N scale decoders for athearn sw-7 ho scale engines???

[Anonymous]

I am wondering what N scale decoder I should use for athearn sw-7 and s-12 engines? Also what decoder should I use for ath. dd40 engines with 2 motors?

[nfmisso]

Call Tony's

http://www.dcctrains.com/

[railman]

that's a good question with the DD40's....has anyone ever talked about the dual motors? I'd imagine it's been done...

[cacole]

I used a Lenz LE077 decoder, which is about the size of a dime, in two Kato NW-2 models. This was sold as being for both HO and N scale, and I have had no problems with it. The Athearn may draw more current than the Kato model, especially if you're talking about the older Athearn Blue-Box locomotives. The DD-40 is going to require at least a 2 Amp decoder, or two separate decoders; one for each motor but set on the same address. I used a Digitrax decoder for mine, but I don't remember the decoder type. As nfmisso suggested, give Tony's Train Exchange a call and they can tell you exactly what will fit in these. Decoder manufacturers all recommend that you first determine the "stall current" of a locomotive to know what decoder you will need. The way to do this is to put the locomotive on a track connected to a standard power pack and Ammeter; turn the throttle to full speed, and push down on the locomotive until the wheels stop spinning. The Ammeter reading is then your "stall current." I have found this to be a rather ridiculous and meaningless practice, however, because that's not what I will ever be doing to a locomotive in actual use. If there is a heavy enough load on the engine, the wheels will spin, not stall; and once they begin to spin the current draw will be less. I think decoder manufacturers just came up with this as a way of insuring that a decoder would never be overloaded and burn out. I have successfully used lower-rated decoders with no problems.