I've had this pair of Motorola walkie talkies for about a year now. They were cheap and cheerful and perfect for contacting my mates while we were snowboarding.
However I discovered that taking my gloves off and unzipping my jacket pocket to answer my mates calls every 5 minutes can get quite frustrating, and cold. Especially when it turns out not to be my mate but some random talking to his mates on the same channel.
Anyway, long story short, I decided to install a headphone socket so I can hear and respond to my mates without having to remove the radio from my pocket.
Step 1: Crack It Open. (Not Literally).
So here you have the main ingredients for this mod. 1 Motorola walkie talkie and a 3.5mm headphone socket salvaged from an old PCI 56k modem. The socket has two switched contacts so that when a headphone is plugged in it breaks the circuit to the radio's speaker and therefor only plays sound through the headphones. I find this feature particularly useful when I'm playing airsoft/paintball so the loudspeaker doesnt give away my position to the 'enemy'.
If you havent got an old PCI modem to destroy you can buy the sockets from Maplin(79p). I'm sure you guys across the pond can pick them up from RadioShack, and DickSmiths if you're Down Under.
Anyway on with the show. Find the screws, mine were under the battery cover and unscrew them. Put them somewhere safe, I know what you're like!
Gently pull the casing away from the electronics being careful not to rip the wires from the loudspeaker.
Step 2: Prepare the Headphone Socket.
The headphone jack has 5 pins. 2 for the radio, 2 for the loud speaker and a larger one at the front for mounting to the pcb. Cut the big one off, or at least fold it back so it no longer sticks out.
I can't say how you'll need to wire up your socket but the pins on mine were paired side by side. Solder a black wire on one and a red on the other for each pair.
Step 3: Connect the Headphone Socket.
Dettach the loudspeaker from the radio's PCB but keep the wires on the speaker, it'll save a fiddley soldering job later on.
You'll need to do some testing (with batteries installed) to ensure the correct circuit is cut off when a headphone is plugged in before soldering in the socket. Otherwise you'll just end up connecting a speaker to headphones and that just won't do!
Once you know which wires go where, solder it all up good 'n' proper. I left the old leads on the loudspeaker as it was easier to just twist them together, solder and heat shrink tube or electrical tape them.
Note: Sorry about the blurred images. They all seem sharp when you're viewing them on a 2" lcd.
Step 4: Preparing the Case.
Now you need to make a hole for the socket to go. On this little walkie talkie it was a right 'mare. There's very little space but on larger radios you could probably stick it anywhere. I would've like to have had the socket on the top but limited room meant it had to point out the back. Oh well.
I measured the height and width of the headphone socket and using a sharp scalpel, marked where I needed to cut a hole.
Clamp the case down and drill, Dremel, cut, saw, melt that hole right out. I chose the Dremel with a router tip. Messy job but soon tidied up with a scalpel. Please note that the electronics are still out of the radio case at this point, Dremel plus PCB equals whole lot of your time wasted.
You are now good to close the radio back up but first I'd stick the batteries in again and make sure it's all kosher. Nothing worse than screwing it all back up only to find out that you're useless and you have to undo it all again.
Step 5: Close Up the Case and Go Snowboarding!
Screw it and glue it. Well at least screw it. I decided to use a little hot glue to secure the headphone socket in place but if you cut the hole accurately you might not need to do the same.
And that, my friends, is it! Now do it all again for your other walkie talkie otherwise your mate will moan. I managed to do the second one in about 20 - 30 minutes.
I hope you enjoyed my first instructable (there I said it, it's my first!). Feel free to comment all you like.