Tuesday, February 3, 2015

TCS ASD4 in an Atlas Master Line GP7

About a year ago I presented an installation where I used a TCS M1 decoder on an Atlas Master Line GP7 which is intended to take a board type decoder but does have room for wired decoder using the existing PC board.  To see that post click HERE.  Recently I was asked to install TCS ASD4 board type decoders in several similar models so I thought it would be good to present that type of installation as well so someone could make the comparison.

What happens sometimes with these decoder board type of installations is that the contact tabs from the motor don't line up with the slots on the board.  The photo shows how I check for this, lining up the frame to board contacts first then checking alignment of motor contacts.

It's not hard to fix this problem by hard wiring the motor contact to the board.  I use scraps of orange and gray wire left from wired decoder installations.  It does not matter which color wire is used as long as the wire from the bottom brush goes to the forward slot and the wire from the upper brush goes to the rear slot just as the tabs would if they lined up properly.

Cut the tab from the lower brush short and solder a wire to it, then slide a short length of 3/32" heat shrink tubing over it.

For the top motor brush first remove the brush holder and take the tab off.  Then solder the other wire to it.  When cooled re-install holder with spring and brush into motor body.

After both wires are attached to the motor assembly, slip them through the plastic motor saddle as the saddle is pressed onto the motor.  When that's all done the finished assembly should look like this photo.

Another issue with the board type decoders is that they sometimes fit loosely in the frame.  On this one I fixed they by adding a small amount of solder to the contacts on the bottom side of the board.  On this model I found that a thickness of .030 was about right to get a snug fit.

Press the board into the right half of the frame, it should fit snugly. On these Master Line GP7 and 9 models, there may be a small plastic button.  That goes into the right side frame as shown here.

When everything is all put back together it should look like this.  The wires need to lay in between the frames.

A nice thing about this decoder board is that is has big solder pads to easily connect extra lighting functions.

In some future post I will show some ways to use these additional functions.