Antenna switch overview

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Every shack eventually grows with more antennas than transceivers. Switching multiple antennas to a single transceivers requires some hardware. Especially when you want to do it automatically depending on the band the transceiver is operating on or from a PC. I developed some boards that help in this case:

  • Controller (available as a kit) - placed in the shack, can work with any relay board that has positive common supply to all relay coils
  • Relay board - can be placed in the shack but also outdoors to minimize the total coax length
  • Rooftop option board (reduces the amount of wiring that has to go to the roof) - placed next to the relay board

There are various ways the controller can work with the relays.

Architecture 1

The controller is placed in the shack. It works with any relay board that has up to 7 relays and relay coils share a positive common wire. Besides coaxes there is a need for a control cable with N+1 wires (where N is the number of relays).

Antenna switch architecture 1

It will not work when the relay coils have a common ground. Example:[RemoteQTH six to one switch]

Architecture 2

This architecture uses my relay board. It can switch up to 4 antennas.

Antenna switch architecture 2

Architecture 3

This architecture uses my relay board with the rooftop option module. It can switch up to 4 antennas. Only 3 wires are needed to control the relays. The rooftop option can be useful when you have a single 8-conductor Cat5e Ethernet cable going up the roof and need more spare wires to control other equipment.

Antenna switch architecture 3