DIY

TELEPHONY

RETRO WIRELESS HANDSET

Adding Bluetooth to an old phone.

By Jeff Keyzer

Like it or not, Bluetooth headsets have become a part of our lives. Formerly worn only by stuffy corporate execs and the social elite, these devices have become ubiquitous, thanks to dropping prices and hands-free driving laws. A quick search online shows that a new Bluetooth headset can be purchased for less than $20. This is great news for makers because now we can use them in all sorts of projects!

Photography by Jeff Keyzer

My wife gave me her old Motorola HS820 Bluetooth headset when she upgraded to a newer model. Of course, I immediately tore it open. Inside, I found a small printed circuit board, a lithium polymer (LiPo) battery, an electret microphone, and a tiny speaker.

I came across a vintage ITT telephone handset on a recent trip to Weird Stuff Warehouse in Sunnyvale, Calif. The instant I saw it, I knew exactly what to do:

MATERIALS AND TOOLS

Bluetooth headset An older, larger model is better since it will likely be easier to hack.

Vintage telephone handset The kind with round, removable ear and mouthpieces.

Superbright 5mm blue LED All Electronics part #LED- 122, allelectronics.com

Panel-mount LED holder All Electronics #HLED- 3

Normally open panel-mount push-button switch All Electronics #MPB- 1

Coaxial panel-mount DC power jack; matching plug Fine-gauge insulated stranded wire

1kΩ resistor You might need some other value, so have an assortment on hand.

Soldering iron

Hot glue gun

Multimeter with continuity tester

Wire cutter/stripper

Handheld drill and drill bits

Small screwdriver

151 Make: