My homebrew dual channel antenna switch is up and running. It let’s be switch pairs of antennas to a bunch of two channel diversity receivers.
So, I have a number of dual channel receivers, a pair of wideband receiving loops in an array, and various other antennas and receivers. Up until now, I have used a manual BNC patch pay to move antenna connections between the various radios. Time for something better.
Above, you can see my homebrew dual channel antenna switch. I made this with Sainsmart Relay modules under Arduino control.
On the right side are four antenna inputs. Each pair is connected to a single SPST relay. So, by default, one pair (the two loops) goes into the normally closed relay pins. The other pair to normally open. Each pair connects to an antenna bus, yellow and blue.
On the left, you can see the antenna outputs to the receivers. My radios are hooked into the normally open connectors, With this approach, I can activate the dual channel antenna switch either singly or in pairs. All of the logic is controlled by my Arduino Mega, at the bottom of the picture.
Later, I will write a command processor so I can control all the switching over a serial port from the radio computer. My four pairs of antenna outputs (yellow and blue) will connect to the ANAN-7000 DLE, RSPduo and Afedri dual channel respectively. The final pair can be routed to other radios or a phasing device.
Dual Channel Antenna Switch Box is 3D Printed
I printed a 7″ by 6″ enclosure, with the interior sprayed with MG Chemicals Nickel conductive paint. So, my BNC connectors all have a common ground, with the signal pins connected to the relay terminals. I used bullet terminals to wire the antenna buses to the antenna input relay outputs.
I always use lots of terminals so I can take these things apart, if needed. My Arduino provides five volts to activate relay optocouplers when a digital pin is brought low. A separate 5 VDC power supply is used for the actual relays. So, my microcontroller is isolated from the switching circuit.