MTHTrains RAILKING SD-45 User manual

RK
AIL ING
By MTH Electric Trains
®
RAILKING SD-45 DIESEL ENGINE
OPERATING INSTRUCTIONS
Thank you for purchasing the RailKing® production of EMD’s SD-45
diesel engine. The engine’s durable ABS body and die-cast trucks are
traditionally sized for operation on any O-31 Gauge track. The engine
should operate for years with any compatible AC transformer (see the chart
on page 35 for a list of compatible transformers) and is completely
compatible with most 3-rail locomotives, rolling stock and accessories.
The locomotive is equipped with either an electronic horn or 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, theQuick Start
Basic Operating Instructions found on Pages 3 and 4 should be read so that
you understand the basics of the operating system. Please note that some
features are only found in the ProtoSound® models and are marked as such.
Features not marked as ProtoSound® features are available in all models.

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SD-45 Diesel Engine Operating Instructions
Table Of Contents
QUICK START - BASIC OPERATION 3
PROTOSOUNDS® OPERATINGINSTRUCTIONS 4
ProtoSound® DCRU® Reverse Unit Operation(All 3-Rail Models) 5
Horn Operation 5
Bell Operation 5
ProtoCoupler™ Operation 6
Squeaking Brake Sounds 7
Tips On Using Squeaking Brakes 8
Freight Yard Sounds (FYS) 9
Tips On Using The Freight Yard Sounds 13
Self-Recharging Battery Backup System 15
Replacing The Battery 15
ProtoSound® Volume Adjustment 16
USING “RESET" TO PROGRAM PROTOSOUNDS® 17
Entering RESET Options 17
Setting The Engine Volume 18
Programming For A Separate Bell Button Controller 19
ProgrammingForSqueakingBrake Operation 19
Programming For Horn In Neutral Operation 20
Programming For Cab Chatter Sounds 21
Programming For ProtoCoupler™ Operation 22
Programming For FYS Operation 22
Activating Reverse Unit Lock-Out Control 23
Resetting All ProtoSound® Options To Factory Defaults 24
Reverse Unit Lockout Control Functions 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 34
Transformer Wiring Chart 35
O-31 OPERATION 36
SERVICE AND WARRANTY INFORMATION 36
HOW TO GET SERVICE 36
LIMITED ONE YEAR WARRANTY 36

3
SD-45 Diesel Engine Operating Instructions
QUICK START - BASIC OPERATION
The RailKing SD-45 contains state-of-the art electronics with several
built-in automatic features for incredibly realistic operation. Despite these
advanced features, the SD-45 is easy to operate with any compatible
standard AC transformer (see the compatibility chart on page 35).
All models are 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. Once the engine is placed
on the track, the throttle on the
transformer can be advanced. You
will see that only the engine’s lights
come on and that only two dings of
the ProtoSound® bell occur
followed by the diesel start-up
sounds (on ProtoSound® equipped 3-rail models). The engine does not run.
This is known as the RESET state
and is explained in more detail
beginning on Page 4. The
ProtoSound® DCRU® will not
power the motors 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. On ProtoSound® equipped engines, the
diesel engine sounds will change in volume as the engine begins to move.
The horn can be activated by pressing the whistle button on the transformer
just as any horn would be activated. See the sections later in this guide,
beginning on page 5, for more information on activating the horn and bell
sounds.
DCRU ®
Lockout Switch
Figure 1: ProtoSound® DCRU® Lockout Switch
RESET
Neutral
Reverse
Neutral
Forward
Figure 2: DCRU™ Cycle Phases

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SD-45 Diesel Engine Operating Instructions
PROTOSOUNDS® OPERATING
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 diesel engine, CD-equivalent 16-bit digital sounds,
you get the following features:
1. ∗Built-In ProtoSound® DCRU® Reverse Unit * Authentic Diesel Engine Horn
Sound * Authentic Diesel Engine 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 Diesel
Engine Volume * Authentic Diesel Engine Start Up & Shut Down Sounds *
Random Selection of Four “Cab Chatter" Radio Transmission Sound Clips *
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

