Zepler Amateur Radio Antennas

A draft plan of the antennas (as of 18th December 2012).

This page details the plan to place Amateur Radio Antennas on Zepler (Building 59) in the summer of 2013, to coincide with roof access for replacement of SOWN-Zepler.

These antennas will be cabled to the Zepler Amateur Radio Equipment, probably in one of the server-rooms on the floor below. (Level 4)

Location

These antennas are intended to replace the SOWN obsolete 802.11a antenna, located on a piece of scaffolding attached to the wall of the Zepler Machine Room.

Antennas

• 6/2/70 'white-stick' collinear antenna
• 23cm yagi - possibly a G8ADM slot-feed design.
• spare slot for >=432MHz yagi or similar size

Both antennas will then be diplexed into a single coax feed before the preamp.

• Preamp - possibly a G4DDK SPF Preamp (50MHz - 4GHz)
• Bias-switched Coax Relays for TX? - Must be good through 23cm

Requires one coax cable drop with DC bias for preamp+relay power.

• Aircell 7 could be used to give better than RG-213 performance with 7.3mm diameter (Datasheet)

Rotator

This is the original mast rotator recovered from SUSU (Building 42). Following a minor repair of the feedback pot, it is in working order. However a computer-control circuit must be built for this application.

• Controller possibilities
  • 5 cable-cores required (3x AC, 2x feedback) to server-room
  • or Mast-mounted controller with PoE for single low-current cable drop?

• Ice? Do we want a remote temperature sensor to warn/disable control below a certain temperature?
  • With some thick wiring we could heat the rotator body for operation in cold conditions..