Telephone Handset to Cell Phone

There's more to it than that; I seriously doubt a cellphone can drive a high-impedance telephone earpiece or work with a carbon granule microphone as you would find in a "real" handset of this vintage.

On 9 Jul 2005 18:30:09 -0700, snipped-for-privacy@larwe.com wroth:

I thought about those same details and came to the conclusion that the cellphone audio output probably would drive a old phone's earpiece OK. Most cellphones have volume controls that can make the audio much louder than is comfortable for me.

Also, most cellphone microphones are those amplified electret (capacitive) types and need a bias voltage to drive the amp in the mike. As far as the cellphone knows, there appears to be a virtual variable resistor of around 1k to 10K between the mike input and ground. The virtual resistor's value appears to vary at an audio rate and that produces a variable voltage at the mike input. An old carbon mike element is just a real variable resistor where the resistance variations are at an audio rate.

I'll bet the whole result would be a usable hack.

Jim

You only need the handset, not the mechanism, of the phone, so you shouldn't be burdened with the RJ-11. Cut off the connector at the end of the handset (curly) cable and check out the wire colours. You can unscrew the mouthpiece and earpiece of the handset to check out which colours go where - you now know half your task!

The connector you need to plug into the cell phone would, I'd have assumed, varied from manufacturer to manufacturer. I haven't actually seen one with a

Be real retro and put the cell-phone into a shoe - now *that* would get looks, Max!

Ken

If in doubt, replace the earpiece and microphone with something suitable. No biggy, and it's only the look that is 'retro' (it's the concept that's questionable).

Cheers.

Ken