5
SD-45 Diesel Engine Operating Instructions
approximately 2.2 seconds during which you will hear the engine’s startup
sounds begin. In order for ProtoSounds® to properly initiate the system
check, do not advance the transformer throttle past 10 volts when you first
enter RESET, wait for the diesel startup 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
Engine Volume Adjustment, Separate Bell Button Operation
(pre-programmed at the factory), Cab Chatter On/Off Control, ProtoCoupler
On/Off Control and Horn-In-Neutral Operation. 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.
HORN OPERATION
Your RailKing SD-45 ProtoSound® equipped engine is equipped with a
digital recording of a diesel horn. The horn sound can be activated anytime
the engine is in forward or reverse by pressing the whistle button on your
transformer. The horn will continue to blow as long as the whistle button is
depressed. The horn will not function in RESET and must be configured
through a RESET option to allow the horn to work when the engine is in
neutral. See page 17 for information on horn programming in the Using
RESETToProgramProtoSounds® section of this manual.
BELL OPERATION
Your RailKing SD-45 ProtoSound® equipped engine is equipped with a
digital recording of an actual diesel bell. Unlike previous versions of
ProtoSounds®, the bell can be turned on or off with any separate bell
button, like the Lionel® Railsounds® No. 5906 Bell Button, by simply

6
SD-45 Diesel Engine Operating Instructions
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 RailKing SD-45 ProtoSound® equipped locomotive has two
coil-wound ProtoCouplers™ for remote uncoupling action. The couplers
are mounted on the power trucks. 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.
HH
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

7
SD-45 Diesel Engine Operating Instructions
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. 3.
For multiple heading purposes, only one of the two ProtoCouplers™ will
function at any one time. Use the coupler direction switch as shown in Fig.
5 on page 16 to select either the front or rear coupler. Simply slide the
switch toward the direction of the coupler you want to make active.
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 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
Lubricating
The ProtoCoupler®
Figure 3: Lubricating The ProtoCouplers
Throttle Down From
High Voltage To Low
Listen For The
Squeaking Brake Sounds

8
SD-45 Diesel Engine Operating Instructions
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 squealing
sounds as wheel flange sounds, trigger the brake feature using either method 1
or 2 above. Once triggered 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 not release a clear and strong enough DC signal required by
ProtoSounds® computer to play the wheel flange squealing.

9
SD-45 Diesel Engine Operating Instructions
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 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.
ACTIVATING FREIGHT YARD SOUNDS
Your ProtoSounds® 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 neutral position.
ARMING THE FREIGHT YARD FEATURE
Before the 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® No. 5906 bell activation button) you can
activate the feature by pressing and holding the bell button for three seconds
or longer (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 hear an air
release sound after three
seconds have passed at
which time you can
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
Air Release Sound
After 3 Seconds

10
SD-45 Diesel Engine Operating Instructions
release the bell button. (Note: because the air release sound is hard to
hear, we recommend that you count out a full three seconds before
releasing the bell button.) The bell will continue to chime, so if you want to
turn off the bell ringing, simply press and release the bell button a second
time. If you were in neutral when you triggered the brake feature, interrupt
the transformer throttle to enter either forward or reverse to allow the
engine to begin running. (Note: the feature will only be activated in the
first direction state you enter after triggering the feature from the neutral
position. You cannot interrupt the power twice to enter another direction
state and still have the brake feature active.) Once your engine begins
running, you can trigger the sounds to begin playing whenever you enter
neutral.
Option2 If you do not have a separate bell button on your layout, you can
still activate the feature with your transformer whistle button. To activate
the feature turn on the transformer throttle and get your engine into the
neutral position (not RESET). Once in neutral, set the transformer throttle
at 8 volts or less and press and hold the whistle button for at least three
seconds. You will hear the bell chiming turn on and if you listen carefully
you should hear an air release sound after three seconds have passed at
which time you can release the whistle button. (Note: because the air
release sound is hard to hear, we recommend that you count out a full three
seconds before releasing the whistle button.) The bell will continue to
chime, so if you want to turn off the bell ringing, simply press and release
the bell button a second
time. Interrupt the
transformer throttle to enter
either forward or reverse to
allow the engine to begin
running. (Note: the
feature will only be activate
in the first direction state
you enter after triggering
the feature from the neutral position. You cannot interrupt the power twice
to enter another direction state and still have the feature active.) Once your
Put Engine In Neutral
At Low Power
Press & Hold
The Whistle Button
For 3 Seconds
Listen For The
Start Of The Bell Sound
Listen For The
Air Release Sound
After 3 Seconds
H

