[Eric T]

Every time I show off another radio on FB, my mother-in-law asks me when I'll fix her Beam Of Light record changer.
It's getting irritating and she keeps claiming she'll just get someone else to fix it (as if she can take it to the non-existent record player repair shop down the street and they'll even know what it is). 

So here's what I need:
1. Something to replace the bad photocell.
2. New rubber for the drive bell.

The repair doesn't look hard, but the materials appear to made of weapons-grade unobtanium. I don't even know where to start looking.
 

[sam]

eric
shes gona be on you awhile
their are 4 of us trying to fix these darn sons of bit hes 
hear you could use Rowe bill acceptor BA5 or BA55
sam

[Eric T]

While poking around the interwebz, I came across this article: http://speakyssb.blogspot.pt/2011/12/pow...-leds.html where a guy uses a standard LED to produce voltage like a solar cell. 

I tried it myself, and I get 1.4 volts max out of a white LED with a light up close. 

Next, I connected it to my o-scope and quickly waved a flashlight across it. I got decent deflection with the light. I'm going to need to do some more experimentation, but this seems like it might be a promising way to replace the photocell. 

Edit: Or maybe just try out some photodiodes or phototransisters. Derp.

I still need to do something about the rubber for the drive bell.

[Eric T]

Some more information I found:

http://drzeesradiorepairblog.biz/media/b...1411097430

He suggests using a silicon photodiode to replace the original photocell. I'll get some ordered and see what I can do with it.

[Marsupial]

it would make sense to be able to replace antiquated hardware with modern replacement... a photodiode seem to make sense. I find the whole idea intriguing. I hope good will come out of this and to have a beam of light replacement guide posted somewhere. Perhaps even a "make your own beam of light"?

[Eric T]

it would make sense to be able to replace antiquated hardware with modern replacement... a photodiode seem to make sense. I find the whole idea intriguing. I hope good will come out of this and to have a beam of light replacement guide posted somewhere. Perhaps even a "make your own beam of light"?

I hope to get this thing working and be able to share information about it here.

Here's a little update:
I checked the original photocell a couple years ago and it tested good.
Last time I tested it, last Winter I think, it was bad.
I just tested it again and it works.  Whiskey Tango Hotel, over.

Maybe it's susceptible to humidity or some other environmental factor.

I think I'll just proceed as if it's bad, and go with a photodiode of some type. They are supposed to have better high frequency response than the original, anyway.

[Marsupial]

maybe there's an intermittent connection of its prongs?
How have you tested it?

[Arran]

 The old photocells were likely selenium based anyhow, so just like the selenium rectifiers they will likely have a shelf life, and would have a higher forward dropping resistance then a silicon based photocell so likely less sensitive as well. I had read about using a photocell from a vending machine coil acceptor in place of the selenium units, which is probably the best solution in the long given the cost.
Regards
Arran

[Mr Grumpy]

I used one of these for my BOL and it worked like a charm.

http://www.ebay.ca/itm/UDT-silicon-photo...19d881eb56

[Video: http://https://www.youtube.com/watch?v=_NGECVSrew0]

[sam]

hi mr grumpy
can you show pic on how you mounted
thanks sam

[standardtwin]

I have a 41-608, that had the tonearm redone by Chuck several years ago. I'd like to see how you refurb it too, sounds fairly easy.
I don't mean to highjack the thread, but since this is being discussed, may I ask what spring is used in the tonearm for pressure?. Mine has none, and I can't see where it would go.
How does one get the turntable off the spindle, mine has a H**l of a rumbling noise to it, and I can't seem to get it off.
Despite this, is does play records.....

Thank you
Mike

[Mr Grumpy]

I probably won't be able to get a picture til the weekend if you need one.  I've used my superb Paint skills to describe what I did.  I removed all of the hardware that the Photocell was attached to, If I remember correctly it was two screws that attached the Photocell holder to the head. I made a very simple 'L' bracket out of sheet metal and drilled two holes into it to mount it to the head (using the same two screws).  The L bracket holes were actually oval so I could adjust it back and fourth.  Then I just double sided taped the sensor to the bracket.  Pretty crude but it worked really well, especially after I replaced the rubber bushings holding the mirror and needle.

   

[Mr Grumpy]

I have a 41-608, that had the tonearm redone by Chuck several years ago. I'd like to see how you refurb it too, sounds fairly easy.
I don't mean to highjack the thread, but since this is being discussed, may I ask what spring is used in the tonearm for pressure?. Mine has none, and I can't see where it would go.
How does one get the turntable off the spindle, mine has a H**l of a rumbling noise to it, and I can't seem to get it off.
Despite this, is does play records.....

Thank you
Mike

I don't think it uses a spring. Mine only has an adjustable counter weight at the back of the tone arm.
I also think my turntable just pulled off (without any type of fastener holding it in place) It may be corroded and
needs a little persuasion?

[Arran]

 I wonder if these will work, it seems much less expensive:

http://www.ebay.com/itm/10-PCS-PHOTODIOD...257d90d021

Regards
Arran

[Eric T]

Sorry folks, this project got temporarily on hold.

My wife got very ill and went into the hospital for 4 days, 2 in ICU. She's out now and just about fully recovered. This was followed by somebody hacking my debit card and a couple other things going wrong. It's been a rough couple of weeks, but I think we're coming out of it and the sun is shining in our life again.