Installing a sound decoder - 6
I’ve done all three. At this point a four-wire cable between the
engine and tender may not be enough, and the TCS six-wire
cable would be a good choice if you plan to use any additional
lighting functions like a Mars light or Firebox Flicker. In any
event, two wires will go to the headlight and two to the motor
plus one wire for each additional function and/or right-hand
rail power from the engine frame, so this is the time to plan
what size cable you will need.
It is important to make a drawing of which wire goes where in
the cable. The black decoder wire will go to the tender frame/
floor. You can put the headlight dropping resistor in the ten-
der as well. Again, if you desire lighting effects in the engine in
addition to the headlight, mounting the decoder in the engine
might make things easier.
CAUTION!
Hard-wiring functions between the engine and ten-
der without a disconnect plug is considered bad practice and
shoddy workmanship.
A decoder installed in the tender should be held in place so it
doesn’t flop around during handling, and possibly damage the
speaker or connections. It can be taped to the floor in the coal
or oil compartment away from the speaker using double-stick
tape or plastic electrical tape.
I’ve made retaining clips out of cardboard to hold the decoder
up against the underside of the tank, yet made it easy to
remove if necessary. Since a Tsunami gets fairly warm while in
use, avoid making a retainer out of plastic – the heat will warp
it. Cardboard will withstand the heat and keep its shape.
Testing and wiring the decoder
At this point you should unpack your decoder, sit down, read
the instruction sheet and then come back to this section. While
I’ve only had one DOA decoder in 15 years, we should still test
the decoder before we proceed with the wiring. You will need
to have clip leads from your DCC track power handy.
With the decoder wires untangled, strip off the insulation from
the red, black and the two purple wires; connect the two purple
wires to the speaker terminals securely, even though this is tem-
porary, and clip the DCC track power leads (it doesn’t matter
which one) to the red and black wires CAUTION! The orange and
red wires can look very similar – if you connect the orange wire
to track power and turn it on, you will destroy the decoder!
Power-on your DCC controller, and shortly you should hear the
air compressor stroking and some low steam sounds. Assuming
this is a new decoder, select loco address 3 and you may hear
the reverse linkage throw; press the Headlight button and you
should hear the generator crank up. Try the bell and whistle
and advance the throttle a little to hear some exhaust chuffing.
If these functions sound good and nothing is overheating or
smells hot, you can assume the decoder is OK.
Headlight dropping resistors
If you are using 12-volt headlight bulbs, ignore this para-
graph— they won’t need resistors.
If you are using LEDs or
1.5-volt incandescent bulbs, you will need resistors and the
best place (in some small towns, the ONLY place) to get them
is Radio Shack. They make an assortment of 1/4-watt resis-
tors for about $7.00 that will have what you need, or you can
“I use any good silicone RTV, since it holds
well, and the speaker can be removed fairly
easily if it ever needs replacement.”
MRH-Dec 2013
