Bluetooth Classic

Classic phone brought to the future.

Author
Published
June 29, 2010
Reading Time
3 minutes

 

Classic Bluetooth Headset Power

Although it was produced for 30+ years and in quantities of millions, this handset is now a relic.  My eight year old nephew has never seen it before.  Technology has progressed and phones are now designed to facilitate ever increasing levels of functionality.  As is often the case, with all that is gained, something is lost.

iPhone Bluetooth Classic Headset

Everyone who gives the phone a try immediately cracks a smile.  The nostalgia is fun but there are also functional benefits.   First, the proximity of the microphone to your mouth and the large speaker make it drastically better at capturing and outputting audio.  Secondly, the face enveloping form creates a more focused and intimate conversation. Somehow this small change in device shape causes the user to stop multitasking and focus on the conversation.

This electronics mash up combines the retro handset with a standard Bluetooth headset, a headphone amp, a few RadioShack components, and some bespoke parts.

The existing microphone and speaker were scrapped in favor of the Bluetooth headset’s microphone and RadioShack speaker.  The Bluetooth headset is mounted to a custom rapid prototyped carrier in the microphone side of the headset.  The speaker and amp are mounted to another custom carrier located on the other side of the phone.  The headphone amp was used because the Bluetooth headset couldn’t provide enough power for the larger RadioShack speaker.  A pair of digital switches allow the single external button to manage the amp power and headset power.

The bespoke power/answer button needed to have the right look to really emphasize the irony.  The button was created from an acrylic tube, aluminum rod, snap dome switch, and white LED.   The LED color was tinted yellow with Kapton tape to give the illusion of a filament based lamp.

The end result is playful, surprisingly functional, and draws many second looks from passersby.

The next revision will employ an accelerometer to allow the user to answer a call by simply picking up the phone, further emulating the original experience.

IMG_0693_E

Components:

  • Vintage ITT phone handset – Removed from late 1970’s Princess phone. No, I’m not joking.
  • Samsung WEP 460 Bluetooth headset – The cheapest one sold at RadioShack.
  • FiiO headphone amplifier – Available through eBay and shipped straight from Hong Kong.  The battery from this devices is used to power the phone.
  • STG719 SPDT Switch – There are lot of options out there but I had these lying around.
  • Cree XP-E LED – Serious overkill but, again, I had it lying around.
  • RadioShack 8 Ohm speaker
  • 3/8” OD, ¼” ID Acrylic Tubing
  • ¼” OD Aluminum Rod

Bluetooth Headset Digital Switches

Technical Notes:

Although the Bluetooth headset and headphone amp share a battery, the switching circuit is required because of the differences in how the power button is wired in the two devices.  In one of the devices the button closes a circuit to ground while the other closes a circuit to the positive battery lead.  Ideally a speaker that makes the most of the headsets modest output would be used and the amp would be omitted.  This would make the entire device much less complex.

Coulter