This installation of TCS MC2 digital decoder is for HO-Scale Atlas Alco HH660 and was performed by Craig Zeni.
Shown with the shell on prior to installation.
The body shell is held in place by t6he couplers. remove the screws and couplers boxes, set aside. The body lifts straight up with a little wiggling. Do not pull too far as the cab light wires stay connected to the light board.
The model with the shell off, nothing done. The eight pin NMRA DCC plug is circled in red. Lift it straight up to remove it.
The model with a TCS MC6 decoder installed. I used a blank male NMRA plug and solder the decoder's harness wires to it myself. This is not difficult to do if one uses a small soldering iron, good flux, and solder, and a heat sink on the pin side of the plug - I use a fined nosed hemostat. This keeps the plastic from melting. The harness itself is about 1.5 inches long I used the MC6 because that's what I had on hand. If I was doing it from scratch I would use an MC2. There is not enough room for a T1. When refitting the body, take care to get all the wires out of the way. They like to bunch up on the top of the circuit board and keep the shell from sitting all the way down. Also, there are small projections under the walkway that fir into recess on the frame. Gently squeeze the walkway to get these pins to line up properly.When installed properly, the bottom of the frame will be leveled with the bottom edge of the walkway.
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire