 W (NAD 27) Effective Radiated Power: 7.2 kW Transmitter Output Power: 8.3 kW Antenna Center HAAT: 387 m (1270 ft.) Antenna Center AMSL: 445 m (1460 ft.) Antenna Center HAG: 78 m (256 ft.) Calculated Site Elevation: 367 m. (1204 ft.) Height Overall*: 83 m (272 ft.) (* As Filed In This Application, may differ from ASR Data, Below.) Omni-Directional Antenna Antenna Make/Model: None ERI LPX-2E, 2 section Tower 5 is substantially shorter. So I have doubts that this listing is entirely real... KBLX/102.9 (a second main) Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 6.6 kW Transmitter Output Power: 7.6 kW Antenna Center HAAT: 393 m (1289 ft.) Antenna Center AMSL: 450 m (1476 ft.) Antenna Center HAG: 78 m (256 ft.) Site Elevation: 372 m. (1220 ft.) Height Overall: 57 m (187 ft.) Omni-Directional Antenna Antenna Make/Model: Electronics Research Inc. LPX-2E ...because the HAG is identical to the Tower 4 listing, and too high for Tower 5. But the height overall (187 feet) makes sense for Tower 5. Here are the other listings for Tower 5... KSAN/107.7 auxiliary Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 6.8 kW Antenna Center HAAT: 388 m (1273 ft.) Antenna Center AMSL: 447 m (1467 ft.) Antenna Center HAG: 78 m (256 ft.) Site Elevation: 369 m. (1211 ft.) Height Overall: 0 m Omni-Directional Antenna Antenna Make/Model: None That height above ground matches KBLX's main for Tower 4 and far exceeds the height of Tower 5. So I wonder if this one is real. Or if maybe this is the second, side-mounted antenna on Tower 4, even though the lat/lon is for Tower 5. Next down in height is— KITS/105.3 Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 15 kW Antenna Center HAAT: 366 m (1201 ft.) Antenna Center AMSL: 424 m (1391 ft.) Antenna Center HAG: 57 m (187 ft.) Site Elevation: 367 m. (1204 ft.) Height Overall: 0 m Antenna Make/Model: None This makes sense for either the top antenna on Tower 5, or the next one down, which have relatively fat lines feeding them. KSAN/107.7 auxiliary Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 8.9 kW Antenna Center HAAT: 354 m (1161 ft.) Antenna Center AMSL: 412 m (1352 ft.) Antenna Center HAG: 39 m (128 ft.) Site Elevation: 373 m. (1224 ft.) Height Overall: 57 m (187 ft.) Omni-Directional Antenna Antenna Make/Model: None This might be the second one down. KBLX/102.9 auxiliary Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 7 kW Antenna Center HAAT: 336 m (1102 ft.) Antenna Center AMSL: 394 m (1293 ft.) Antenna Center HAG: 21 m (69 ft.) Site Elevation: 373 m. (1224 ft.) Height Overall: 57 m (187 ft.) Omni-Directional Antenna Antenna Make/Model: None This is identical in height to the one above for KSAN. I presume then they are diplexed. KITS/105.3 auxiliary Site Location: 37-41-20.0 N 122-26-07.0 W (NAD 27) Effective Radiated Power: 16.5 kW Antenna Center HAAT: 329 m (1079 ft.) Antenna Center AMSL: 372 m (1220 ft.) Antenna Center HAG: 14 m (46 ft.) Site Elevation: 358 m. (1175 ft.) Height Overall: 0 m Antenna Make/Model: None This makes sense for the bottom of the four antennas, which is quite low to the ground. So I think the arrangement is this... On Tower 4... KBLX's 2-bay rototiller is the only operative antenna on top, though the second side-mounted 2-bay antenna there is a KSAN's auxiliary antenna. On Tower 5... KITS is the 4-bay top antenna. KSAN and KBLX auxiliary transmitters are diplexed through the second antenna from the top, a four-bay rototiller. KITS' aux is the 4-bay bottom antenna. The two-bay antenna, second up from the bottom, is idle. |
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| Source | https://www.flickr.com/photos/46167543@N05/48723110626/ |
| Author | Nfrastructure |
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This image was originally posted to Flickr by Nfrastructure at https://flickr.com/photos/46167543@N05/48723110626. It was reviewed on 20 April 2022 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
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| current | 17:28, 20 April 2022 | | 1,310 × 3,352 (1.91 MB) | Ser Amantio di Nicolao (talk | contribs) | Uploaded a work by Nfrastructure from https://www.flickr.com/photos/46167543@N05/48723110626/ with UploadWizard |
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