San Bruno Mountain (Building 7)
Site located on San Bruno Mountain, next to Building 7, near the KTSF transmitter (map)(photos)
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 stainless steel 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.
Configuration
Currently the site has an Mikrotik hAP, a Ubiquiti NSM5, a Ubiquiti Rocket M5 + 120 degree sector antenna, a Ubiquiti UISP Router, and a Ubiquiti AirFiber dish pointing at Fish Ranch. All device are power either directly, or via the router, from the house 24vdc supply.
| Device | IP | Notes |
|---|---|---|
| USIP Router | DHCP | |
| airFiber 5XHD | DHCP | to Fish Ranch, Management VLAN 100 |
| UISP LTU Rocket | DHCP | to San Carlos, Management VLAN 100 |
| VLAN | Description |
|---|---|
| 1 | AREDN WAN |
| 2 | AREDN DtD |
| 13 | Fish Ranch XLINK |
| 15 | San Carlos XLINK |
| 100 | AREDN LAN |
| 911 | Emergency local management |
| Port | Description | VLANs | PoE | Notes |
|---|---|---|---|---|
| 1 | KN6PLV-SANBRUNO-HAP | 2, 13, 15, (100) | Off | hAP provides DHCP address to non-AREDN devices |
| 2 | KN6PLV-SANBRUNO-RM5-2 | 2 | 24v | Nodes are not given LAN or WAN access |
| 3 | W2GMD-SANBRUNO-RM5 | 2 | 24v | |
| 4 | (aredn) | 2 | 24v | |
| 5 | (aredn) | 2 | 24v | |
| 6 | (aredn) | 2 | 24v | |
| 7 | DISH-TO-FISHRANCH | 2, 13, 100 | 24v (4-wire) | |
| 8 | DISH-TO-SANCARLOS | 15, 100 | 24v (4-wire) | |
| 9 | Local management | (911) | - | SFP, 192.168.91.1 |
| Port | Description | VLANs | Notes |
|---|---|---|---|
| 1 | (1) | WAN | |
| 2 | 2, 13, 15, (U) | Custom config provide LAN + DtD on ports 2-5 | |
| 3 | 2, 13, 15, (U) | ||
| 4 | 2, 13, 15, (U) | ||
| 5 | KN6PLV-SANBRUNO-ROUTER | 2, 13, 15, (U) | Provides DHCP addresses to LAN devices |
Notes
Part of the Bay Area Backbone connecting to Fish Ranch.
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.
Plans
- Run a wifi scan at the proposed antenna mount point to see how noisy it is
- Reposition airFiber link to Fish Ranch for optimal signal strength (to be honest, this seems pretty good already)
Nodes
DISH-TO-FISHRANCH
Radio: airFiber 5XHD
Frequency: 5.99 GHz (Unlicensed use - FCC note)
Bandwidth: 50 MHz
Antenna: Ubiquiti RD-5G30-LW 30 dBi
Location: 37.68678, -122.43527
Altitude: 400m
Bearing: 56° toward Oakland
DISH-TO-SANCARLOS
Radio: UISP LTU Rocket
Frequency: 5.935 GHz (Unlicensed use - FCC note)
Bandwidth: 50 MHz
Antenna: Ubiquiti RD-5G30-LW 30 dBi
Location: 37.68678, -122.43527
Altitude: 400m
Bearing: 149° toward San Carlos
Read Only Access: mesh / Back-Bone
KN6PLV-SANBRUNO-HAP
Radio: Mikrotik hAP
Antenna: Built-in (unused)
Location: Inside the HAM Shack
Altitude: 385m
Bearing: N/A
W2GMD-SANBRUNO-RM5
Radio: Ubiquiti Rocket M5
Antenna: 120 degree sector
Location: 37.68674, -122.43525
Altitude: 387m
Bearing: 159° toward Millbrae
KN6PLV-SANBRUNO-RM5-2
Radio: Ubiquiti Rocket M5
Antenna: 90 degree sector
Location: 37.68673, -122.43532
Altitude: 392m
Bearing: 236° toward Colma
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
- Tim Wilkinson - KN6PLV - tim@sfwem.net
- Steve Ligtelyn - KC6SVW - steve@tcomeng.com
- Matthew Kaufman - KA6SQG - matthew@eeph.com