I have had  the drive Axel gear on both my spectrum 4-6-0 and Cornie crack and separate under very minimal use. Bachmann's solution appears to be a new Axel and wheel and gear set , but even that they are out of stock.  I sure hope the NWSL site works.  On the Mogal I was able to reinforce the gear with copper bands so now it is operational, but not the Cornie.

I'll answer my onw first question. After reading a few months of past questions and answers, the answer is YOU CAN"T USE THE OPTICAL CHUFF SIGNAL. I should just glue some magnets to an axel and use a reed swich. So much for the improved electronics. I do however love the track battery switch to isolate the power from the track.

Just received my K-27 a few days ago. The Dummy Plug has J1-5 for Chuff input. However ,the sound system that I normally use is Sierra Sound which expects two chuff wires to be closed to complete a loop. What is the contact for the second chuff sound wire?. Actually I tried all of them, but none worked.  This may be related: My K-27 came with two shinny black disks in a small plastic bag. No mention of these disks appear in any of the written material or diagrams. What are their purpose?

I did and he did. Essentally my plan will work, the two extra wires are power to a non existant tender light.Also my axle is the wrong one.

I want to put R/C in the spectrum mogal, but use track power. There is an obvious collection point under the bottom plate. Two wires of the  four wire lead to the tender picks up tender track power. The other two leads are not connected. What are they for?

I had thought of disconnecting the two leads from the collection point in the engine to the electronics and using the two "extra" wires to the tender to pass engine track power to the tender. Combine that with the tender pick-up and then pass all of that through the R/C and sound board. Then send the motor power back along the lines that were connected to the tender pick-ups. I don't know if the wires will handle the moter load, and there must be some use for the two extra wires.  Also the chuff pick up on the last axle  is always on. There is no break in the metal axle contact. What doe one usually use to break the contact?

A few years ago I read an article on how to convert the spectrum shay to R/C battery control.  I did this using an old R/C set I had.  It worked fine. and  I would not have thought to isolate the track by removing the BBs that transfer the power from the wheels to the chassie.

Question. Does anyone know of similiar articles for the spectrum 2-8-0 and the Spectrum 2-6-0 mogal?  This time I want to keep the track power as my layout is indoors, but I need to impose R/C speed, power, and sound control.