San Bruno Mountain (Building 7)
Site located on San Bruno Mountain, next to Building 7, near the KTSF transmitter (map)(photos)
Nodes
KN6PLV-SANBRUNO-HAP
- Radio: Mikrotik hAP AC2
- Antenna: Built-in (provides onsite wifi access to mesh)
- Location: Inside the HAM Shack
- Altitude: 385m
- Bearing: N/A
KN6PLV-SANBRUNO-RAC5-1
- Radio: Ubiquiti Rocket 5AC Lite
- Antenna: 120° sector
- Location: 37.68674, -122.43525
- Altitude: 387m
- Bearing: 159° toward Millbrae
KN6PLV-SANBRUNO-RAC5-2
- Radio: Ubiquiti Rocket 5AC Lite
- Antenna: 120° sector
- Location: 37.68673, -122.43532
- Altitude: 392m
- Bearing: 207° toward Skyline College
KN6PLV-SANBRUNO-VNODE
- Radio: None
- Antenna: N/A
- Location: 37.68673, -122.43532
- Altitude: 392m
- Bearing: N/A
Backbone
Dish to Fish Ranch
- Radio: airFiber 5XHD
- Frequency: 6.025 GHz (FCC OET Experimental License WN2XRO)
- Bandwidth: 40 MHz
- Antenna: Ubiquiti RD-5G30-LW 30 dBi
- Location: 37.68678, -122.43527
- Altitude: 400m
- Bearing: 56° toward Oakland
Dish to San Carlos, Swallow, Fire Station 8 & Black Mountain (Site 4)
- Radio: UISP LTU Rocket
- Frequency: 5.965 GHz (GCC OET Experimental License WN2XUD)
- Bandwidth: 40 MHz
- Antenna: Ubiquiti RD-5G30-LW 30 dBi
- Location: 37.68678, -122.43527
- Altitude: 400m
- Bearing: 149° toward San Carlos
- Read Only Access: mesh / aredn-back-bone
Dish to Sunol Peak
- Radio: airFiber 5XHD
- Frequency: - GHz
- Bandwidth: - MHz
- Antenna: Ubiquiti RD-5G30-LW 30 dBi
- Location: 37.68678, -122.43527
- Altitude: 400m
- Bearing: 99° toward Sunol
Site Details
Tower
The tower has a 4° slope on the main lower beams. The base of the tower is approximately 23 feet wide. The first horizontal beam is 8 feet from the ground. The second beam is 7 feet above the first. The supporting angled beams, running from the group, are at an angle of 37° from vertical. The ham shack is located on the south side of the tower with a slight peeked roof. The top of the roof peek is 6 feet from the second beam. The edge of the roof is approximately level with the first beam.
The beams themselves are 3.5in horizontally, 3in vertically, and 0.25in thick with a rounded edge. The double beam which forms the second horizontal beam is 1.25in thick.
Mounting
All equipment must be mounded on galvanized supports which are themselves attached to the tower using beam clamps. All current mounting brackets should be considered unusable. Mounts using "stacked" struts are no longer allowed.
Cabling
Cabling must be run with beam camps and uv rated zip ties and cannot be directly attached to the tower. Cables run into the shack via rubber cable glands (not the plastic tube!). Cable loops are discouraged, as is excessive cable in the shack.
Power
The site provide main power (without backup) as well as 24vdc, 12vdc and -24vdc (breakers not provided) with battery backup. No solar or generator.
Originally we used the provided backup 24vdc power, but switched to our own 200Ah battery (~2 days of power) to avoid negatively impacting the rest of the site's tenants.
Configuration
-
Notes
Part of the Bay Area Backbone connecting to Fish Ranch, San Carlos, Swallow and Sunol Peak.
New Mounts
New mounts have been design using a 2" galvanized pipe attached to galvanized struts using pipe clamps. The struts are in turn attached to the tower using beam camps. The design can be found here.
All our equipment is mounted on two of these new mounts.
Future Plans
No current plans.
Completed Work
November 2025
- Dish added pointing towards Sunol Peak.
July 2025
- Fish Ranch dish moved to new pole.
June 2025
- All the equipment except the dish to Fish Ranch was moved onto a single pole facing down the Peninsula.
- A weather station was added to the pole.
May 2025
- New mounting poles were installed. Equipment needs to be moved.
August 2024
- Adjusted azimuth of RAC-1 to provide a better connection to City Hall in San Bruno. From the map, the sector is no longer centered on City Hall (it was before) but for whatever reason, this gives a more reliable connection for the same SNR. Unclear why this is. Mike has suggested moving the sector to a different spot on the tower to see if that works better.
March 2024
- Replaced Mikrotik CRS112-8P-4S-1N with Mikrotik RB5009UPr+S+in
January 2024
- Replaced RAC-2's 90° sector with 120°sector.
August 2023
- Replace Rocket M5s with Rocket 5AC Lites
July 2023
- Switched airFiber radios to support multipoint radio at Fish Ranch.
June 2023
- Based on Mike's feedback from the May visit, rerouted all our cables from the "downspout" entry into the shack to the "gland" entry point. Now all our cables go in the official way.
- Rerouted the south cabling on the tower to follow and hide behind the tower beams (per Mike) to make the install much cleaner.
- Move the NUC11 ethernet cable to the switch to allow experimenting using the NUC to manage the backbone traffic.
- Installed the new rubber entry "thingy", rerouted cables through it, and trimmed and re-terminated.
- Installed new Mikrotik Router CRS112-8P-4S-IN
- Removed UISP Router and the rack shelf it was on.
May 2023
- Non-AREDN related work at the site, but also involved tidying up cabling for various devices, including some of AREDN's ethernet.
April 2023
- Added separate power backup system using EdgePower 24V with a 200Ah LiFePo4 battery.
- Added a NUC11 (minipc) to experiment with service hosting. Idle power draw is ~4W. NUC runs Proxmox to allow virtualization of services.
March 2023
- Re-terminated the cable to KN6PLV-SANBRUNO-RM. Radio was replaced thinking the connector was broken, but looks like it was bad termination. Note that the cable to this radio is only single skinned rather than the double skinned burial grade we now use.
Hosted Services
An on-site NUC11 running Proxmox provides locally hosted services. The platform was chosen for its low idle power consumption (4 watts) and flexibility.
Services
- Mesh Map
- KN6PLV-SanBruno-VNode (virtualize AREDN node)
Meshtastic
A Meshtastic node San Bruno Mtn is mounted on the south eastern side of the tower.
Coordination
The San Bruno Mountain HAM site is own and managed by Matthew Kaufman as part of the WB6ECE Repeater Group. Coordination of changes to the site (e.g. new radios) is managed on the mailing list Sbruno_shack. Unfortunately this is an invite only group with no public archives.
Commercial Neighbors
The local WISP in this area is Etheric although they use a different tower. They license (WQTV709) spectrum from 11.2 GHz to 11.7 GHz.
Contacts
Site Admin
- Matthew Kaufman - KA6SQG - matthew@eeph.com
Mesh Admin
- Tim Wilkinson - KN6PLV - tim@sfwem.net