How Do I Select a Decoder for My Loco?
Will it Fit?
Is it Capable of Driving the
Loco Motor?
Primary concerns are size (will it fit?) and motor current capability.
Some manufacturers (Digitrax and Soundtraxx are two) feel that absolute
maximum motor current (stall at full voltage) is critical. Others (Lenz,
for one) don’t even specify maximum current, but look at operating
current. Personally, when I’m dealing with a loco, I like to measure
both the operating current and the maximum current and select a decoder
based on this complete knowledge.
Other Considerations
Secondary considerations are number of functions (and their current ratings), special lighting effects (called FX, EFX, XF), sound, and motor control (BEMF, quiet running, etc.), and cost.