RS-11 Sound Install Tutorial (with photos)

[jdcolombo]

As I promised some of you, here is a complete tutorial on how I install sound in an RS-11.  The process for the GP7/GP9 is the same - even the frame milling is almost exactly the same.

The first step is to prep the speaker by building an enclosure around it.  I've already covered how I do this in another post.

The next steps involve preparing the shell.  I do three things to the shell.  First, I trim back the plastic numberboard/headlight inserts to open a bit more space at the ends of the shell - this better accommodates the speaker.  The following two photos show the original insert, then the trimmed insert:





Next, I thin out the front of the shell just a bit using a 1/4" drum with a 250-grit sanding drum on a Dremel.  The stock shell has about 10.3mm of space inside, and the LokSound is 10.6mm wide; so I thin the shell by about .3mm (I use digital calipers to measure, but you can use the decoder to test the fit). Photos:







Next, I use a #80 drill bit chucked in my Dremel to drill holes in the fan grille at the rear of the shell for sound egress.  I drill holes between every other "slat" in the grille (on the GP7, I drill a hole in between each fan "blade" in the two rear fans).  The holes are so small that you don't notice them after they are drilled (particularly after I dry-brush the fan with some grimy black paint), but they let out a lot of air.  Here's a photo showing the holes from the inside of the shell:



OK.  Now it's time to prep the frame.  In order to accommodate the speaker and the decoder, you'll have to mill the frame a bit.  The following photo shows the areas in black that need to be milled off each side of the frame:



Be VERY careful when cutting/milling around the motor mount hole at the top of the frame and around the cutout for the flywheel - too much cutting here and you'll cut through the frame (ask me how I know this).

After you are done, you'll want to insulate the area of the frame where the motor contact strips come up to contact the circuit board.  I use kapton tape for this.  We won't be using the circuit board, obviously, so you want to make sure these strips can't accidentally contact the frame and cause a short:



Here's a series of three photos, showing the cut frame; where the speaker will go on the rear of the frame, and the frame reassembled with the motor inside and the kapton tape insulating the areas where the motor contact strips are.







The last prep step is to cut a small piece of the old circuit board to use as a place to solder the decoder power pickup wires to.  My RS-11 had an old Atlas decoder board in it that I scrapped, but you can do the same thing with the standard light board:





That's it for all the prep steps.  In the next part of the tutorial, we'll install the decoder, headlight LED, and speaker.

John C.

[jdcolombo]

Now that all the prep work is done, time to install the various components.  Here's a photo of the RS-11 without it's shell next to the LokSound:



The first thing I do is cut the LokSound wires to the right length.  The exact length will depend a bit on the exact placement of the decoder on the frame, but the orange wire is about 20mm; the gray about 22mm; the red and black about 32mm.  Then I strip the ends of the wires and tin them with solder:



Now before installing the decoder, I put in the surface-mount LED that I'll use for the front headlight.  I use a sunny white SMT LED from Richmond controls that come with 6" fine magnet wire attached.  This will need to be trimmed - you want just enough of the wire to loop at the end of the "channel" in the top part of the frame and hook to the white and blue wires.  After you cut the wires, you'll need to figure out which one is the Cathode (+, to blue wire) and Anode (-, to white wire).  I do this by unwinding about a half-inch of the wire, removing the insulation by running the wires through a blob of hot solder (which also tins them), and then using a 9v battery and a 1K resistor to test which wire is which.  I hook the resistor to the negative post of the battery, then hold one of the LED wires on to the end of the resistor while touching the other wire to the positive battery terminal.  If the LED lights, you know which wire is which.  If it doesn't, reverse the wires, and now it should light (if it doesn't light at all, you might have a defective LED, though I've never had a defective one from Richmond Controls).  Here's a photo of the LED installed:



Note that I don't use a rear light - that's only because I run my diesels in consists of 3, meaning that I always have one engine facing each way, and accordingly I only end up using the front headlights.  So I don't install a rear headlight, just to save some time and complication.  But you could use the same technique for the front headlight and install a rear one if you want.

Now it's time to install the decoder.  First, I solder the motor wires.   The gray wire goes to the top motor brush; the orange to the bottom (you can identify which is which because the contact strip for the bottom brush wraps around the side of the motor):



Though the photo shows the decoder taped to the front of the frame, I solder these two wires BEFORE I tape the decoder to the frame.  Then I tape the decoder in place with a piece of kapton tape.

Next, I solder the red and black power pickup wires to the small piece of circuit board:



Next, I solder a 1K 1/8 watt resistor to the blue wire, then solder the LED wires to the white and blue wires respectively.  I use heat shrink tubing to insulate the wire joints (1mm heat shrink tubing on the white wire; 1/16 tubing that slips over the resistor and insulates both ends of the blue-resistor-LED wire connection).  Unfortunately, I forgot to take a photo showing the resistor soldered to the blue wire, but here's one of the final result (you might have to zoom in to see the blue wire and then the "bulge" of black heat shrink tubing):



At this point, I put the trucks back on the frame, and test the installation on my layout.  I want to make sure there isn't a short; that the motor runs and that the headlight works (it did).  Then I do the speaker installation.  I use gel CA cement to glue the speaker to one side of the frame to keep it in place.   Then I solder the speaker wires to the brown decoder speaker supply wires, and again insulate the joints with 1mm heat shrink tubing:



The last step is to put a small piece of kapton tape over the wires to keep everything in place:



Then I test the completed installation on the layout:



When I'm sure everything works, I put the shell back on.  Now it's time to program the decoder with the 4-digit address, the right horn, adjust sound volume, etc.



