MTHTrains BIG BOY User manual

MTH BIG BOY
ARTICULATED STEAM ENGINE
OPERATING INSTRUCTIONS
Thank you for purchasing the MTH die-cast Big Boy steam locomotive.
The engine’s die-cast body and tender are built to ¼ inch scale proportions
from the original Union Pacific prototype and is designed for operation on
any O-72 or larger O Gauge layout. The engine is compatible with most
standard AC transformers, (see page 34 for a complete list of compatible
transformers and wiring instructions) and is completely compatible with
most other 3-rail locomotives, rolling stock and accessories.
The locomotive and tender are equipped with the ProtoSound® digital
sound and train control system which contains several deluxe features that
are simple and fun to operate. Each feature is described among the
following pages which should be read before the engine is operated. For
those of you who can’t wait to get started, the Quick Start Basic Operating
Instructions found on pages 3 and 4 should be read so that you understand
the basics of the operating system.

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MTH Big Boy Operating Manual
Table Of Contents
QUICK START - BASIC OPERATION(All 3-Rail Models) 3
PROTOSMOKE™ UNIT OPERATION 4
PROTOSOUNDS® OPERATINGINSTRUCTIONS 5
ProtoSound® DCRU® Reverse Unit Operation (All 3-Rail Models) 5
Whistle Operation 6
Bell Operation 6
ProtoCoupler™ Operation 7
Enhanced Neutral Steam Sounds 8
Squeaking Brake Sounds 8
Tips On Using The Squeaking Brake Sounds 9
Freight Yard Sounds (FYS) 10
Activating and Triggering Freight Yard Sounds 10
Tips On Using FYS Features 15
Self-Recharging Battery Backup System 16
Replacing The ProtoSound® Battery 16
ProtoSound® Volume Adjustment 17
USING “RESET" TO PROGRAM PROTOSOUNDS™ 18
Entering RESET Options 18
Setting The Engine Volume 19
Programming For A Separate Bell Button Controller 20
Programming For Squeaking Brake Operation 20
Programming For Whistle In Neutral Operation 21
Programming For ProtoCoupler™ Operation 22
Programming For FYS Operation 23
Activating Remote Lockout Control 23
ResettingAll ProtoSound® Options To Factory Default 24
REVERSE UNIT LOCK-OUT OPERATION 25
Locking The Engine Into Forward or Reverse 25
Unlocking The Engine 25
Locking The Engine Into Neutral 25
OIL & LUBRICATION INSTRUCTIONS 27
TRACTION TIRE REPLACEMENT INSTRUCTIONS 28
LIGHT BULB REMOVAL & REPLACEMENT 29
TROUBLE SHOOTING PROTOSOUND®PROBLEMS 30
ProtoSound® RESET Feature Chart 33
Transformer Wiring Chart 34
SERVICE AND WARRANTY INFORMATION 35
HOW TO GET SERVICE 35
LIMITED ONE YEAR WARRANTY 35

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MTH Big Boy Operating Manual
QUICK START - BASIC OPERATION
The MTH Big Boy contains state-of-the art electronics with several
built-in automatic features for incredibly realistic operation. Despite these
advanced features, the Big Boy is easy to operate with any compatible
standard AC transformer (see the compatibility chart on page 34). All
models are equipped with an operating smoke system that should be primed
with smoke fluid before operating. Adding 15 - 20 drops of fluid through
the smoke stack should be sufficient. If you choose to not prime the units
with fluid, turn the smoke unit switch located under the leading truck to
theOFFposition. (See Figure 1) This will prevent any damage from
occurring to the smoke unit when running the engine without a primed
smoke unit. For more information see the section on page 4 on Smoke Unit
operation.
The Big Boy model is controlled by a
ProtoSound® DCRU® electronic reverse
unit. The reverse unit operates in the same
manner that all reverse units function by
using forward, neutral and reverse states
that are entered each time the throttle is
turned on and off or by using the
transformer direction switch (if so
equipped).
The reverse unit is designed to ignore dirty track, dead spots on switches
or minor short circuits without
disrupting the engine operation,
even at slow, prototypical speeds.
Before the engine can be operated
however, the reverse unit plug that
extends out of the tender must be
inserted into the receptacle at the back of the boiler cab as seen in Figure 1.
Once the plug is inserted, the throttle on the transformer can be advanced.
You will see that only the engine’s lights come on and that on ProtoSound
equipped engines, two dings from the sound system will chime followed by
the steam compressor pump sounds. The engine does not run. This is
known as the RESET state and is explained in more detail beginning on
Page 6. The ProtoSound® DCRU® will not power the motor until the
throttle is turned OFF and then ON again. At this point, the engine will
now function just like any other electronic or mechanical E-unit.
Use first hole for O-72 operation.
Use 2nd hole for display and 96 inch
or larger diameter curves.
Plug Tender Plug into
Boiler Socket at back of cab.
Figure 1: Plugging in the tender harness
RESET
Neutral
Reverse
Neutral
Forward
Figure 2: ProtoSound® DCRU® Cycle Phases

