Installing a Digitrax DN163K0a decoder into a Kato DF 200-50

[alpineaustralia]

Below is a pictorial on installing a Digitrax DN163K0a decoder into a Kato DF 200-50.

 

1. Take off the shell by running your fingernails along its outer edge. Once off, you will see the light board with its SMD lights (ee Photos 1. and 2.)

[alpineaustralia]

2.  Remove the light board by removing the little grey clip and sliding the lightboard the along its axis until it is free of the grey recessed holder that holds it in place and up.  You will see that the motor contacts are short and sit underneath the light board rather than come up over the sides like other Kato locomotive models.  This makes the installtion simpler because the contacts do not come into contact with the copper pick up rails and will not need to be isolated.  They will contact the decoder on the two small copper pads on the underside of the decoder rather than on two larger pads on top of the decoder like other Kato locomotive models (see photos 3)

 

3. Place the light board alongside the decoder to get a sense of how short to cut the LED stalks so that the decoder fits within the same length as the original light board (see photo 4.)

[alpineaustralia]

4. Cut the LED stalks down to size. To ensure that the LEDs are re-installed with the correct polarity, I cut the stalks at an angle so that there is no mistake as to how the LED should be re-installed (see photos 5. and 6.)

[alpineaustralia]

5.  Solder the LEDs back onto the shortened stalks (see photo 7.).

 

6. Install, the decoder by putting it in place of the decoder and replacing the clip. Make sure you place it in the same orientation as the original lightboard. The easiest way to know that you have done it the wrong way is that the clip will sit over componentry rather than on the shiney clean copper part of the decoder, as is shown in photo 8. 

[quinntopia]

Wow.  How timely is this! I should be getting one of these in the mail any day (and already have the decoder!)! I'm really glad for this as I just know that the lengths of the LED leads on the decoder would have caused me to 'panic' (well, not quite panic, but I would not want to start cutting up a decoder if I wasn't 100% sure that it was the right thing to do! Some of this is not necessarily intuitive for 'DCC- ready'! :-)).  Thanks!

[alpineaustralia]

No problems mate. There are two tricks:

 

1.  is to ensure that the decoder is oriented in the same way that the original sound board. Please note that the photos shows the decoder wrongly placed, rather than correctly placed.

 

2. To ensure that the after you have cut off the LEDs you install them with the correct polarity as they were on the decoder before being cut off. That is whay I clip them at an angle to avoid being confused later on.

[CaptOblivious]

Alpine, nice work. Cutting the LED stalks like that is an interesting move. I usually desolder the entire LED, trim the soldery-bent-up ends off the stalks, reinsert them and bend the stalks at a new location so that the length of the LED is right, solder it back in place, and trim off the excess.

 

Desoldering the LEDs is not particularly dangerous to the decoder, but is kinda tedious (desolder wick is essential).

 

This looks quite a bit easier, and I doubt that weaker joint produced by your method really matters in this application. How hard did you find solder the LED back on?

[quinntopia]

Alpine... a question on this install.  :)

 

You will see that the motor contacts are short and sit underneath the light board rather than come up over the sides like other Kato locomotive models.  This makes the installtion simpler because the contacts do not come into contact with the copper pick up rails and will need to be isolated.  They will contact the decoder on the two small copper pads on the underside of the decoder rather than on two larger pads on top of the decoder like other Kato locomotive models (see photos 3)

 

As I'm reading the Digitrax instructions and following your post, I'm a bit confused.  Did you isolate the electrical contact rails (the copper strips that run along the sides of the chassis) with Kapton tape near where the motor contacts are? I can't tell from your photos if you did use tape to isolate or not.

 

It appears that this needs to happen according to your post, but that could be a typo, and as the Digitrax instructions give some specific areas where the Kapton tape should go (albeit for an Amtrack loco, which as you mention, this engine has a different set up than other Kato locomotives), I'm a bit confused on where/if the Kapton tape is applied!

[CaptOblivious]

Normally, the brass tabs from the motor stick up from the engine's innards, outside the brass rails, and fold over the rail to make contact with them—that's how the engine gets power. So you put some tape around (not just on top, but all the way around!—it's actually the edge of the rail that poses the greatest danger of a short!) the brass rails where they meet the motor tabs. That way, the motor tabs only make contact with the special contact points on the decoder, and don't short out on the brass tabs.

 

However, as Alpine mentioned (and this is interesting…), this loco doesn't work that way. Look at Alpine's third photo, and you see the motor tabs stick up, not outside of the rails, but inside of them, and are already isolated by bits of plastic. How handy! No Kapton tape necessary, no risk of a short.