The whole process takes me about two hours now that I know how to do it.  If you try this and need help, feel free to e-mail me directly at jdcolombo@gmail.com

John C.

[skytop35]

Most excellent John! Thanks for posting this.

[jdcolombo]

Updated tutorial to reflect that while I don't install a rear light, you could easily do so by using another SMT LED in the rear behind the speaker.  The wires will easily slip under the speaker between the frame halves (cathode to blue; anode to yellow).

John C.

[Kentuckian]

This should make the sticky notes!

[keeper]

Most excellent John! Thanks for posting this.

+1

Now part of my bookmarks!

Thomas 

[peteski]

This should make the sticky notes!

...or even the "best of TRW" section.   

In the least, it really belongs (as a sticky) in the DCC section of this forum.

[jdcolombo]

Here's a photo of about the only different thing when doing a GP7/9 sound install: the holes drilled in the fan detail at the rear of the shell:



The GP7/9 shell is also a tiny bit narrower - 10mm, instead of 10.3 for the RS-11, which means you need to do a bit more judicious sanding on the inside of the shell to get the LokSound to fit. 

John C.

[cnw mike]

John, not sure if you caught my note in the speaker enclosure thread but the fox speaker is set to be discontinued the first of the year.

[BCR 570]

Thank you for posting.  I was a little disappointed to read that the shells have to be thinned in order to fit the decoder.  In researching this I had been worried about fitting in the speaker and I now see that the LokSound decoder is 10.6mm wide.  The Atlas/Kato RS-3 and RS-11 shells are about 10mm inside, but the other locomotives I would want to fit these into are even narrower.  What is really needed is a programmable decoder about 9.5mm wide.

Tim

[jdcolombo]

Thank you for posting.  I was a little disappointed to read that the shells have to be thinned in order to fit the decoder.  In researching this I had been worried about fitting in the speaker and I now see that the LokSound decoder is 10.6mm wide.  The Atlas/Kato RS-3 and RS-11 shells are about 10mm inside, but the other locomotives I would want to fit these into are even narrower.  What is really needed is a programmable decoder about 9.5mm wide.

Tim

Hi Tim.  Yes, I really wish the LokSound were narrower.  In fact, a company called CT Elektronik from Austria makes a programmable sound decoder called the SL76 that is 16.6mm long by 7.7mm wide by 2.3mm high.  Unfortunately, they do not have any US-prototype sound files available, and I don't speak German; we need for someone to do with them what ESU LokSound did - find a reliable U.S. partner to develop U.S. sound files and market the decoders reliably.

Another possibility is this: Atlas is apparently using LokSound for the sound decoder in the new Atlas S-2 switcher.  That thing must be tiny.  I wonder if ESU might adapt it to a broader array of installations . . .   

One final possibility is to try to install the LokSound at an angle to decrease the width needed.  I could imagine milling one side of the frame at an angle to accommodate, say, a 30-degree tilt.  I haven't tried to engineer anything like this, but I might take one of my old diesel frames and see what would be possible.

John C.

[garethashenden]

Have you noticed any change in the pulling capacity?

[BCR 570]

John:

Yes, I had wondered about an angled installation to reduce width.  I think that given the number of narrower diesels whic hcould use the LokSound decoder, it might be worth contacting them to see if they might be able to engineer a slightly narrower version.

Do you anticipate being able to test and review that new speaker prior to the Knowles Fox being withdrawn?

Tim

[jdcolombo]

John:

Yes, I had wondered about an angled installation to reduce width.  I think that given the number of narrower diesels whic hcould use the LokSound decoder, it might be worth contacting them to see if they might be able to engineer a slightly narrower version.

Do you anticipate being able to test and review that new speaker prior to the Knowles Fox being withdrawn?

Tim

Well, maybe if we both write them, they will listen - the Europeans seem to have a soft spot for N scale given their relatively modest housing sizes; I'm surprised LokSound hasn't already tried a smaller version to compete with CT Elektronik and also Zimo, which I think has a decoder that is 9mm wide.   Even if they did a bit less (I think the CT has only 3 sound channels, instead of 10 or whatever the LokSound has), I could live with it if it keeps the terrific motor control and gets the main sounds (bell, horn, prime mover) right.

I have some of the Star Micronics 8 x 12mm speakers coming tomorrow.  I'll need to build an enclosure around one, and then I'll test it side-by-side with the Fox using a spare ESU decoder I have (waiting to go into an SD9).  I wonder, though, if Knowles is planning on a replacement for the Fox.

John

[jdcolombo]

Have you noticed any change in the pulling capacity?

No, but I run my diesels in 3-unit consists pulling 30-car trains on a ruler-flat layout, so I'm not likely to notice.  I will say that I really don't remove that much metal from the frame - it looks like more than it is.  You could probably easily replace any lost weight by using a bit of tungsten putty in the cab sides, if you wanted to.

John C.