I just finished installing LokSound Select Micro Direct (73100) decoders into Atlas GP30 and GP9. This thread documents the install for the GP30.
First off is a video of the finished unit. I simply throttle up/down, with ESU's Drive Hold on, to rev the engines without having the loco move. At the end of the video are the install pictures discussed below
The GP30 is a DCC ready frame, and one which the 73100 ALMOST works right out of the box! Just a couple of "gotchas" to watch out for.
Here is a full view of the install
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You can see the custom enclosure I built for the speaker for this unit. The frame does need some milling, but not, as expected, in the back for the speaker. Instead, the channel over the motor needs to be widened. Besides my liberal use of Kapton tape, the two areas on the left, where the frame extends over the board, need to be cleared. If not, the frame can contact components (or even knock them off).
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This photo shows the area where I milled (pink boxes)
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You will also note two motor wires going to the motor contacts on the upper side of the board. On this specific loco, the brass strips coming from the motor were not in the best of shape and would not maintain contact. So I simply solved the issue by soldering wires to them, and then to the board. I also put some solder blobs onto the two frame pickup pads of the decoder which are under the large frame pads on the right. Speaker wires are the brown wires.
Next is a close up of the rear and custom speaker enclosure
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Made from 0.020" styrene, the enclosure provides sufficient interior volume for the Soberton 8x12mm speaker. The enclosure's width is 0.357", and the height in the rear is 0.185". The length of the deep part runs 0.75 inches, with a 0.090" step to another 0.25" of length on the "porch". If one looks closely, between the enclosure and the board, just to left of the speaker (and large square chip), there is a 0.020" shim of styrene, which keeps the decoder and speaker apart.
I used a warm white 1206 SMD LED for the rear light.
Finally, as can be seen, there really is no room in the front for a regular LED, so instead of soldering another SMD LED, I used the on-board Aux-1 0402 SMD LED as the front headlight. Works just fine, as seen in video.
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