This is a circuit board that enables you to make a 4 Port, relay controlled antenna switch, where the ports can be selected by a hand operated switch, or by a digital input.

The board includes surface mount components that handle the relay switching and indicator LEDs. These show that the supply power is connected, and which relay is selected.

The main use of this product is to provide antenna switching. But as the port to port isolation is >70dB, it can also safely be used to switch between transceivers (which is what I use it for) with an output up to 100 Watts, without risk to the input of the other radios.

My preference is for BNC connectors, so the board is laid out to accommodate these directly, but it would also be easy to wire in PL259s using short lengths of coax.

The board is set to accept a pair of PowerPole connectors for a 12V supply. You can of course make your own connection if needed.

The relays are switched using MOSFET transistors and the control lines are taken to an edge connector strip if digital control is needed.

The two photos show the pcb being sold here, and for reference, an earlier version fully assembled.

The parts needed to complete the board are (with suggested Mouser part numbers):

• 1 x rotary switch (if used) : 611-A10403RNCQ
• 5 x BNC sockets : 712-CONBNC001
• 4 x relays : 470-4058560000
• 2 x PowerPole Connectors (if used) : 733-58257-1095