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MTH Big Boy Operating Manual
PROTOSMOKE™ UNIT OPERATION
The Big Boy contains a self-powered smoke unit that outputs a steady stream of smoke
through the smoke stack on the roof of the engine. The ON/OFF switch located next to the
trailing truck must be in the ON position in order for the smoke unit to function. See Fig.
3below.
The smoke unit is essentially a small heating
element and wick which soaks up and then “cooks" a
mineral oil-based fluid that omits a harmless smoke.
The smoke is then forced out of the stack via a small
electric fan which runs at a constant speed. However,
the smoke intensity can be varied by increasing the
transformer voltage setting. The higher the setting,
the more intense the smoke output.
For best results, we recommend that you add 15 -
20 drops of ProtoSmoke™, Seuthe, LGB or LVTS
fluid before you run the engine. If you don’t choose
to add the fluid, then the smoke unit switch should
be turned off. Failure to either add the fluid or turn the switch off could lead to damage to the
smoke unit heating element and or wicking. Add the fluid through the smoke stack hole. After
adding the fluid, gently blow into the stack to eliminate any air bubbles. Do not overfill the
unit as overfilling can cause the fluid to leak out and coat the interior engine components.
When the smoke output begins to diminish while running the engine, an additional 10-15
drops of smoke fluid should be added or the smoke unit switch should be turned off. When
storing the engine for long periods of time, you may want to add at least 15 drops of fluid to
keep the wick soaked with fluid and prevent it from drying out. After removing the engine
from storage, it is advisable to add another 25 drops of fluid, letting the wick soak up the fluid
for 15 minutes prior to operation.
MAINTENANCE
CAUTION: Operating the engine without
smoke fluid and with the smoke unit switch in
the ON position can damage your smoke unit
wick, causing the wick to become hard,
blackened and unabsorbant around the
heating element. When this occurs, it may be
difficult for the wick to soak up the smoke
fluid resulting in poor or no smoke output. If
that occurs, we recommend that you inspect
and/or replace the wick taking care to not
run the engine without fluid in the future.
You can inspect the wick to see if it needs
replacement by removing the smoke unit
inspection cover from the body as seen in
Fig.4. After removing the chassis and inspection cover screws lift the inspection plate away
and inspect the wick. If the wick is darkly discolored and hard, it should be replaced.
Figure 3: Smoke Unit Switch
Figure 4: Inspecting The Smoke Unit

