The model railroad industry has gone in almost complete denial that thousands of us still run with DC throttles. An exception is MRC with its various transistor power packs. They also make a walk around a unit called the CM20 of which I have for my mainline cab and could now use a second one. This is ideal for staying with your train where ever it is around the layout. This system allows you to unplug the handheld unit and move it to another telephone jack where ever you installed them around the layout. The train continues at the same speed while unplugged. For my yard, I don’t need that elaborate of a system that costs about $200.00 for a local control throttle. To save time, I would have purchased a simple handheld transistor unit, but no one makes them anymore. The commercial ones I used in the past have all burned out so they’re in the dumpster. The picture of the home built one you see below was built 33 years ago and it still works fine. It consists of three components. An 18-volt power supply, a filtered DC circuit on a perf board, and the simple transistor throttle itself. If you know nothing about electronics, find the book below and you will be able to master what I call “Caveman” electronics. I purchased the second printing of this book in 1975 and the author did well by assuming the reader knows nothing about electricity. I have built many projects from the book and got them to work even thou I had to substitute some components. Now that my second throttle works, plans are underway to build a high powered walk around the mainline controller.