I need a watchyamacallit for a special application

I have a special application where I’d like to hook up a cheap 2 way radio (like Motorola FRS) into the line level output of an audio source. Specifically a computer. I was hoping to be able to utilize the VOX function of the radio so that when there is sound, it automatically transmits. Does anyone know of an inexpensive off the shelf item that can accomplish this? If not, how about the plans to make one?

By the way, I did try hard wiring the 2.5mm jack to a stereo 3.5mm jack to a MP3 player. Didn’t work… I got the pin outs by ohming an external mic/speaker for one of the walkie-talkies. The radio I using to test was the Motorola t9500 FRS radios.

For those curious, I’m a CCTV integrator. For a job coming up we’ll be using external sensors that integrate into a CCTV system. When ever one of the sensors are triggered, it pops up user defined alerts and sounds on a remote computer. Instead of having the security guards babysitting the video wall, we’d like to have them free to roam around the 14 acre property to complete their tours. We could accomplish this by having the automatic radio alerts.

I think you are asking too much for FRS radios. There is equipment available that will do this, however it is in the commercial equipment category and is not cheap. You can have a device trigger an event and transmit a code to a portable radio. The radio guard looks at the code and knows what the event is and the location if programmed that way. I have sold systems like this to refineries with a guard at night. Before this system every time there was an event (high pressure, low pressure, door open, door closed, etc.) he had to run back to the command post to see what the problem was and where it was. With the wireless alert system he could be walking around the facility, receive the alert, and go right to it.