1033 rectifier disc

[Ted_Yor]

I have a 1033 transformer. The whistle is not working. When I turn the whistle lever the train will go slightly faster, but the whistle or horn does not engage. I figure I would replace the rectifier disc and this does not appear to be a huge chore.

I haven't removed the disc yet. When I examine the disc it appears pitted and brown in color. Around the edges where the disc makes physical contact with the plate it is mounted on,  is what appears to be a dry white powder. Does any one know if this is a thermal grease or is the white substance corrosion caused by dissimilar metals?

 

Ted

[TrainLarry]

What you observe is probably some corrosion. There was no thermal grease used on the discs, or anything else in our hobby in those days that I'm aware of. Replace the disc with part #1041-13 available from online dealers.

Larry

[Ted_Yor]

Thanks Larry;

 

I have the disc. I just stare at these things for a while looking for anything that will cause me problems.

 

Many thanks

Ted

[Roadmaster]

Hi Ted.  A couple of tips:  

Don't touch the surface of the disc.

 Be careful when removing the disc; the bakelite insulators in the center will be brittle, handle them gently; be gentle with the handles when removing them, their also old & brittle.  

If the reverse/whistle assembly is loose or not contacting well, now is the time to tighten the switch shaft assembly & clean the contacts.  

I replaced the copper oxide disk with a post type diode in all of my transformers.  It really improves the whistle reliability

Byron

[lionelsoni]

It's not a big deal; but an ordinary silicon diode has a higher forward voltage than the original copper-oxide and therefore is a slightly less efficient rectifier.  A Schottky diode is a closer match.

[Ted_Yor]

Finally had time to install the disk. Cleaned off the white powder I talked about above. I was careful in handling the new disc. At first it worked only intermittently, but I tighten the disk to the plate a little more and cleaned the contact on the switch and it appears to work without a hitch.

 

I think next time I have to do this I will switch to the Schottky mentioned above.

 

Thanks to all the suggestions. 

 

Ted