Monthly Archives: August 2016

Full handset functional

So it turns out that the transformer wasn’t necessary.  I broke out a pocket oscilloscope, and it boosted the voltage from 1.5V pp, to 7.5V pp, and the resulting volume in the earpiece was VERY LOUD, so I tried without the transformer, and it worked perfectly, and at a much more reasonable volume with the […]

It speaks!

Thanks to an impedance matching transformer from Radio Shack, I can now play audio though the handset.  Yay!  It still needs to be a little more polished, but the basic concept works. it_speaks.mov