11
SD-45 Diesel Engine Operating Instructions
engine begins running, you can trigger the sounds to begin by entering
neutral.
ACTIVATING AND TRIGGERING FREIGHT YARD SOUNDS
Before FYS can be heard the feature must be activated first. Activation is
accomplished by holding down the bell button for three or more seconds as
described in the Activating and Triggering The Squeaking Brake Sounds
section found earlier. Once the feature is activated, FYS will be played the
next time the engine enters the neutral position. In order for FYS to begin,
power must remain on once the engine enters the Neutral position. At this
point ProtoSounds® has taken over control of your engine and disabled the
bell and whistle buttons from any further operator functions. In addition,
ProtoSounds® has reconfigured the way the reverse unit functions by
disabling the reverse unit state during operation of the FYS feature. This
forces the engine to leave your freight yard in the same direction it arrived
in. The following operator controlled “events” control FYS’s actions and
sounds.
Event 1 (Forward) While the locomotive is running in forward (or
reverse) FYS is activated by the operator pushing and holding the bell
button down for three or more seconds. The locomotive bell begins
chiming and can be left on or turned off without disabling FYS.
Event 2 (Neural Before Reverse) The operator now interrupts the
transformer throttle to stop the engine and put it into Neutral. If the
throttle setting was at 14 volts or higher , ProtoSounds® will play the
sound of squeaking brake sounds as the engine comes to a halt.
A. Upon stopping of the engine, the
operator must immediately turn the
throttle back on to keep the engine in the
Neutral position. If the bell was not
turned off after activating FYS, it now
turns off automatically.
Put Engine In Neutral
At Low Power

12
SD-45 Diesel Engine Operating Instructions
Note: Failure to turn the throttle back on within 3 seconds of leaving the Forward
phase will disable FYS and shutdown ProtoSounds®. The next time you turn power
back on your engine will be in the RESET position.
See page 4 for more information on RESET.
B. After entering Neutral, ProtoSounds®
will immediately play an air release sound
followed approximately 2 seconds later
by a Cab Chatter Arrival Message. The
arrival message announces what yard the
engine has arrived in (the yard is
described as either Yard A or Yard B,
alternating each time FYS is enabled during the current operating
session. If the engine is turned off for more than three seconds,
ProtoSounds® will automatically return to the Yard A message the
next time FYS is enabled). Immediately following the arrival
message, the sound of freight car doors can be heard opening,
followed by the sounds for forklift engines. At this point various
freight yard sounds can be heard including forklift operation, engine
sounds, reverse warning horn beeps, and additional freight car door sounds.
Event 3: (Reverse) The operator now
interrupts the transformer throttle again to
enter the next reverse unit phase; reverse.
In an effort to enhance realism, FYS has
disabled the reverse phase so that it
doesn’t power the motors causing the
engine to move backward. Upon entering
reverse, FYS confirms to the operator that
it has entered the reverse phase by
immediately playing a highlight sound
best described as a rumbling sound. You may have to go through the entire
FYS sequence several times before you can clearly identify this sound.
After the rumbling highlight is played, the
freight yard sounds heard in Event 2
continue to play randomly.
Event 4: (Neutral Before Forward) The
operator now interrupts the transformer
throttle again to enter the next reverse unit
phase, neutral before forward. FYS
confirms to the operator that it has entered
Listen For Air Release Sound
And Cab Chatter Message
Listen For Engine
Rumbling Sound
Interrupt Throttle To
Enter The Next Phase
Listen For 2
Air Release Sounds
Interrupt Throttle To
Enter The Next Phase

13
SD-45 Diesel Engine Operating Instructions
the neutral before forward phase by emitting two quick air release sounds.
This is followed by a Cab Chatter message that the engine in Yard A or B
(whichever yard designation was played in Event 2) is preparing to depart
the yard. Upon completion of the cab chatter message, the freight yard
sounds change as the forklift sounds turn off and the freight car doors begin
shutting.
Event 5: (Forward) The operator now
interrupts the transformer throttle again to
enter the next reverse unit phase; Forward.
FYS confirms to the operator that it has
entered the Forward phase by playing the
sound of the freight car door closing.
Within 2 seconds of the door closing, the
locomotive bell begins chiming, the diesel
engine sounds come on and the air compressor pumps start. After
approximately 7 chimes of the bell, the engine begins moving in the
forward phase with the bell continuing to ring another 7 chimes before
automatically turning off. Once the bell turns off, the operator regains
control of the transformer whistle and bell buttons and can ring the bell or
blow the horn as usual.
Note: When entering the Forward phase of FYS, it is important to set the
transformer throttle at a high enough setting that will allow the engine to
begin moving once FYS automatically activates the motors. Otherwise the
engine will just sit still until you increase the transformer throttle setting on
the transformer.
TIPS ON USING FYS FEATURES
FYS is a unique feature of ProtoSounds® that is completely controlled by the
operator. You decide how, when or if you want to utilize the feature. By
reviewing the following tips, you should find solutions or suggestions to the
various operating scenarios you might encounter when using FYS.
Tip#1: You can escape the FYS sequence by interrupting the transformer
throttle before the first Cab Chatter message plays in Event 2 (neutral before
reverse).
Tip#2: You can terminate FYS at anytime by turning the transformer throttle
Off for 15 seconds.
Tip#3: You do not have to be in the Forward phase to utilize FYS. For
example, if you activate the FYS feature while in Reverse and interrupt the
throttle to enter Neutral, you will be entering Neutral Before Forward rather
Listen For The Sound
Of Box Door Closing
Interrupt Throttle To
Enter The Next Phase

