A couple of months ago I decided to tackle my first tube radio restoration and decided to choose a large console with a
built in phonograph so I could enjoy my 30's and 40's records on a 'modern' turntable.
The model I rescued was a Philco 41-608 (model 75 in Canada) which was made in 1941 and had what I thought to be a gorgeous
bakelite (although a little over-sized) pick-up head (pictured below)
Little did I know this pick-up would cause me so much grief but also so much motivation to get it functioning properly...

It was called "The Beam of Light" and uses that beam of light to generate the audio signal. I've seen some refer to it as the
earliest form of CD but I don't think there are any similarities (I don't know much about CD technology).
Here's how it works...
The Radio sends power to a light bulb located inside that giant pick-up head and is
sealed in a tube with a magnified glass focusing the light into a beam which is pointed at a tiny mirror at the front of the
head. That mirror is mounted to a small shaft which is connected to a sapphire stylus which as it tracks the record, vibrates
the mirror, which transfers the vibrating beam of light to one of the earlier forms of photovoltaic cells (a tiny solar panel).
The signal generated from the photocell is amplified and viola! you have music!
Here's a pic of what the inside of the head looks like and a link to a website dedicated to Philco (where I found the image).
http://www.philcorepairbench.com/phono.htm

A video of it working (not mine)
[youtube]http://www.youtube.com/watch?v=Xi9Bjxx7cdU[/youtube]
and of course, just to toot my own horn a little bit, the before and after pics.

