# 4B Transformer pics



## chrisallen21 (Sep 1, 2016)

Started to look at cleaning up one of the 4B transformers I have. I definitely have to replace the electrical cord on it and so I cracked it open to take a look. I have included the pics below but have a question. Everything looks pretty clean but I was wondering if the wear from the speed control is anything I can really do something about. I know it is just normal wear from usage and that the real test will be when I actually replace the cord and plug it in and test on a meter but thought I would throw it out to the group for opinions.


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## T-Man (May 16, 2008)

It looks ok, it should be fine.
:thumbsup:


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## AmFlyer (Mar 16, 2012)

Looks like you have one of the later production 4B's in the Bakelite case. They are less common than the gray metal case 4B transformers.


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## flyernut (Oct 31, 2010)

Looks ok. I would scuff up and try to remove the wear pattern. I've done this on several ZW's I have.


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## chrisallen21 (Sep 1, 2016)

What is it that you use to scuff up the wear pattern?


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## flyernut (Oct 31, 2010)

Maybe I'm wrong, but I would use some 2000 grit wet/dry sand-paper, or some emery cloth.


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## highvoltage (Apr 6, 2014)

Looks like the roller has worn off and the metal is starting to dig into the coil. Definitely replace the roller before you put it back together.


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## chrisallen21 (Sep 1, 2016)

What is the 'roller' you refer to? The contact spring arm that swings back and forth on the coil still has a 'bump' on the end of it (as shown in the picture) which matches the groove on the coil. Is there supposed to be something else? I couldn't find a parts diagram for a 4B specifically but the 11/2 seems to be close: http://myflyertrains.org/gallery/album211/22004_22020


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## AmFlyer (Mar 16, 2012)

The 4B has a wiper arm attached to the exterior knob. It does not use a roller. In the Gilbert factory service manual the 22020 diagram works for Bakelite cased 4B's.


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## chrisallen21 (Sep 1, 2016)

I forgot to include a shot of the existing electrical cord. I am sure you will agree that it was in need of replacement. I think my grandfather should have been a little more worried about a possible electrical fire with his boys when they were playing with the trains!


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## The New Guy (Mar 11, 2012)

chrisallen21 said:


> ...I think my grandfather should have been a little more worried about a possible electrical fire with his boys...


What, he taped it up. 

Did you source a non polarized cord yet? I'm partial to these guys, but I'm old.


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## Aflyer (Nov 10, 2010)

I would just clean the wear pattern in the coil, from the wiper with denatured alcohol and a soft cloth.
Make sure the alcohol doesn't soften the shellac/varnish on the coil windings.
You could probably also use electrical contact cleaner if you prefer or have some.


Aflyer


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## chrisallen21 (Sep 1, 2016)

I have one last cord pic to post. Out of the 5 transformers that I replaced the cords on, this was by far the worst. 

I didn't even try to plug this 4B transformer in before replacing the cord but after the replacement, it buzzes quite loudly unlike the other two 4Bs and 1 1/2s I replaced the cords on. I saw this link (http://themotordoctor.com/transformers.htm) which indicates the following:

<snip>
If your transformer gives off a loud BUZZING noise, this is the result of 60Hz vibration caused by the transformer's core laminations moving. This should be serviced as this vibration can cause damage to insulation in contact with the moving metal.
</snip>

Is this something that can be fixed by a relative newbie like me or it is time to use this one for parts? If it helps, the date stamp on the back plate is 1954 and it is the backalite casing.

Here is the cord picture:


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## AmFlyer (Mar 16, 2012)

That cord is not usable. There is not much a user can do with a 4B. Looking at the service manual as long as the metal base, 11 is snug to the Core, 10 using the screws, !2 that is all there is to adjust. If it has an objectionable hum I would just buy another, they are not expensive.
I quit using the original Gilbert transformers years ago, when I bought my first TMCC engine. The new transformers have fast acting protection on the low voltage output to protect the electronics in the engines. I also was uncomfortable with 65 year old 120V transformers in use in the house.


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