The Talking Machine Forum — For All Antique Phonographs & Recordings

...Not a comedy sketch, but I thought I'd share something a little different that some may have never known existed.

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.

A handsome set, and a fascinating reproducer system. Never knew they existed. Sounds like the system might be along the same principles used by film motion picture projectors.

Clay

My maternal grandfather had one of those 1941 "beam of light" Philcos. It was gone by the time I knew him (1960s), but I've seen it in photographs of his living room from earlier days. Though I'm an antique phonograph guy, I have done research into the radios and radio/phonographs owned by both sets of my grandparents in the 1920s, 1930s, 1940s. My maternal grandparents bought a Michigan-made Sparton "Equasonne" radio in 1928/29 and kept it all the way through the 1930s--as they (like so many other families) could not afford to buy much beyond basics through the Depression years. But by 1941 the economy was picking up again and I bet TONS of households bought the Philcos.

My other set of grandparents (paternal) bought a Majestic radio around 1930 and kept it into the late 1950s! That household had no phonograph, even back in the 1920s as far as I can tell. My paternal grandmother resisted getting a television in the 1950s, saying that it was only so much foolishness (she no doubt agreed with Newton Minow about TV being a "vast wasteland" -- ). But one of my uncles finally made her accept the gift of one after he said "Well, your grandchildren are going to want to watch something when they're over here."

The technology of all this stuff is interesting, but the social history of it even more so.

Ralph

I had heard of the Beam Of Light Philco but have never seen one before today - many thanks for changing that! Whilst the data is still analogue ie. not digital binary code and 'bits', there are clearly similarities to CD reproduction, with the laser being in place of the light beam. This was an amazing device and clearly shows the thinking of the day - how to improve the accuracy of electronic pickups.

How does it compare to conventional pickups?

Wondering if the bulb is replaceable, or if once it burns out that is the end of the story?

Clay

Did you restore the BOL pickup yourself or have it done? I have read quite a bit about these on antique radio forums, but have never owned one nor have I even had the opportunity to hear a restored one in person. The technology used here is very similar to that used in optical sound film projection or the "light ray" microphone used by Brunswick early in their electrical recording years. It bears no resemblance at all to CD or DVD technology. There is, however, a process which uses a laser to directly read conventional phonograph records and which I understand works quite well, but it came along too late to be widely marketed. This process is similar to CD or DVD players in operation.

Jim

@Steve - It has much better low frequency response, much better and stronger bass than the conventional reproduction of the same
era. It's very sensitive to adjustments though, and can have a very garbled sound if not set up correctly.

@Clay - The bulb is replaceable but exact replacements are almost impossible to find. I believe the filament is a special type but
I've had to replace the photocell with a modern one so I doubt that a modern 3 watt bulb wouldn't work.

@Jim - I rebuilt the pick up myself, the mirror and bushings were scratch built and the photocell replaced with a tiny photovoltaic
cell I purchased on ebay. Luckily the sapphire and light bulb didn't need replacing.

I thought it was really neat technology for the era and considering they were only produced in 41 and 42 I figured it was
definitely worth saving. I had many 'experts' advise me that the best thing to do would be to remove and replace it with a more
modern turntable.

Congrats on getting your Philco BOL phono in such nice shape. Next, you need to get one of the top-of-the-line Philco models. Starting in 1939, Philco was the first radio/phono maker to offer WIRELESS - YES ! remote control. Check out this video of the model 41-616 which was the top dog Philco of 1941:

http://www.youtube.com/watch?v=5SDWNGrm9Gk

It has the wireless remote, the BOL changer, and it's all nicely demonstrated. This particular model used the VERY rare Webster-Chicago "triple slicer" record changer that was not used in any other Philco model. Not many were sold, and almost none still survive because the changer used gobs of potmetal which has since turned to warped shards and dust. The one in this video is the only one I know that exists in working condition.

I have the similar 1942 set, model 42-1016 which is in the same cabinet and also has all the bells and whistles. It uses the later Webster BOL changer with 2-speed operation at 78 and 39 rpm. Not a misprint. Philco was the only maker to offer the 39rpm speed. It is exactly half of 78rpm, and the changer also had a variable speed vernier control. To allow the setting of the proper 78rpm speed, the changer had a stroboscope pattern printed on the periphery of the platter with neon lamp illumination built in. So you could also set the 39rpm speed exactly with the same strobe pattern. The 39rpm speed was provided to be used with the Philco home recording option.

gregbogantz wrote:So you could also set the 39rpm speed exactly with the same strobe pattern. The 39rpm speed was provided to be used with the Philco home recording option.

A-ha! That explains something I'd wondered about. I found some Philco home recordings sometime back with a bunch of FDR speeches on them that played back at about that speed and I had no idea what would have recorded them like that! I ended up playing them at 45 and slowing them down about Mystery solved, thanks!

By the way, the quality of the recordings, obviously off-ar, is pretty good.

Sean

Thanks for the link Greg, I've read about the Mystery Control but I've never seen one working before.

I have to keep my number of console radios to a minimum as I'd have to move out a gramophone to make room,
but I have been eye-ing a Crosley grandfather clock lately