Radio Group/Antenna Planning

Exterior stair case for Roden House roof access, above bin store

At some point on the future (depending on the success of our group, presumably), it would be nice to mount some antennas on the roof of Roden House. Contributions to this plan are welcome.

• 20-40m magloop
• 2m/70cm dipole
• LoRa (868MHz) - Possible TTN gateway?

Rx only:

• ADS-B (~1GHz, I think) - Matt has shown interest in having flight tracking running from the hackspace.
• GPS/GNSS

There are a few things we would require in order to make this happen.

• Permission from the hackspace trustees
• Permission from the building owner
• Some funds to purchase or build the antennas (pledged, probably)
• Some funds to perform the installation (also pledged, probably)

Possible Plan

Shape of antenna trunking to ensure water egress. The lower u-bend should have a small hole drilled to allow water to escape

Air vent (highlighted with a green circle) which passes from Craft Room closet to the outside

(Thanks to dpslwk for a tonne of information about the building)

• Install a trunk along the outside wall (Ashley Street) between the roof and approximately the the craft room. This will make it easier to install additional coax feeds in the future. However, it's optional, and spare coax, or an antenna switcher, could be installed instead - of course this would require the coax to be neatly pinned to the wall.
• The disused electronics closet in the Craft Room (to the right of the embroidery machine) has a large air vent which goes straight through the wall.
• From this electronics closet,
  • ADS-B (if we add it) can pass into the Member's Storage so that flight tracking stuff can be hooked up easily to the network.
  • Remaining coax can pass through the floor directly into the suspended ceiling of the class room (thus proposing an area of the class room as our ham shack 😀)
• In the class room, on the wall behind the spiral stairs, drop a trucking down from the suspended ceiling to a wall-mounted coax distribution panel.

Installation of the trunking on the external wall, between the roof and craft room, would require either a scissor lift or scaffolding. If we went ahead, this would almost certainly be the bulk of our costs.

The roof can be accessed from the opposite side of the building (roughly above / to the right of Winner's Gym). There is an exterior stair case. However, we'd have to cross over the tin roof, which has not been done by a hackspace member before.

Matt has suggested he might be able to do a roof survey using his drone.

Considerations

• Maximum effective radiated power whilst in the proximity of people (10 watts). Antennas must be chosen that limit downward radiation.
• Lightning arrestors. As these may become the highest point of the building, a lightning arrestor should be installed close to each antenna. We'd need to find out if there is already a grounding strip running down the building (separate to the building's main ground), and whether this is connected to the metal roof.
• Various safety issues of working on roofs, which the hackspace insurance does not cover.

Support

To demonstrate interest and support, please add your name or hackspace username to the list below

• Aaron (Asj, talk)
• Jason (Jsmith, talk)
• JonW
• 'RepRap' Matt