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MTH Big Boy Operating Manual
PROTOSOUNDS® INSTRUCTIONS
The MTH ProtoSound® digital sound and train control system provides
the operator with unprecedented realistic operation on your model railroad.
In addition to actual Big Boy engine, CD-equivalent 16-bit digital sounds,
you get the following features:
1. ∗Built-In ProtoSound® DCRU® Reverse Unit * Authentic Steam Whistle Sound*
Authentic Steam Bell Sound* Squeaking Brake Sound* Freight Yard Sounds*
Operating Remote Controlled ProtoCoupler™* Self-Recharging Battery
Back-Up System With Automatic Battery Shut-Off* Remotely Controlled
Reverse Unit Lock-Out* Remotely Adjustable Steam Engine Chuffing Volume*
Authentic Steam Engine Neutral Sounds*
Each feature is described among the following pages. Though the system
is easy to use, we encourage you to read the instructions thoroughly.
PROTOSOUND® DCRU® REVERSE UNIT
As mentioned in the Basic Operating section, the engine is controlled by a
ProtoSound® DCRU® reverse unit that contains the standard
forward-neutral-reverse states found on most reverse units. However, as
described earlier, when power is first applied to the track, the reverse unit
begins in RESET or what seems like a neutral state. Power must be
interrupted again to get the locomotive to enter the forward state. It is this
first RESET state that gives ProtoSound® its unique, remote controlled
functions. The system will enter RESET whenever power to the track is off
for three or more seconds. NEUTRAL will be referred to as the state
between Forward and Reverse.
ProtoSounds® is equipped with a microprocessor, that, depending on the
amount of memory it is allotted, allows the user to utilize several remotely
activated functions. In the simplest terms, ProtoSounds® has its own
“Computer" controlling these functions. In fact, the power of this
microprocessor is the same as that of a 286 desktop computer! In order to
access many of these remotely controlled functions, the user must be in the
RESET state to do so. RESET is entered anytime power to the locomotive
has been off for more than 3 to 5 seconds. When the engine first enters
RESET, the microprocessor initiates a system check to determine if the
system, transformer and engine are operating correctly. This takes
approximately 2.2 seconds during which you will hear the engine’s
compressor sounds begin. In order for ProtoSounds® to properly initiate

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MTH Big Boy Operating Manual
the system check, do not advance the transformer throttle past 10 volts
when you first enter RESET, wait for the compressor sounds to begin and
then slowly turn the transformer throttle to the off position and then back on
again to enter the forward phase. Interrupting the power too quickly may
cause the system to re-enter RESET (signaled by two dings of the bell).
Should this happen, wait longer before interrupting the power to enter the
Forward phase.
ProtoSounds® comes with several programmable functions, including
remote Steam Chuffing Volume Adjustment, Separate Bell Button
Operation (pre-programmed at the factory), Whistle In Neutral Operation,
ProtoCoupler™ On/Off Control, Squeaking Brakes and Passenger Station
or Freight Yard Proto-Effects. Each of these features are described in more
detail later. You will notice that when in RESET, your engine will not
respond to the whistle button with a horn blast or continuous bell ringing.
In fact, when in RESET and the whistle button is depressed, only one single
bell chime will be heard each time the whistle button is pressed. If you
don’t want to configure or change your locomotive using any of these
programmable features, simply leave RESET and wait 2.2 seconds before
interrupting the power to put the engine in forward. After you leave
RESET, your engine will operate normally in all the direction states of
forward, neutral and reverse. Remember though, once power is turned off
for more than 3 seconds, the next time power is applied to the track, your
engine will be back in RESET.
WHISTLE OPERATION
Your Big Boy ProtoSound® equipped engine is equipped with a digital
recording of a steam whistle. The whistle sound can be activated anytime
the engine is in forward or reverse by pressing the whistle button on your
transformer. The whistle will continue to blow as long as the whistle button
is depressed. The whistle will not function in RESET and must be
configured through a RESET option to allow the whistle to work when the
engine is in neutral. See page 21 for information on whistle programming
in the Using RESET To Program ProtoSounds® section of this manual.
BELL OPERATION
Your Big Boy ProtoSound® equipped engine is equipped with a digital
recording of an actual steam engine bell. The bell can be turned on or off
with any separate bell button, like the Lionel® Railsounds® No. 5906 Bell

