Motor Coach Kit: MX648; SugarCube7; LifeLink + 2x 470uF Flat Tantalums
Eagerly awaited, the Kato Class 800 Hitachi in N gauge has arrived! Typical Kato build quality, and running on DC is superb -
reliable and silky smooth.
However, converting to DCC has never been made easy in Kato's models, and 800 is no exception sadly. Although there are
dedicated decoders available specifically for it, in a 3-piece set, giving a function decoder at each end for lighting, and a
motor decoder in the power car, but they are a bit fiddly and non-standard in connection.
Adding DCC sound is also possible through a dedicated decoder, but again, it is not a case of quick plug-and-play
unfortunately.
We decide to take the approach of hard-wiring for sound, using a good old Zimo MX648. There is space at one end of the coach
for a good speaker and the decoder with stay-alive at the other end, with all kit hidden behind just the doors, so nothing
visible through the coach windows.
A finger nail along the coach body allows it to be removed quite easily. Inside we can see how neat the mechanics are - all
hidden below the seating level.
Unclip the seating mould reveals a solid metal flat plate, and unclipping the underframe plastic mould reveals a good motor
with dual fly-wheels. The pickups are strips running the length of the coach, using both bogies.
As a DC model, it is excellent, but in order to convert to DCC we need to get in between the pickups and the motor. A shaped
spring clip goes over the top of each motor terminal, with the sprung end pressing down onto the pickup strips either side, so
we simply need to insulate that spring clip and insert our decoder connections between them.
Remove the spring clips carefully with some tweezers, solder some fresh (and quite long) wires (orange and grey) to them, and
insulate the sprung end with heat shrink.
Tin the pickup strips with a small amount of solder, ensuring it is a fairly flat patch either side, and attach fresh red and
black wires, which will go to the decoder for pickups.
Put the spring clips back into position and carefully feed all 4 wires up through the closest motor securing hole in the metal
- you'll need the motor slightly raised away from the metal in order to find space to thread them through. It is a bit fiddly,
but be steady and patient - there is enough space!
With everything fed through, press the motor back down into position - might require a little jiggling, and it likely won't fit
completely flush with the clips through the metal plate, but this doesn't matter as long as the motor still drives the shafts
freely. You can test this on DC by joining orange+red and grey+black wires temporarily.
Drill a hole through the floor of the seating, large enough to comfortably feed the 4 wires up through.
A SugarCube7 is a great fit at one end, fixed down with a small blob of BlackTack.
At the other end, we need to remove a couple of the uprights from the seating plastic to make enough length for the MX648
decoder, but this is all hidden behind the doors, and not visible through any of the main windows.
Next we solder the pickup and motor wires direct to the decoder (having removed all of the original wires from the decoder).
This allows us to get the length just right, and to avoid unnecessary joins. Of course, if you don't mind the wiring being
visible in the seating area, you can simply join the wires up - there's plenty of space in there! Note that we have a short
blue and grey wire too, which will be for connecting a stay-alive.
Rather than glue the wires down, we just use some double-sided tape down the centre aisles.
For the stay-alive, a LifeLink with a pair of flat 470uF Tantalums will be quite suffiicient - the model is already quite good
on the pickups, but of course, every little extra help is good!
Some black electrical tape to cover the door windows, so the kit is hidden.
Everything back in place, including the ceiling light duct (which we haven't taken advantage of in this install).
Mix some grey paint to match the seats, and paint the wires.
Quite a comfortable fit after all, with the coach body back on.
End Car Kit: MX617 wires; LifeLink + 2x 470uF Tall Tantalums
Next we tackle the end cars, to give DCC control of the directional lighting. Once again, there are specific decoders designed
for this purpose (if you can get hold of them), but we decide to use the more readily available MX617, to which we can also add
a stay-alive.
Unclip the end car from the non-nose edge, dropping the chassis out, then pulling away from the nose. It comes out quite
easily, though the nose hood and skirt do fall out quite easily once the chassis isn't in place!
Remove the spring contacts from each side with some tweezers, then carefully take out the lighting PCB. The underside switch
will be redundant under DCC (cream colour plastic piece), so we can remove that and discard it.
There are 4 contact pads at the end of the PCB which give us connection for the white light and red light. The rear-most pads
are for the white light, and the next pair in are for the red light. There is a protective resistsor for each LED on the PCB
already, so we don't need any other components for the lighting - simply solder our common positive (BLUE) wire to the 2 common
pads, then the decoder's white to the negative for the white LED, and the decoder's yellow to the negative for the red LED.
Once wired up, we cover the contacts with Kapton tape, as we don't want the pickups shorting onto them now!
Our MX617 decoder is a full motor decoder, but there is no motor here, so the grey and orange wires are not required. We could
have used a dedicated function decoder, such as an MX681 or MX671, but didn't have any to hand, so the MX617 did the job just
as well for us instead!
Note how we added another grey wire for the GROUND connection of our stay-alive, and an additional BLUE wire for the positive
of the stay-alive.
Here we see the lighting PCB back in its' original position.
The decoder's RED and BLACK pickup wires are soldered to the spring contacts we took out earlier, and inserted back into their
original position. This helps to hold the lighting PCB in position.
Next we wire up the stay-alive, which is a LifeLink PCB and a pair of 470uF Tall Tantalums joined in parallel. The position of
each component is important as the seating mould has vertical supports that go between them, so we just need to line things up
accordingly. Where the decoder is positioned, there are a couple of tiny support pillars under the pickup contacts strips -
these need to be snipped back to allow the decoder to sit fully flush on the floor, but otherwise it is quite simple to place
these parts, and the body goes back on easily afterwards. Small blobs of BlackTack to hold the components into position.
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