14
SD-45 Diesel Engine Operating Instructions
than Neutral Before Reverse as defined in Event 2 above. Consequently, the
Forward phase will be rendered inactive by ProtoSounds® instead of the
Reverse phase as explained in Event 3. This will allow your train to leave the
yard in the same reverse direction that it arrived in.
Tip#4: You can utilize FYS even if you are double-heading with another
engine regardless of whether the second engine is equipped with an FYS
programmed ProtoSound® module. If the second engine isn’t equipped with
FYS, the only thing to remember is that you not turn up the transformer
throttle very high when entering the Reverse phase found in Event 3. If the
throttle is set too high, then the second locomotive will begin vibrating on the
track as its motors will be turning in the reverse state since they cannot be
disabled automatically like FYS equipped engines. If your second engine is
equipped with FYS, you may want to disable it when used in double-headed
operations. To disable FYS, see the section on programming RESET
functions on page 28 of this manual.
Tip#5: It is not necessary for the squeaking brake sounds to be heard to play
the FYS sounds. for example, the brake sounds won’t be heard if the high
voltage setting is below 13 volts when the power is interrupted to enter the
Neutral state.
Tip#6: You can leave any of the event states at any time after entering the
state by simply interrupting the transformer throttle. Any sound effects
programmed to play in that event will simply not occur. The only exception
is Event 2 and Event 5. In Event 2, interrupting the throttle has no effect on
FYS until after the arrival Cab Chatter message has completed and the freight
car doors have opened. In Event 5, you cannot interrupt FYS until after the
engine begins to move. Interrupting the throttle before the engine begins to
move has no affect on the locomotive’s operation.

15
SD-45 Diesel Engine Operating Instructions
SELF-RECHARGING BATTERY BACKUP SYSTEM
ProtoSounds® state-of-the-art design includes a self-recharging battery
backup system for improved performance at any speed. The self-recharging
battery backup system is automatically turned on or off whenever track
power is turned on or off. There are no switches to turn on or off to enjoy
the benefits of the automatic battery backup system. The battery ensures
that power to the sound system will remain on during directional changes,
setting RESET options, or when traveling over dirty track and switches.
The battery is a rechargeable NiCad type which is continually charged
from the track when power is applied. NiCad batteries are a dry battery and
should not leak or cause any damage to your locomotive and will last up to
five years or longer. If you notice that the sounds seem distorted or garbled
at low voltages or become silent when power from the transformer is shut
off, the battery may be going bad. Before replacing the battery, you should
put the engine in NEUTRAL and leave the transformer throttle at about 12
volts for fifteen minutes. This should temporarily recharge the battery. If
the garbled or distorted sounds are reduced, then your battery charge has
worn down. You can give your battery a full charge by leaving the engine
ON in NEUTRAL for 16 to 18 hours.
REPLACING THE PROTOSOUND® BATTERY
If you notice that the sounds seem distorted or garbled at low voltages or
become silent when power from the transformer is shut off, the battery may
be going bad. Before replacing the battery, you should put the engine in
NEUTRAL and leave the transformer throttle set at about 12 volts for 15
minutes. This should temporarily recharge the battery. If the garbled or
distorted sounds are reduced, then your battery charge has worn down. You
can give your battery a full charge by leaving the engine ON in the
NEUTRAL position for 18 hours. (Make sure the smoke unit switch is in
the OFF position to prevent harm to the smoke unit wicking).
If you need to replace the battery, replacement ProtoSound® batteries are
available from MTH ProtoSound® Electronics at 7020 Columbia Gateway
Drive, Columbia, MD 21046. A standard 9v alkaline battery can be
substituted as a temporary fix, but since alkaline batteries can’t take a
charge, it will eventually wear down. Regardless, it should give you a week
to a couple of months use while you wait for your replacement
ProtoSound® battery to arrive.

