First Time........

[Mathew]

This is goin to be my first time soldering and installing a decoder. I have a cheapie 40 watt solder iron and 3 used Digitrax DH123 decoders. All the locos are older DC loco's. Any tips or advice on soldering or installing the decoder that may keep me from getting into trouble? I have gone to the Digitrax website and looked at how the decoder goes in (as far as what wire goes where) and I think I understand it enough for it to work but again this is my first time for both so........

[Smoke]

A couple tips that will help you out.

-Keep your tip of your iron clean. clean the tip before you solder the next wire so that the joint forms faster.
-Keep the heat on the decoder to a minimum to avoid frying something.
-Secure the wires with tape or something else so that you have both hands free when soldering

[cf7]

I agree with Andrew.

One more tip: ALWAYS make sure the motor is isolated. This is almost a sure fire method to fry one.

[Raeder]

As far as wiring which wire to which spot, here is what I have found works on Athearn Blue Box units.

Red wire to right rail (engineer's side) If you can attach to the metal side of the truck, that's a good spot.
Black wire to the left rail(conductors side of locomotive). Whichever side attaches to the "L" shaped tower, attache the other side to the side of the truck.
Orange wire to the copper strip on top of the motor. Orange is the color of the sunrise, which goes up!
Gray wire to the copper strip on the bottom of the motor. Either bend the tabs back up into the strip, or cut them off. Also put a strip of tape on the frame where the tabs would touch. You don't want a short there!

A clean surface is necessary. A Dremel with a wire wheel will make a shiny spot on the metal where you want to solder real quick. This will clear off the oxidization and be a perfect spot to solder to.

Invest in a chisel tip for your iron. Instead of concentrating heat at one tip, this will spread the heat over a line, and transfer more heat faster. I also use a Radio Shack 40 watt iron, and after I equipped it with a chisel tip, it became a good little worker.

If you are soldering two wires together, strip the ends, put the iron under the wire, and touch the tip on the opposite side of the wire with some solder. When the solder flows, it will try to run up the iron toward the handle, and work into the wire. This will cause your wire to become "tinned." Once both wires are tinned, use a holder to place the wires next to each other, and repeat this trick to solder them together. Make sure your heat-shrink tubing is already threaded on!

Good luck with this. I know soldering is somewhat tough to get started with, but once you get the hang of it, it is a handy skill to know in this hobby!

Kevin

[Mathew]

Thanks everyone. I got in a little practice yesterday, its not difficult but its not easy either. The tricky part for me is keeping my hands steady. I guess where I try hard to keep them steady it makes it worse. Ill keep working on it though. I see now what everyone one was saying with cleaning the tip, it makes a big diffrence in how things turn out.