How-to? Columbia Analyzing Reproducer rebuild...

[De Soto Frank]

I am confronted with my first overhaul of a Columbia Analyzing Reproducer, on a Graphophone BJ "Imperial".

It appears to be an early version of the Analyzing box, with a thumb-screw needle-chuck. The latest patent date, visible through the mica is Jul, 25, 05 [sic].

I have disassembled it easily enough...

I have a few questions:


1) Diaphragm gaskets: I got some tubing for this at Wayne from Ron Sitko, telling him it was for the Analyzing Reproducer, and he gave me a white tubing larger in diameter than is for the Victor Exhibition; this seems to match what I removed from the front side of the mica. What was buried behind it seems to have been a smaller di""ameter white tubing ( Exhibition-size ? ), but it's difficult to tell, as it's really squashed flat. Should this reproducer use the same diameter tubing on both sides of the diaphragm ?

2) "Back-flange insulator / gasket": The reproducer is held to the taper-tube by three machine-screws, through the back-side of the arm. The appears to be a rubber insulator "dough-nut" / insulator inside the arm casting, but it is quite fossilized, and there appear to be some sort of rubber O-rings or insulators around the screw-heads. Was this a one-piece, custom moulded rubber part, or separate rubber washers built-up ? It is fairly intact at that moment, and any exploratory digging would render it useless...

Does anyone make a repro insulator ?


3) Inner rim of reproducer housing: Was the inside rim of the reproducer housing painted black ? Mine is black, but rather crusty... I thought at first it might have been the chemicals in the rubber gasket turning the nickel-plate black... ?


Thanks for your help - I don't want to screw anything up with this...

[Phonofreak]

Frank, Here is what I have done with Columbia Analyzing reproducers. I have used Exhibition white rubber tubing and it seems to work great for me. The larger white tubing doesn't always work, so it is a matter of feel. It's still good to keep both types on hand. First, remove the mica and needle bar. Clean out the gasket residue. The insider face of the reproducer should be nickle, not black. That needs to be cleaned and polished. Hold onto the needle bar and mica for later. I have not found any of the black rubber gaskets that connects from the arm to the reproducer. What I did was get black RTV silicone. You can get that at a good hardware or auto parts store. Put the screws into the back of the reproducer. Apply the RTV into the cavity of the arm. Screw the reproducer to the arm. Remove excess RTV from the arm and reproducer. Be sure to check the inside of the reproducer to make sure none of the RTV leaked inside. Wait about a day or so, and put in the gaskets and needle bar assembly. That's all there is to it. If you have any more questions let me know.
Harvey Kravitz

[De Soto Frank]

Harvey,

Thanks for the suggestions !

I tried the "Fat" tubing, as that is what I had on-hand... it is a tight fit for the outer gasket... I might try it with the Exhibition tubing when I get some. (Perhaps a combination of the two ?)

For the insulator at the back-flange, I was able to ease it out of the tapering arm... it seems to be simply a flat rubber gasket. It was squished enough that there was a little play ( air-leak potential ) with the mounting screws "bottomed".

I had some thin cork/rubber gasket sheet from the garage, so I cut a gasket from that, and inserted it between the reproducer and the original rubber. Seems to work for now.

The needle-bar screws were tightened all the way ( springs completely compressed ) when I started on it... I tightened them about "½-way" on re-assembly. I will see about "tuning" them later...

The reproducer plays nice and loud, w/o blasting or distortion, even on some early electrical records.

Now I just need to get the motor to run at a steady speed...


Frank