American Z Line RS/RSD DCC decoder installation

SJ Z-man Jan 14, 2021

  1. SJ Z-man

    SJ Z-man TrainBoard Member

    I have all of the possible DCC decoders to put into the spaces on the RS/RSD chassis.

    The Chassis is 6.9mm wide and the shell is the 'same so no sloppy areas on the side but that is not necessary.
    The DC Motor/Lightboard is 5.3mm wide, leaving 1.6mm total or o.8mm each side of the board. Most all Decoder wire is o.8-o.6 (for Digitrax and TCS, respectively) and o.54-o.50 for European Decoders. This allows the Decoder under the board to freely route to the needed locations for Track Power from the frame, Motor contacts and the Front and Rear LEDs (plus the Blue + wire).

    There are 2 Decoder pockets that are both 12.7mm long but the one at the rear is shallow at 2.2mm while the front is 2.92 deep. Since most all of the Decoders are 2.2 or higher, the Decoder needs to go in the front pocket.

    The DC Motor and Light board can be salvaged so allow easy Motor and Frame power pickups. The RS/RSD series uses a unique PC board so you cannot use the prior drop-in Decoders (Digitrax DZ123Z and TCS-DCC's AZL4 [1550]. The possible decoders narrow enough (the critical dimension) and short enough are:

    Digitrax DZ126T
    AZL Z2 [1296]
    ESU's LokPilot 5 Micro [59820]
    Doehler & Haass (Döhler & Häß) PD05A

    The latter is dang dong smaller, by far.
    Below are: DZ126T - Z2 - LokPilot 5 u - PD05a

    AZL 4 DCC decoder compare -shrink.png

    Attached will be a series of pix of using the TCS Z2, as it was narrower than the DZ126T, I had some to waste, and I wanted to test the Motor/Light board modifications (which I missed one but no harm), before I wasted time or unknowns get decoders from Europe (through US or Europe direct.

    Here is the Chassis with attached Motor/Light board and removed board, and modified:
    AZL RSD PC board notes.JPG

    The 2 big 'bulbs' are Inductors (a.k.a Coil, Choke) to eliminate Motor noise radiation into an ancient A.M. radio. Remove these to disconnect the Motor from the Frame by clipping them off. They DO NOT go through the board! They were just set in place and solder blobbed to a pad.
    The 2 large dark rectangles are Diodes that are connected to the track power for LED lighting and directional. Clip them off and then clean up the solder pads. The Blue wire will connect to this.

    I'll continue, after supper . . ..
    tjdreams and husafreak like this.
  2. SJ Z-man

    SJ Z-man TrainBoard Member

    Sorry for delay, N-scale wifie said something about a locomotive in a tunnel.

    Besides the component removal, you need to cut s or 3 traces to isolate the LED return and motor to the frame.
    AZL RSD Top side cuts.jpg

    To assure that the motor pickups don't touch the frame, 2 pieces of o.20 thick styrene, o.150 long, o.040" wide and place them between the motor contact and frame. Do not glue them in so that the motor can move as needed. (I had one motor pretty close to the frame).
    AZL RSD Motor isolation.JPG

    Next, fitting the Decoder and routing the wires. There assumedly is no space above the DC Motor/Light board and the inside of the Shell (as measured) but I have tested with Decoder wire on top of the board and the Shell goes all the way down to the Chassis bottom. This will be worst with the DZ126T wire and much lessor with the Euro Decoder's smaller wires. The DC Motor/Light board is screwed with M1x2mm screws. I used a M1x4mm to acted like a model post to help route wires before tacking them down.

    AZL RSD Wire routing-1.JPG AZL RSD Wire routing-2.JPG
    In the above side view, the 'S' light color wire next to the orange is the Gray Motor wire, not a white one.

    More later.

    I'll also have a dew decoder for potentially cleaner install and lessor price. The TCS Z2 [pn 1296] is significantly more expensive than all the others.
    Last edited: Jan 14, 2021
  3. rray

    rray Staff Member

    Nice work Jeff, thanks for sharing!
  4. SJ Z-man

    SJ Z-man TrainBoard Member

    Hmmm . . . I can't edit the post with the above 4 images. The Board Cuts is wrong (it as a mark to cut on top surface, which won't work). It was a prior image in the basket, should be this image: AZL RSD Top side cuts.jpg

    And while I'm at it . . the final wiring (first iteration). It is neater in the 2nd one I did. White wire beween boards.JPG

    Final wiring Right.JPG Final board Left.JPG

    Now, I am off to a different decoder that could make this easier !
    tjdreams likes this.
  5. SJ Z-man

    SJ Z-man TrainBoard Member

    Installed the smallest Decoder: Doehler & Haass PD05A. -3 gets you wired, -0 no wire. And that is a PD'zero'A

    D&H PD05A decoder overview.png

    Pix of Decoder are (shown front of loco, deepest pocket, standard DC board:
    D&H PD05A Decoder Pocket.JPG

    Pix with D&H installed:
    D&H PD05A Decoder Installed.jpg

    The great thing is it small enough to near direct to the 2 motor and FØF (white) ! Basically, only the 2 Frame power and rear FØR Yellow still have to go up top, like the others.

    D&H PD05A Decoder Motor & F0F.jpg

    D&H PD05A Decoder Motor wire.jpg

    I used their decoder wire however, the wires are so short that it is impossible to keep the PVC insulation from distorting. Order the PDØ5-0 and use Litz wire for these 3 and your scrap Red, Black and Yellow Decoder wire for the top runs.
    husafreak likes this.
  6. SJ Z-man

    SJ Z-man TrainBoard Member

    Looks like this when done: (Similar to others but better Decoder-to-Chassis fit)

    D&H PD05A Decoder Back.jpg

    D&H PD05A Decoder Front.jpg

    D&H PD05A Decoder Mount F.jpg D&H PD05A Decoder Mount R.jpg
    husafreak likes this.
  7. SJ Z-man

    SJ Z-man TrainBoard Member

    And: D&H PD05A Decoder Mount S.jpg

    D&H PD05A Decoder Right.jpg

    D&H PD05A Decoder Left.jpg
    husafreak, rray and drbnc like this.

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