New LokSound Direct Micro (73100) Install in SD45T-2

[tehachapifan]

I installed the new LokSound Direct Micro (73100) board in an IM SD45T-2. I'm happy to report that there was just enough room at the rear for a 9X16mm speaker with custom enclosure, although I trimmed the rear light tubes back to make a little more room. I have not attempted to add an LED at the rear or anywhere else yet, but it looks like it would be a snug fit adding an SMD LED at the rear...but probably doable. I did have to carefully pry the frame contacts open slightly more to accept the thickness of the board, which seemed to be a little thicker than the stock analog board and the slots were not allowing the board to insert easily. I knew that prying might cause breakage, but thankfully that didn't happen (YMMV). I also removed the foil-like material from the inside of the shell that I'm assuming is there only to block light(?). I'm not sure if this material is conductive but, to be safe, I opted to remove it just in case it made contact with the board as some of the components look they might get somewhat close. I figure I can add (non-conductive) black paint later if I need to block light. I also added Kapton tape to the frame where the motor contacts run, as the get very close to the frame there. I think one was even touching on my (previously analog) model.

[jdcolombo]

Good to know that there is room on the back shelf for a speaker.  I feared we'd be limited to fuel tank installs with these boards.  An 8x12 speaker would fit easily back there, but I'm also wondering: is it possible to flip the board around?  It looks like the back end of the board would fit in front of the black plastic cab spacer at the front of the frame, and the front of the board is shorter.  If it could be flipped, there would be more room in back for the speaker.

Might have to order one of these to see what is possible on an Atlas GP30 frame.  Sure makes the install a lot simpler!

John C.

[tehachapifan]

On this install, I am letting the motor contacts make contact with the pads underneath the board, which BTW are nice and big. I suppose if one was to solder motor lead jumpers to these pads, as been of course discussed before regarding more reliable contact, one could probably turn the board around as you suggest.

[jagged ben]

Good to know this can be done!  I too was assuming a fuel tank speaker install. 

[Steveruger45]

Nice fit.  Just wondering if you are getting any occasional sound drop-outs.  Even on good and freshly cleaned track, at slow speeds I occasionally get a sound drop on my OEM loksound IMRC sd40-2. I would  love to know where we could solder on keep alive caps on these new 73100 or the 73199 decoders as looks like room at forward to do so, but  I don't see any common ground connection pad on these.

[peteski]

I'll  post that info as soon as I get to look over one of those decoders. They do not have a dedicated ground (common) pad.

[tehachapifan]

I do get an occasional sound drop-out when the loco wheels or track start to get a little dirty. I know keep-alive caps are considered to some as a must, but I'm yet to install any. I may at some point, but I figure they sort of only delay the inevitable. My experience is that, once wheels or track start developing a dirty spot, it continues to collect gunk and worsen fairly quickly and I'm assuming would eventually get to the point where the caps wouldn't help any longer. So, I figure it's a matter of cleaning now or cleaning in a little while. Now, if these caps bought you a couple seconds of continued power, I would add them in a heartbeat but I'm under the impression it's only very brief....yes/no?

[peteski]

I do get an occasional sound drop-out when the loco wheels or track start to get a little dirty. I know keep-alive caps are considered to some as a must, but I'm yet to install any. I may at some point, but I figure they sort of only delay the inevitable. My experience is that, once wheels or track start developing a dirty spot, it continues to collect gunk and worsen fairly quickly and I'm assuming would eventually get to the point where the caps wouldn't help any longer. So, I figure it's a matter of cleaning now or cleaning in a little while. Now, if these caps bought you a couple seconds of continued power, I would add them in a heartbeat but I'm under the impression it's only very brief....yes/no?

Only the Keep-Alive circuits (which use very high capacitance Super caps in hundreds of thousands of micro Farads) will give few seconds of running time when power drops out. The ordinary keep alive capacitors included on the decoder, or even added by modelers, (in the hundreds or thousands of micro Farads range) only supply a fraction of a second power to the decoder.  But they do make running more reliable.

[jdcolombo]

I've found that 440uf of capacitance makes a huge difference in sound dropouts.  That amount won't keep a motor running for more than a few milliseconds, but with relatively clean wheels and relatively clean track, I get virtually zero dropouts.  One of the reasons I've been wary of the new boards from ESU is the difficulty of adding keep alive; Peteski will figure out how to do it though - he always finds the electrical truth

John C.

[Steveruger45]

Me too. 2 x 220uF seems to be the sweet spot from what I have learned so far.
Steve