Wednesday, February 23, 2011

Restoring then hacking an Emerson model 888 Pioneer transistor radio

Recently I purchased this old Emerson model 888 Pioneer transistor radio built in 1957. It has 8 transistors, 4 for the RF and 4 for the audio circuitry. It uses a transformer coupled audio phase splitter and audio output for a total of 2 audio transformers. It does not use negative feedback in its amplifier. For these reasons (and the fact that it uses early transistors) this radio will have a unique sound compared to modern audio devices.

My plan is to restore it to original working order by re-capping all electrolytics and paper caps, then hack it so that i can play my ipod through it but also still be able to use the radio.

I will do this by using the ear phone output jack on the side as an input, where the radio AF out to the audio amplifier circuitry will be interrupted when an audio source is plugged in. No case modifications will be necessary.

Stay tuned...