DIY Dispatcher Headset audio/mic Switch

[factorone33]

Hey guys. Obviously new to the board, but I searched the entire thing exhaustively (and the rest of the internet) looking for anything relatively close to what I need, but no dice. So, here goes.

I do dispatching at the Kansas Speedway for Fire/Rescue, and while it's not a large, frequent operation, it gets hairy because of what equipment we have (or a lack thereof). We use CDM1250s as our "base station" radios, and then various models of handhelds in the field for units out and about. Several of the other personnel in the office with myself are actual dispatchers (current or retired) and have complained quite often about a lack of clarity in audio from the CDM1250s (because let's face it, the internal speaker is less than stellar) without having to crank the volume up to 12.

So I've set out looking for a headset solution. But there aren't any that aren't stupid expensive. Which leads me to this.

The short of it is this: I have an accessory plug for a CDM1250 that I will use to interface this headset -> http://www.amazon.com/gp/product/B00OUK ... UTF8&psc=1 to the back of the radio. But it'd be really, really nice if I could also interface it with our phones. Commercial interfaces are available, but I'm doing this on my own dime and time, and can't drop $1200 on one of those.

Thus, I need your help. I am not an electrical engineer, but I can read and interpret a circuit schematic/diagram to be able to build something. I'm assuming that I'd need to build something that is:

• Impedance matching
• Shielded
• Hot-swappable (if this would even be an issue)

Open to suggestions, and while this isn't 100% necessary, it would be nice to go there with it, and then be able to replicate it for the rest.

Thanks in advance, guys.
BW

[RFguy]

Have you tried an external speaker on the CDM to improve audio quality?

As for telephone/radio headset interface, look at Radiomate.

http://www.radiomate.com/SwitchMate.html

[d119]

http://www.radiomate.com/JackMate.html Seems this would probably cost less if you don't need telephone capability....

[factorone33]

Thanks for the suggestions guys. I saw both of those units, and while they'd be nice to have, I'm doing this with zero budget (the headset I bought was $15, for example).

It was more of a "Can I do this, and if so, how...?" kind of question. It isn't 100% necessary, but is more of a want than a need. But thanks for the feedback guys.