I have installed two DH165KO (Digitrax) decoders in to Kato GP-35 locos. I have several Stewart F units that this decoder is applicable to. Question: can I leave the plastic "circuit" board in place using the existing screws that mount this part? It is not a circuit board in the usual sense, but rather a plastic part with fine wires with the truck wires coming up to it at each end and the headlight wires going into a metal tube where the bulb is located. This would simplify the installation without disurbing the headlight.....or is there more that needs to be done?
Thanks for help from anyone experienced with decoder installations in Stewart F3/7's.
-Al
This decoder is designed to replace that board. Prior to the newer Kato units with an actual pc board and LED lights, they all had that plastic 'board' with the two rods on the sides to link the truck pickups to the motor. On the Atlas/Kato RS series locos, there also was a single light bulb in the middle - the Stewart board might still have a small spot of metal in the middle whichw as a heat shield to the bulb wouldn't melt the palstic. The Kato decoder form factor is designed to repalce this board or the newer pc board and mount on the same clips.
Me, I just don;t deal with all that and hard wire the decoder in, using a basic decoder with wires, no special boards. Since the motor leads are seperate from the chassis, as are the track pickup wires from the trucks, they are very easy to do.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The 165KO completely replaces the Kato board this sits atop the motor. Save the original mounting screws, since they're used to attach the new decoder. You will have to solder the lights to the decoder, but otherwise the decoder board has everything you need. One nice feature of the KO is how it's set up for the Kato motor leads. Mount the decoder component side down, install the flat copper leads around the mounting "brackets" provided on the sides of the decoder, and attach them with solder. Other decoders require additional steps for attaching the motor leads.
Rob Spangler
Thanks guys. Now I have a related question: I opened up a Stewart F9......it is a later model apparently, because it has an actual ckt board which has an LED for a headlight. It seems to mount differently than the older "plastic" board with what looks like a 1.5 or 12V bulb. Looking closer at this set up, the DH165KO decoder doesn't look like it will mount the same as in the F3. There are two offset tabs that the board mounts to, and, there are no "motor clips" that mount under the KO "staples". There are two wires, black and red, that are installed in one of the three plastic connectors on the board. That opens another question, can the truck wires and motor wires be removed from those white plastic connectors without damaging anything?
Is there another decoder that is the equivalent of the DH165KO that is designed for this particular set up? or do I need to be more creative with the DH165KO? I like the 165KO because you can easily add a "Soundbug" sound system at a later date. Whew!.......sorry for the lengthy questions.
Thanks, again.
The circuit boards on the later Kato mechanisms (assuming there isn't a DCC 8-pin plug), can also be easily replaced with a 165 KO or 165 AO (the KO is basically just the AO with the extra parts added to allow the Kato motor and truck leads to be more easily soldered in place). Instead of wiring the flat copper motor leads to the KO "staples," you can just solder them to the tabs on the edge of the decoder intended for this purpose on the AO version. Electrically the two decoders are the same, and overall installation is almost the same - tabs take the place of screws, and the decoder board is dersigned to handle this as well.
All of my newer Stewart locos (Stewart drive instead of Kato) have 8 pin plugs. There's no need to use the DH165K0. There are numerous other options that have an 8 pin plug and will plug right in. The Soundbug will work with any decoder, it doesn't even have to be a Digitrax one. ALl it needs is track power, and that comes in via the two screw terminals. The 8 pins on the Soundbug are NOT the same as an NMRA 8 pin decoder plug, and don;t need to be connected for the Soundbug to operate.
Randy,
The board that is in my F9, has an 8-Pin socket labeled "J4". After looking through the Digitrax site, they have a decoder designated DH165IP. Could this be used in my case? It looks fairly small and there would be no need to do any extra wiring. Is there anyone out there that has this set up and has used this decoder? How do I tell the difference between the Soundbug 8 pin connector and the NMRA 8 pin decoder connector? This connector is an 8 pin that is actually a rectangular black receptacle. (J4).
The soundbug connector is only on Digitrax DH165 series decoders. If it's on a loco, it's an NMRA plug for the motor decoder.
The IP might fit - check clearances around the area to see if it will actually fit. The DH163P or DH163PS has the plug on wires so you don;t have to worry about it, plug it in and put the deocder whereit fits.
I wrote up a blog that details doing an Atlas with a plastic circuit board. The katos were very similar.
Older Atlas Decoder Install
Also, Kato has a good article on removing the board and replacing it with new light board.
http://www.katousa.com/consumers/HO-GP35-SD40-Circuit-Board-Conversion.html
Just to let you guys know, my dealer suggested a Digitrax DZ143P. It has an NMRA 8 pin connector with a short cable to the encapsulated decoder. It fit pretty good. All I had to do was carve out a small area in the ceiling of the shell just above the connector and its cable. Only took a few minutes and it worked out great! It doesn't have all the functions that larger decoders have, but I didn't need them anyway.Thanks for all your suggestions and advice.