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MTH Big Boy Operating Manual
Button, by simply pushing the button. If you don’t have a separate bell
button, the bell can be controlled through your transformer’s whistle button
whenever the engine is in NEUTRAL. The bell will never ring
continuously in RESET (Remember NEUTRAL is the state between
Forward and Reverse). Once the bell is turned on, it will continue to ring
when the engine is cycled into forward or reverse until you press the bell
button or re-enter NEUTRAL and turn the bell off with the whistle button.
In fact, because of ProtoSounds® state-of-the-art design, the
microprocessor remembers its last command. Therefore, unless you turn
the bell off before you quit running your train, the next time you run the
engine, the bell will come on. No matter whether you come back an hour
later or a year later, the bell will begin chiming once the engine enters one
of the three directional states.
To turn the bell on using the transformer’s whistle button, turn on power to
the track and cycle the engine into NEUTRAL. Turn the throttle to 8 volts
or less (any higher voltage will arm the ProtoCoupler™) and press the
whistle button. The bell should begin chiming. To turn the bell off, press
the whistle button again. If you want to keep the bell on while running the
engine, simply interrupt the power with the transformer throttle or the
transformer directional switch and enter forward or reverse.
PROTO-COUPLER® OPERATION
Your Big Boy ProtoSound® equipped locomotive tender is equipped with
a coil-wound ProtoCoupler® for remote uncoupling action. Because the
ProtoCoupler® is controlled through ProtoSounds® microprocessor, it
doesn’t require an uncoupling track section or modification to your layout
to function. The three simple steps below are required to operate the
coupler.
1. Put your engine in NEUTRAL and turn the throttle all the way up.
2. Press the transformer whistle button to “Arm" the coupler. (You
will hear a “Clank").
3. After arming the
coupler, press the whistle
button again to open the
coupler. H H
Put Engine In Neutral
At Full Power
Press & Release
The Whistle Button Press & Release
The Whistle Button
Listen For The
Ca-Clunk Sound
See The Coupler Open
And Listen For The
Cha-Chusshh Sound

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MTH Big Boy Operating Manual
When the knuckle fires open you will hear the buzzing of the coil
energizing and the sound of the air lines coming apart. It can best be
described as a CHA-CHUSHHH sound. The coupler doesn’t have to be
fired in NEUTRAL. Once the
coupler is armed it can be fired
in Forward, Neutral or Reverse.
However, you may find that the
coupler doesn’t open when
firing the coupler at high
speeds. Reduce the voltage
setting on your transformer if
this occurs and run your engine
at a slower speed before firing
the coupler. If the coupler
continues to open erratically, try
lubricating the knuckle with
light oil as indicated in Fig. 5.
ENHANCED NEUTRAL STEAM SOUNDS
The enhanced Neutral Sounds can be automatically heard whenever the
engine is in neutral. The sounds, which include Steam Pop-Off, Steam
Blow-Down, and Steam Injector sounds occur every 2 to 30 seconds. Each
of the three sequences will play at random intervals to eliminate repetitive
and boring sequences. While the sounds are selected to play randomly by
the microprocessor, there is no guarantee that you won’t hear the same
message repeated twice or more times.
SQUEAKING BRAKE SOUNDS
ProtoSound® equipped engines feature the ability to play the sound of
squeaking brakes whenever your engine slows in speed. There are two
settings for activating the squeaking brake sounds. The default setting
allows the brake sounds to play while the engine is in forward or reverse
and the transformer throttle is lowered from a high setting to a low setting
(14 volts to 8 volts or less). The
second setting requires that a bell
button be used to “arm” the
brake feature and is explained in
more detail in the “Activating
Freight Yard Sounds” section
Lubricate
Coupler
Knuckle
Figure 5: Lubricating The ProtoCouplers
Throttle Down From
High Voltage To Low Listen For The
Squeaking Brake Sounds