16
SD-45 Diesel Engine Operating Instructions
PROTOSOUND® VOLUME ADJUSTMENT
Your ProtoSound® system has two types of volume adjustment. A
manual turn knob on the bottom of the chassis (See Fig. 4 below) allows
you to control all the sounds in the system and a remote control “RESET"
option (Option # 6), allows you to control the volume level of the engine
sounds remotely from the transformer. Turning the volume adjustment
knob clockwise will increase the volume and counterclockwise will lower
the volume of all sounds; bell, horn, engine sounds, Cab Chatter, etc.
ProtoSounds ®
Volume Control
Figure 4: Adjusting The ProtoSound Volume and
selecting the ProtoCoupler™
ProtoCoupler™
Selection Switch

17
SD-45 Diesel Engine Operating Instructions
USING “RESET" TO PROGRAM
PROTOSOUNDS®
As mentioned earlier, there are several programmable options in each
ProtoSound® equipped engine that can be remotely set from any
compatible standard AC transformer equipped with a whistle button. For a
list of compatible transformers, see the chart on page 35. This hands-off
approach gives you unprecedented control of your railroad empire’s motive
power never before seen in model railroading. Each programmable feature
can be accessed whenever your engine is in the RESET state as described
earlier on page 4. By following the instructions below you will find the
programming easy and straight forward.
ENTERING RESET OPTIONS
ProtoSound® is equipped with a few programmable features that are
accessed in the RESET state by moving the transformer throttle up and
down between full voltage and low voltage (6 to 8 volts) without shutting
the transformer off completely. Each time this is done you advance, one
feature at a time, through the available options. An air-release sound is
heard each time the throttle is advanced. In addition, there are special
sounds to tell you what RESET position you are in.
For example, if you want to select Feature 2, you put the engine in
RESET, and move the throttle up and down from full throttle to low two
times. After the second advance, you will hear two “clinks" indicating that
the computer is now in Feature 2. Advance the throttle again and you will
hear three “clinks" for Feature 3. Advance it two more times and you will
hear a “clank" indicating
that you are now in
Feature 5. Advance the
throttle two more times
and you will hear a
“clank" and two “clinks"
indicating Feature 7. ((5
throttle advancements = 1
clank) + (2 throttle
advancements = 2 clinks)). “Clank + “Clink" + “Clink" = Feature 7. You
can advance the throttle as quickly as you like (though you may not hear the
air-release sounds) and the computer will still remember the number of
In RESET Mode
Move The Throttle
Up & Down From
High Voltage To Low
2 Times
Advance The Throttle
Up & Down From
High Voltage To Low
4 More Times
Listen For The
2 Clink Sounds
Listen For 1 Clank
And 1 Clink Sounds

18
SD-45 Diesel Engine Operating Instructions
times the throttle is advanced by playing back the number of “Clinks" and
“Clanks" to confirm the feature you’ve selected.
SETTING THE ENGINE VOLUME
Of all the sounds that come with each ProtoSound® equipped locomotive,
the one most often turned down is that of the engine volume because it is
the one sound normally heard whenever the engine is running and is what
usually can become tiresome to the ear over prolonged running sessions.
The volume adjustment is controlled through RESET Feature 6.
To access the feature, advance the transformer throttle to put the engine in
RESET. Move the throttle up and down, as described on page 17, 6 times.
After you hear the “clank" and “clink" indicating that you are in Feature 6,
press the whistle button to select the engine volume level you desire.
Pushing the whistle button once will give you full volume, which is the
factory setting. Pushing the whistle button a second time will give you 50%
volume, pushing it a third time will give you 25% volume and pushing it a
fourth time will give you no engine sound. The microprocessor will
immediately play the sound level each time the whistle button is pushed so
that you can decide if it is acceptable. You can recycle through the four
choices by simply
continuing to press the
whistle button.
Once you have decided
on the appropriate
volume level, turn the
transformer throttle off
and on again or press the
transformer direction switch to lock in your selection. The volume
adjustment will remain set at the level you have chosen until you change it
again. Regardless of the engine volume setting, the horn, bell, compressor
and Cab Chatter sounds will function normally. In fact because only the
engine volume is affected by selections in Feature 6, when you select 0
volume, you can still hear the horn, bell and Cab Chatter sounds when the
engine is running or in neutral.
In RESET Mode
Move The Throttle
Up & Down From
High Voltage To Low
6 Times
Listen For 1 Clank
And 1 Clink Sounds
Push The Whistle Button
Until You Reach The
Setting You Desire
Interrupt The Throttle
To “Lock-In”
The Volume Setting
H

