Hi Neck's and Neckette's,

I am wondering if there is anything cheap I can get on eBay to plug into a PC or laptop to be able to switch a link box on and off??
I have tried looking around and found a few things but they seem to just be USB powered and not controlled by the PC.
Have got computer into link box already and be very handy to have way of using the computer to switch link on and off.
Have seen WiFi plug sockets etc but would rather try something like this. Probably will need some kind of software too for switching relay on or off.

Cheers all in advance.

I think what you need is called a USB relay, you could then connect it to the manual operation button of a WiFi socket

Not cheap but not expensive. Seems to be controlled via software if that’s what you wanted.

https://cpc.farnell.com/cebek/usb-t-101 ... dp/HK01587

The common way of doing this in the commercial world is to use "sub-audio" tone control. If you use a control tone of (say) 8 - 10 Hz, it's easy to filter out from the audio going to the main rig, so it doesn't get radiated. You can then detect its presence with a simple tone decoder IC like the NE567. The '567 has enough output current capability to drive a small relay directly.

We also used tone bursts (and some simple CMOS logic) to turn rigs on and off remotely. One approach used the HT12E encoder and the HT12D decoder ICs to prevent unauthorised use of our gear!