[alpineaustralia]

This looks quite a bit easier, and I doubt that weaker joint produced by your method really matters in this application. How hard did you find solder the LED back on?

 

I used to do this but a few times now I found that I applied too much heat to the decoder and as a result the light wouldnt work. I instead opted for this because it is easier, safer and I could unsolder it, cllip off a bit more stalk and resolder if I got the length wrong. In terms of weakness, there is no pressure brought to bear on the LED and so there has been no occassion for the light to fall off.

Total time about 5 minutes.

 

Did you isolate the electrical contact rails

Capt answered this correctly. I didnt have to isolate the motor contacts becasue they are already isolated. I  apologise. My post should have read "do not need to isolate" rather than "need to isolate". I will correct it shortly.

[quinntopia]

Great!  Thanks for the responses, that was a very easy install!  Everything is working great! Well almost, I have another issue.....(unrelated to the install)

[David McC]

An update now that the Kato Seven Star Cruise Train is out.

Digitrak has a DN163K0d decoder which has short LED leads.

It's identical in function and layout to the DN163K0a

It is a direct drop in - no tape or modifications needed.

 

 

[chadbag]

I installed a TCS K0D8-A into my 7 Stars DF200 tonight.  Works great!   First time I have installed a board replacement type decoder.  Gives me hope for the future.

 

I'll post some pics later but it was really easy.   The TCS K0D8-x are all variants of the same decoder and are used in the same applications as the Digitrax DN163k0x decoders.  The difference between the variations are the LEDs (or lack thereof) that are preinstalled.  I had 3 different K0D8-x models on hand:  K0D8-A (which looks like the Digitrax DN163K0a with the really long LED leads), K0D8-D (no LEDs preinstalled -- add whatever you need), and K0D8-F (has one long LED on the front, none the back).

 

I used the K0D8-A since I did not have any extra LEDs to add to my -D model.  I de-soldered the LEDs, cut them down to size (by comparing against the KATO board) and soldered them back in place.  The motor power tabs are quite short on this one and need to be longer to wrap around to the top of the decoder (unlike older locomotives that had longer motor tab strips).  I soldered some wire extensions to the motor tabs (and melted a little of the plastic motor mount in the process ), mounted the decoder, pushing the motor tab wire extensions up through the middle of the decoder, and then cut the wire extensions down to size and soldered them to the top of the decoder.

 

I put the locomotive on my programming track -- it could read all the CVs -- and gave it the address 2007 (200 for DF200 and 7 for Seven Stars).  Then I put it on my layout, got WiThrottleLite on my phone and put in the address for the locomotive, and was able to drive it around both directions, with and without lights, just fine.  Works great.  I'll post pics in the morning of what I did but it was easy.   I would assume using the Digitrax or KATO/Digitrax decoders would be just as easy to install.

 

I have not added decoders to the directional lights of the wagons etc.  Yet.

 

ETA:  

I have a KATO 7007-3  JRF  DF200 and it looks identical inside to the 7 Stars and very very similar to the one in the tutorial above.  I'll convert that tomorrow using another TCS decoder as my son is complaining that all the freight locomotives I have with DCC are German ones and not Japanese (most of my Japanese trains converted so far are ones that take an EM13 plus the KATO 800 Shinkansen and a Tomix N700 (JR West / Kyushu) that I soldered one in.   Most of my German ones so far have had sockets so are way easy to do which is why the German ones outnumber the Japanese ones so far).

 

Anyway, the TCS K0D8-x (I used the -A) is a viable alternative to the Digitrax and the process is pretty much the same as listed above

 

Edited January 23, 2019 by chadbag

[chadbag]

Here are the photos:  

 

The DF200 (7 Stars) with the top removed:

 

The KATO light board top and the TCS K0D8-A bottom:

 

 

Same boards with the K0D8-A shortened LEDs

 

 

The next two images show the locomotive without board and then the underneath of the K0D8-A.  The motor power tabs are the two small copper tabs between the left flywheel and the motor.  They are not very long.  The underside of the TCS decoder shows no places for the motor tabs to interface with the board.  And the tabs are not long enough to wrap up around.  This is why I soldered some wire on to the tabs.

 

 

Completed board installed in locomotive showing the wire from the motor tabs wrapping around and soldered to the decoder.

 

Final image showing completed project.

[chadbag]

I just did my Red Bear 7007-3 DF200 using the same model decoder and the same procedure.  Worked like a champ.

 

[Arlo]

Thank you for all of the great information. I look forward to getting my Decoder ordered so I can get this up and running. The pictures really help as well as all of the other information that people provided, Doesn't seem nearly as intimidating a project now. Thanks again and really glad to have a place to share ideas now.