19
SD-45 Diesel Engine Operating Instructions
PROGRAMMING FOR A SEPARATE BELL BUTTON
CONTROLLER
To operate ProtoSounds® with
a separate bell button controller,
like the Lionel® No. 5906 bell
button, you will need to wire up
the controller to your
transformer and track as shown
in Fig. 5. Once the button is
wired, ProtoSounds® comes
preprogrammed to allow you to
operate the bell by simply
pushing the bell button once.
To turn the bell off, push the
button again. If the bell doesn’t function when you press the button, you
may need to re-program ProtoSounds to operate with a separate bell button
controller. To do this enter RESET and go to Feature 20. (See the section
Using RESET To Program ProtoSounds®on page 17.) Once in Feature
20, press the whistle button and wait for the module to sound a bell ding(s).
Continue pushing the
whistle button until the
module plays back two
dings (signifying that the
module has been
programmed for a bell
button). Simply turn the
throttle off and then on
again to “Lock-In" the new setting. To reset the computer to its original
factory (default) setting (no separate bell button operation), repeat the above
procedure but keep pushing the whistle button until the computer only
responds with one bell ding.
PROGRAMMING FOR SQUEAKING BRAKE
OPERATION
ProtoSounds® can be programmed for squeaking brake operation in three
different manners; (1)Squeaking brakes can be activated by bell button
control, (2)they can be programmed for continuous operation subject to
throttle changes or (3)they can be programmed to be turned off. The default
setting is (2) Squeaking brakes are activated for full-time operation as
described on page 8. To change the default setting, enter RESET and go to
Common
RED Wire
BLACKWire
U
AU BU CU D
Figure 5: Wiring Up A Bell Button
In RESET Mode
Move The Throttle
Up & Down From
High Voltage To Low
20 Times
Listen For 5 Clank
And 0 Clink Sounds
Push The Whistle Button
Until You Hear 2 Dings
Interrupt The Throttle
To “Lock-In”
The Bell Button Setting
H

20
SD-45 Diesel Engine Operating Instructions
Feature 45. (See the section Using RESET To Program ProtoSounds® on
page 17). Once in Feature 45, press the whistle button and wait for the
module to sound a bell ding(s). Continue pressing the whistle button until
the module plays back one ding for option 1 - Squeaking brakes are
activated by the bell button. Press the whistle button again until the module
plays back two dings for option 2 - squeaking brakes are activated for
full-time operation, or
press the whistle button
again until the module
plays back three dings for
option 3 -Squeaking
brakes off. Once you
have decided on the
desired setting, simply
turn the throttle off and
then on again to “Lock-In” the new setting. To reset the computer to its
original factory default setting (option 2 - squeaking brakes are activated for
full-time operation, repeat the above procedure but keep pushing the whistle
button until the module only responds with one bell ding.
PROGRAMMING FOR HORN IN NEUTRAL
OPERATION
If you are operating your engine with a separate bell button and want to
blow your horn when your engine is in neutral, you will need to program
ProtoSounds® to do so as the factory setting only allows the horn to blow in
forward or reverse. To do this, enter RESET and go to Feature 25. (See the
section Using RESET To Program ProtoSounds® on page 17.) Once in
Feature 25, press the transformer whistle button and wait for ProtoSounds®
to sound a bell ding(s).
Continue pressing the whistle
button until ProtoSounds®
sounds two bell dings
(signifying that
ProtoSounds® has been
programmed to sound the
horn in neutral). Turn the
throttle off and then on again
to “Lock-In" your selection.
In RESET Mode
Move The Throttle
Up & Down From
High Voltage To Low
25Times
Listen For 5 Clank
And 0 Clink Sounds
Push The Whistle Button
Until You Hear
2 Bell Dings
Interrupt The Throttle
To “Lock-In”
The Horn Setting
H
In RESET Mode
Move The Throttle
Up & Down From
High Voltage To Low
45 Times
Listen For 9 Clank
And 0 Clink Sounds
Push The Whistle Button
Until You Hear The
Appropriate # Of Dings
Interrupt The Throttle
To “Lock-In”
The Brake Setting
H