Lionel 1011 transformer repair

The Lionel 1011 transformer was a small starter set transformer from the post-war era. It only had a 25 watt capacity, but small transformers like this can still be useful on the bench or for powering accessories. Here’s how I fixed one.

My wife found a box of Lionel track at a thrift store for a low price and brought it home. As I was sorting through the track to separate out the usable sections from damaged sections that needed to just be salvaged for the ties and the pins, I found a 1011 transformer in the bottom of the box. And I could tell right away it wasn’t safe to use, because the power cord was crumbling.

Since not very many people talk about these transformers, I thought it might be fun to fix. Unless they are just completely worn out, there isn’t much on these that can go wrong other than the power cord decaying with age. Whatever Lionel used to insulate its power cords in the 1950s and 1960s was definitely suboptimal.

The 1011 came with inexpensive Lionel Scout sets, so they are low end transformers at best. But there are any number of reasons you may want to fix one.

Opening a Lionel 1011 transformer

I’ve seen people cut into the case with a rotary tool, but that is completely unnecessary. The Lionel 1011 was definitely not designed to be opened and repaired, but you can do it. Simply find the biggest flat-bladed screwdriver you can, then insert it between the metal base and the bakelite top, and twist and pry until it loosens. I pried on one side, then switched to the other side, and just repeated until the base came free.

With the base loose, the transformer core may just drop right out. Or the process of prying off the base may wedge it in there a bit, but a bit of jostling will free it.

The wiper wipes across the top of the transformer coils to generate the variable voltages. The common post just wires directly to a terminal on the transformer core. Double check the common wire to make sure it is securely connected on both sides. Also check to make sure the wiper hasn’t worn completely through. But the main problem on these is the power cable. The power cable attaches to a pair of solder joints at the top of the transformer.

Replacing the power cable

You can get replacement power cables on eBay, but they usually cost more than one of these transformers is probably worth. Home Depot sells an extension cord for $2.58 that uses a heavier wire than Lionel used. The store nearest you probably sells an identical cord for a similar price.

I cut the receptacle end off, stripped back about a half inch of insulation from the end, twisted the wire, tinned the ends, and then regretted it. Because the wire is a little bit heavier gauge than the original, after I tinned the wires, they didn’t fit. While tinning is almost always a good idea, we found the exception here.

Desoldering the original cable wasn’t too bad. Even with my wimpy 25 watt soldering iron, I was able to quickly desolder the cable leads using cheap desoldering braid. I also cleaned off as much of the excess solder from the terminal position as I could.

Slide some heat shrink tube onto the end, then bend the wire into an l shape and sneak the new wire into the holes in the terminal.

After soldering the wires into place, slide the heat shrink tubing up over any exposed copper and shrink it into place to eliminate the possibility of any short circuits. Now the transformer is better than new.

Tie a knot in the cord as close to the transformer core as you can get it. This knot serves as a strain relief to protect the cord from being yanked out and damaging the solder connections.

Reassembling a repaired Lionel 1011 transformer

Place the core back into the transformer case. The side that goes toward the top is the one that has wear marks from the wiper.

I also like to paint the base. The cheapest black rattle can paint from your nearest store is fine for this.

Check your work by giving the transformer my basic safety test to make sure there are no short circuits.

Once the base is dry, place the thick fish paper insulator back into place, then press the base onto the bottom of the transformer. Hand pressure should be enough to squeeze it all back together.

And that’s all there is to it. Some will argue that a 25 watt Lionel transformer isn’t worth bothering with, but chances are you can find some use for it. And fixing it keeps it out of a landfill and provides you with a bit of practice that will serve you well when the time comes to fix something more valuable. The 1011 is no KW or ZW, but there’s value in fixing old things beyond just the monetary value of that specific item. The experience is valuable too.