Inside-Frame 4-4-0 - tender wires?

[tbdanny]

Hi everyone,

I've got one of the On30 inside-frame 4-4-0 engines, and I'm trying to fit a TSU-1000 decoder into it.  I've already bought the decoder, so I'd like to use it.

I don't think I'm going to be able to use the original PCB, as it takes up too much space with the decoder on top of it.  So I have two questions:

1) There are two plugs.  Am I correct in thinking that the two-pin plug is loco power pickup, and the four-pin is for motor and lighting?
2) There are two resistors on the PCB - green with coloured bands.  I'm guessing that these are for the locomotive headlight, and need to be hooked into the decoder's light outputs?
3) Are the other components on the board (capacitors, etc.) strictly necessary?

Cheers,
Danny

[richg]

Check the values on those two items you are calling resistors. Those are inductors. A very common misconception. About 4.7 microhenries; With the caps, they form a filter for a certain frequency that the decoder produces. Most just clip the caps so the inductors do nothing. Required across the Pond.
Good that you asked first. With DCC, never, ever assume. There are too many variables which you will eventually find out.

You might have to do a hardwire. The two lead connector is for the driver pickups. The four wire, two pins for lights and two pins for the motor.
Get your ohm meter out and do some continuity checks. Make a drawing. That is what I did.
If the loco has an LED, a 1k, 1/4 watt resistor for the LED.

Check carefully to see if everything will fit before removing the PC board.

Rich

[tbdanny]

Richg,

Thanks for the advice.  I did end up hardwiring the decoder.  Matching the orange lead from the decoder to the orange lead from the plug meant the motor turns the correct way.

I was using the wood load, and had to hollow some of it out, slightly, to clear the decoder.  But it was worth it  .

Cheers,
tbdanny