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MTH Big Boy Operating Manual
found later in this manual. The sound itself is a stored record on the
ProtoSounds® software chip and will always play the same brake sound for
the same three second length each time the voltage is reduced from high to
low. Some practice may be required to synchronize the playing of the brake
sounds with the movement of the engine. It is not uncommon for the engine
to stop before the brake sound is completed. Operators will find that by
coordinating the movement of the throttle setting from 8 volts to off will
allow the engine to maintain its movement while the brake sounds play.
Note: The brake sounds will not be heard if the transformer throttle is not
set above 14 volts and/or not reduced below 8 volts.
TIPS ON USING THE SQUEAKING BRAKE FEATURE
Because the squeaking brake feature always plays for approximately 3
seconds, it is possible that the brake sounds will play longer or shorter than
what visually seems prototypical. You will find that by practicing with the
brake feature, you can quickly determine how quickly to throttle down and
what speeds and voltage settings give you the most prototypical braking effect.
Typical users will find the feature to be a very realistic way to simulate the
sound of an engine slowing down for curves, crossings or coming to a stop at a
station, side track or switch yard. As mentioned above, you will find that
initially your engine may continue to play the brake sounds once your engine
comes to a stop or that the sounds stop prematurely before the engine comes to
a complete halt. For example, if you simply run the engine and turn the throttle
off quickly, the brake sounds will likely continue playing even though the
engine has come to a complete stop. This annoying effect can be eliminated by
simply practicing with the brake feature. In no time, you will quickly learn
how to “feather" the throttle to keep the engine moving while the brake sounds
play and then turning the throttle off just as the sounds stop. Remember that
once you stop the engine, you should turn the throttle to the off position if you
don’t want to activate the Freight Yard Sounds feature described later in this
manual.
The ProtoSound squeaking brake feature also has the ability to simulate the
squeal of wheel flanges when your train enters a curve at high speeds. The
same brake squealing sound plays, but you don’t need to reduce the transformer
throttle to activate the squealing sounds. To play the squeaking sounds as
wheel flange sounds, set the transformer throttle setting at 14 volts or higher.
As your engine enters a curve (or anywhere on the layout) quickly “flick" your
transformer whistle button about half way. This “flicking" action causes the
transformer to release a short DC signal that ProtoSounds reads as an indicator
to activate the brake sounds. The engine won’t slow down even though the
sounds play. This simulates the wheel flange squeal of a train traveling through
a turn too quickly.
Note: Consistent activation of the wheel flange squealing is determined by the
condition of your transformer’s whistle button rectifier disc. Older rectifier
discs may need to be replaced in order to play squeaking sounds.

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MTH Big Boy Operating Manual
FREIGHT YARD SOUNDS (FYS)
ProtoSounds® comes equipped with operator controlled Freight Yard
Sounds, hereby referred to as FYS. This easy to use feature plays digitally
reproduced freight yard sounds whenever your engine stops on your layout
and is parked in the Neutral position. No additional wires or modifications
are needed on your layout to enjoy these amazing sound effects. The
sounds themselves are randomly generated and randomly “shuffled” on the
ProtoSounds® software chip. This gives the system the ability to produce
different sounds in a different order each time FYS is enabled. These
different sounds are heard each time you cycle the transformer throttle from
ON to OFF to ON in the same manner that you would cycle the throttle to
enter the various states of Forward, Neutral and Reverse. The entire FYS
sequence is designed to simulate the arrival, loading or unloading and
departure of a freight train in a freight yard. Each sequence is described in
more detail in the following sections.
ARMING & ACTIVATING FREIGHT YARD SOUNDS
Your ProtoSound® equipped engine features an operator controlled freight
yard sound set. Once activated, this easy-to-use feature plays the sound of
freight yard activities whenever the operator places the engine in the
Neutralposition.
ARMING THE FREIGHT YARD FEATURE
Before freight yard sounds can be heard, ProtoSounds® must activate the
feature so that the next time the engine enters the Neutral position, the
sounds can play. The Feature can be activated one of two ways.
Option 1: If you are using a separate bell button controller to ring your bell
(like the Lionel® Railsounds® number 5906 bell activation button or a
transformer equipped with a bell button, like the MTH Z-4000), you can
activate the Feature by holding down the bell button for three or more
seconds (it doesn’t
matter if you are in
Forward, Neutral or
Reverse). You will hear
the bell chiming turn on
and if you listen
carefully, you should
Put Engine In Neutral,
Forward or Reverse
Press & Hold
The Railsounds® Bell Button
For 3 Seconds
Listen For The
Start Of The Bell Sound
Listen For The
Whistle Blast Sound
After 3 Seconds