Recently bought an older run, probably the first Kato HO SD40 run, I'm trying to install a decoder. Bought a Digitrax DH165K1A, but it doesn't look like it will work. This SD40 doesn't even have a circuit board, just a plastic strip holding a light circuit, and a copper wire running down the side from one truck to the other.. Any suggestions?
Goit a picture? It sounds half like a normal Kato board - a plastic piece with two copper wires, one on each side, with the light bulb in the middle and copper tabs to the motor pinched under the wire. If this is what you have, then the Kato style decoders should work fine, although one ones I've done I soldered the wires to the motor rather than rely on clamping the flat copper tabs in the staples on the decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
For the older Kato SD40's, you want the DH165K0, not the DH165K1A. The 'K0 will replace your plastic strip-type board nicely.
The 'K1A is specifically designed for the new SD40-2 "Mid", and while it can probably be made to work in the older SD40's, there's really no need to go through the trouble. Just use the 'K0 instead.
HTH, Steve
davidmbedard Remember to solder wires directly to the truck phosphorus pickup tabs as the origional run of SD40 had pickup issues (this fixes it). David B
Remember to solder wires directly to the truck phosphorus pickup tabs as the origional run of SD40 had pickup issues (this fixes it).
David B
Make that, solder EVERYTHING. I hate those clip-on wires, both the ones with plastic caps and the kind that slip over the edge of the circuit board. Best case, one comes loose and the loco exhibts poor running, stalling on turnouts, etc. Worst case, it comes loose and touches somewhere it shouldn't, like a function output, and you blow the decoder.
The only benefit of the clip-ons is you can wire things up and try the engine out to make sure everything works OK - the engine goes forward when it's supposed to, the headlights go on correctly etc. - and then go back and solder the connections in place before reassembling the engine.
I had to totally disassemble the trucks and solder pickup wires directly to the sideframes in order to get reliable running. Kato's pickup scheme of the small tabs touching a bronze strip above the trucks was extremely unreliable and caused a sound decoder to continually shut down. Soldering wires to the trucks solved the pickup problem. I never use those slip-on plastic clips, but always solder the wires.
Thanks, guys. If I use the K0, what's your suggestion for the lighting, LED's, 12-14v lamps?
I used Yelo-glo LEDs from Miniatronics with 1K resistors, and cut back the light bars to fit. Each LED was attached to the light bar with shrink tubing. I've seen others that put two lamps (either bulbs or LEDs) in the middle with a piece of styrene between them which eliminates the step of cutting back the light bars.
Here is a tutorial I posted on your particular loco type earlier.
http://cs.trains.com/trccs/forums/p/148332/1645597.aspx#1645597
As I mention in the tutorial, I have done more than a dozen of these now. Let me know if you need more pictures or more detailed step by step info.
NOW you tell us you want sound!
Well, mine are silent, and I haven't had the shells off for a while, but I seem to recall some room in the top of the shell over the rear truck. A small oval speaker in an enclosure, firing down towards the truck, would probably work best. You'll have to re-work the rear lights. Hopefully someone who's actually put sound in one of these will chime in.
HTH,
Steve
Actually the SD-40 models never had pickup issues. The SD-40-2 models did have the pickup problem. The SD-40's and SD-45's use the same drive. The SD-40-2 is different. --- Ken McCorry
This is an old thread, but I have a question for anyone who may know...
When you hardwire these locos, is the motor isolated from the frame? Ie is it then safe for a decoder? Last thing I want to do is hard wire the loco then fry a decoder....
Yes, the motor is mounted in a plastic holder and doesn't touch the frame. Both motor brush contacts are at the top so they can clip to the circuit board. When I install decoders in these models I always slip heat shrink tubing over the brush contact strips to they don't touch the frame.
[quote user="cacole"]
Yes, the motor is mounted in a plastic holder and doesn't touch the frame. Both motor brush contacts are at the top so they can clip to the circuit board. When I install decoders in these models I always slip heat shrink tubing over the brush contact strips to they don't touch the frame.]|
Hey thanks for the answer. One more question though...Do you Solder in wires for the motor leads instead of soldering the motor clips from the factory?