04-11-2021, 10:52 PM
Hi,
When I restored a 41-608 I had to create a photocell pickup, create my own stylus/ The original photocell was dead, however the original bulb was still good. I didn't attempt to take it from the socket for fear I'd break it' It was stuck tight.
I didn't go the photo-diode method, but went with a photocell. A friend sent two of the small rectangular cells which I connected in series. In bright light they put out about 2.7V IIRC, it's been a while.
Mounted then new cells in front of the original cell. The bulb didn't seem as bright as the photos I"ve seen online with the bright head shell, I was able to adjust the voltage to max. The Voltage came from the OSC circuit I believe and was separate from any filament supply. The 'brightness' control for the bulb was a trimmer capacitor. The current that came from this section is said to be pure DC and had no ripple.
Upon testing I had the head shell off, and was getting sound when the stylus arm moved. But, there was a hum! All groiunds were in place, but oon found out that the cells were picking up the incandescent light from the light fixture in the room. The cell was picking up the 60cycle pulese from the lamp bulb overhead
I then used an LED flashlight, it also 'heard' the pulsations on hi beam and especially the low beam where the LED pulse rate was lower.
The stylus are impossible ti find so I have to find pics, then create my own. I used some springy thin copper sheet. about the same thickness as original. I made a tiny hole in the copper strip so that a generic ruby stylus made for 78 rpm would stick through. IIRC the original had solder on it? Or it was squared off I can't remember, but the stylus assembly was now on the head. Proper angle of the stylus was done close as possible.
Record test was very good. I was getting some kind of metal "ringing" sound occasionally. The changer sections worked flawlessly, I had ordered the two idler wheels from VM.
The customer was happy, I was also and really I don't like to fool with phonos. I had never done a BOL so I convinced the owner to retain the unique turntable. I don't think I'd fool with another one.
When I restored a 41-608 I had to create a photocell pickup, create my own stylus/ The original photocell was dead, however the original bulb was still good. I didn't attempt to take it from the socket for fear I'd break it' It was stuck tight.
I didn't go the photo-diode method, but went with a photocell. A friend sent two of the small rectangular cells which I connected in series. In bright light they put out about 2.7V IIRC, it's been a while.
Mounted then new cells in front of the original cell. The bulb didn't seem as bright as the photos I"ve seen online with the bright head shell, I was able to adjust the voltage to max. The Voltage came from the OSC circuit I believe and was separate from any filament supply. The 'brightness' control for the bulb was a trimmer capacitor. The current that came from this section is said to be pure DC and had no ripple.
Upon testing I had the head shell off, and was getting sound when the stylus arm moved. But, there was a hum! All groiunds were in place, but oon found out that the cells were picking up the incandescent light from the light fixture in the room. The cell was picking up the 60cycle pulese from the lamp bulb overhead
I then used an LED flashlight, it also 'heard' the pulsations on hi beam and especially the low beam where the LED pulse rate was lower.The stylus are impossible ti find so I have to find pics, then create my own. I used some springy thin copper sheet. about the same thickness as original. I made a tiny hole in the copper strip so that a generic ruby stylus made for 78 rpm would stick through. IIRC the original had solder on it? Or it was squared off I can't remember, but the stylus assembly was now on the head. Proper angle of the stylus was done close as possible.
Record test was very good. I was getting some kind of metal "ringing" sound occasionally. The changer sections worked flawlessly, I had ordered the two idler wheels from VM.
The customer was happy, I was also and really I don't like to fool with phonos. I had never done a BOL so I convinced the owner to retain the unique turntable. I don't think I'd fool with another one.
