Adding TTS Decoder to Rebuilt Merchant Navy

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markS&D
Posts: 221
Joined: Fri Oct 14, 2011 9:16 pm

Adding TTS Decoder to Rebuilt Merchant Navy

Postby markS&D » Tue Aug 06, 2019 10:28 am

As the title suggests, this is a write up showing what I did to add a TTS sound decoder to a Rebuilt Merchant Navy, my version of the model that I chose to fit the chip into is 'R2967, 35026 Lamport & Holt Line', which is from an earlier batch of models, that are DCC ready, but are not equipped to allow for the TTS system.

From the outset, I knew that this was not going to be an easy job, the DCC socket is inside the locomotive, and there is very little space available inside the loco body, fitting the supplied speaker was going to be impossible within the confines of the loco body see picture below
1.jpg
As you can see in the photo, I intended to fit the sound chip and speaker into the tender, I removed the DCC socket altogether just leaving the pickup wires and motor cables, my intention was to hard wire the decoder in the tender, and run 4 wires between the loco and tender.

Having unscrewed the tender weight, and removed the centre tender wheel, I placed the speaker face down inside the tender chassis, and drew around it, so that I could see where the chassis needed holes drilling for attaching the speaker, and to let the sound out.
2.jpg
The speaker fits nicely in the centre of the tender. Also, you can see that I have disconnected the pickup wires from the drawbar pin and top tender connection, they are taped up at the rear of the tender ready for soldering later, the wire at the top of the photo connects to the red decoder wire, and the one at the bottom, the black decoder wire.

I fitted the speaker using the screws provided, straight into the tender chassis making it a nice secure fit, and also at this stage, marked out on the tender weight where it needed cutting to allow the speaker to fit but still have enough weight to keep the tender on the rails!
3.jpg


Having cut the weight down, it can now be seen fitted into the tender chassis, there is room on top of the rear tender weight for the chip to sit on top.
4.jpg


As mentioned already, I was going to hard wire the loco to the tender, there is enough room behind the tender drawbar pin, to drill a hole for the wires to pass through. I had 4 wires, red, black, yellow and white. Starting with the locomotive first:

1: I soldered the red wire onto the red pickup wire on the loco chassis
2: the black wire onto the black pickup wire on the loco chassis.
3: I directly soldered the yellow wire onto the bottom motor connection and
4: the white wire to the top motor connection
5: insulated all wires with electricians tape

There is enough room to feed the 4 wires down and out under the locomotive cab, then you can reattach the loco body. I then fed the 4 wires up through the hole I had drilled behind the tender drawbar pin. I cut off the 8 pin plug from the wiring harness, and removed all extra wires from the chip just leaving the red, black, orange and grey wires and the speaker attached to the decoder.
5.jpg
Now it is a case of:

1: Solder the red wire to the red decoder wire, and to the tender pickup wire on the same side of the rails (the wire that was to the top on the earlier photo)
2: Solder the black wire to the black decoder wire, and to the other pickup wire.(the wire that was to the bottom on the earlier photo)
3: Solder the yellow wire to the orange decoder wire
4: Solder the white wire to the grey decoder wire

As already mentioned, the decoder chip will fit across the rear of the tender on top of the weight with room to spare, just make sure you insulate it from anything metal.
Test then refit the tender body.

Bit of a long winded post I know, but I hope this helps somebody.
My layout, only look if you are interested:

viewtopic.php?f=22&t=48422

Latest Video Link:

https://youtu.be/g5ytOK5FCZc

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RAF96
Posts: 637
Joined: Tue Feb 19, 2008 1:39 pm
Location: Dereham, Norfolk, UK

Re: Adding TTS Decoder to Rebuilt Merchant Navy

Postby RAF96 » Wed Aug 07, 2019 2:05 pm

I just swapped the provided speaker for a sugar cube and sat it on the shelf in the loco ahead of the socket.

IMG_0723.jpg
Last edited by RAF96 on Sun Aug 11, 2019 12:25 pm, edited 1 time in total.
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markS&D
Posts: 221
Joined: Fri Oct 14, 2011 9:16 pm

Re: Adding TTS Decoder to Rebuilt Merchant Navy

Postby markS&D » Sat Aug 10, 2019 10:36 pm

I get what your saying about the sugar cube speaker 8) I probably should have done the same, but I wanted to install the item as it is, granted it was a bit of an undertaking! I wanted to show what can be achieved with a little bit of forward planning for less than £40.

I have messed about with the CV settings of the Decoder, to try and get the thing to sound a little bit more in sync with the wheel rotations, but its not perfect, but for £33.50, I can live with it. My children love it. Despite what a lot of critics of the TTS decoder say, this one does have the nice 3 cylinder offbeat sound of the prototype, with authentic whistle sounds.

here is a link to a short video I took to show what it sounds like:

https://youtu.be/HwEA34lKUuI

Enjoy or not!
My layout, only look if you are interested:

viewtopic.php?f=22&t=48422

Latest Video Link:

https://youtu.be/g5ytOK5FCZc


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