Years ago I inherited two Loral Coax switches from a friend. I have been trying to find a good use for them for a while now. Like so many older pieces of equipment, there is not a lot of documentation available for it. Thankfully after spending some time searching the internet, I was able to develop a pretty good idea of how it functions.
The device itself utilizes a DB9 male plug on one end and five SMA type female connectors on the other end.
I created a schematic to streamline the pin assignment identification for the DB9. The switch requires 24VDC for operation and utilizes a 0-5VDC range to control the logic for each switch.
Having successfully ensured the device functions as intended, I’m now considering a project for its application. While online data suggests its compatibility with transmissions, I intend to utilize it specifically for switching receive antennas.
As for a use… The basic idea is to remote mount a RaspberryPi and the switch close to an antenna array. Providing it with 24VDC will power both devices (using a buck converter for 5VDC). Its placement will allow for very low coax loss, due to the lack of distance between the antenna and SDR (software defined radio) connected to the Pi.