MTHTrains PENNSYLVANIA K-4s User manual

R
ELECT RIC T R AINS
PENNSYLVANIA K-4s
PACIFIC STEAM ENGINE
OPERATING INSTRUCTIONS
For 2 & 3-Rail Models
Thank you for purchasing the MTH Electric Trains Pennsylvania K-4s Pacific Die-Cast 4-6-2
steam engine. This 1/4" scale reproduction of the famous Pennsy locomotive measures over
32 inches in length and weighs over 16 pounds. Despite its scale size it still operates on
standard O-31 3-rail track with any compatible standard AC transformer, see page 24, and
is completely compatible with most 3-rail locomotives, rolling stock and accessories. If you
purchased the 2-rail version, the engine should negotiate 36 inch radius track and is
compatible with any DC power source.
The 3-rail locomotive and tender are equipped with 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 Operating Instructions found on Page 3 should be read so that you understand the
basics of the operating system. Those features marked for 2 and 3-rail are found in both
versions. Features not marked as such are only available in the 3-rail version.

PRR K-4s 4-6-2 Operating Manual 2
Table Of Contents
QUICK START - BASIC OPERATION (2 and 3-Rail Models) 3
SMOKE UNIT OPERATION 4
PROTOSOUNDS™ OPERATING INSTRUCTIONS 5
DCRU™ REVERSE UNIT OPERATION (All 3-Rail Models) 6
WHISTLE OPERATION 7
BELL OPERATION 7
ENHANCED NEUTRAL STEAM SOUNDS 7
SQUEAKING BRAKE SOUNDS 8
ACTIVATING AND TRIGGERING THE SQUEAKING BRAKE SOUNDS 8
TIPS ON USING THE SQUEAKING BRAKE FEATURE 9
PASSENGER STATION ANNOUNCEMENT (PFA) 9
ACTIVATING AND TRIGGERING PASSENGER ANNOUNCEMENTS 10
TIPS ON USING THE PFA FEATURES 12
PROTO-COUPLER OPERATION 13
SELF-RECHARGING BATTERY BACKUP SYSTEM 13
REPLACING THE PROTOSOUND™ BATTERY 14
PROTOSOUND™ VOLUME ADJUSTMENT 14
USING “RESET" TO PROGRAM PROTOSOUNDS™ 15
ENTERING RESET OPTIONS 15
SETTING THE ENGINE CHUFFING VOLUME 15
PROGRAMMING FOR A SEPARATE BELL BUTTON CONTROLLER 16
PROGRAMMING FOR WHISTLE IN NEUTRAL OPERATION 16
PROGRAMMING FOR PROTOCOUPLER OPERATION 17
PROGRAMMING FOR SQUEAKING BRAKES AND PFA OPERATION 17
ACTIVATING REMOTE LOCK-OUT CONTROL 17
RESETTING ALL PROTOSOUND OPTIONS TO FACTORY DEFAULTS 18
REVERSE UNIT LOCK-OUT OPERATION 19
LOCKING THE ENGINE INTO FORWARD OR REVERSE 19
UNLOCKING THE ENGINE 19
LOCKING THE ENGINE INTO NEUTRAL 19
OIL & LUBRICATION INSTRUCTIONS 20
TRACTION TIRE REPLACEMENT INSTRUCTIONS 21
LIGHT BULB & SMOKE UNIT REMOVAL & REPLACEMENT 21
TROUBLE SHOOTING PROTOSOUND™ PROBLEMS 22
TRANSFORMER COMPATIBILITY AND WIRING CHART 25
PROTOSOUND RESET FEATURE CHART 26
SERVICE AND WARRANTY INFORMATION 27
HOW TO GET SERVICE 27
LIMITED ONE YEAR WARRANTY 27

3 PRR K-4s 4-6-2 Operating Manual
QUICK START - BASIC OPERATION
The MTH Pennsylvania K-4s contains state-of-the-art electronics with several built-in
automatic features for incredibly realistic operation. Despite these advanced features, the K-
4s is easy to operate with any compatible standard AC transformer. (See the compatiblity
chart on page 25) The 2-rail model will operate with any DC power supply. All models are
equipped with an operating smoke system that must be primed with smoke fluid before
operating. Adding 10 - 15 drops of fluid through the smoke stack should be sufficient. If
you choose not to prime the unit with fluid, turn the smoke unit switch located
under the locomotive trailing truck to the OFF position (see Figure 2 on page 4).
This will prevent any damage from occurring to the smoke unit when running the engine
without a primed smoke unit. See the section on page 4 on Smoke Unit operation for more
information.
All 3-rail models are controlled by a DCRU™ reverse unit as part of the MTH ProtoSound™
package. The reverse unit operates in the same manner that all reverse units function by
using forward, neutral and reverse states that are entered by turning the transformer throttle
on and off or by pressing the transformer direction switch (if so equipped). The 2-rail models’
direction is controlled through the polarity of the DC power source and operate the same as
all 2-rail DC engines. 2-Rail engines are
NOT equipped with ProtoSound.
The reverse unit is designed to ignore dirty
track, dead spots on switches or minor short
circuits without disrupting 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 will come on
and two dings from the sound system will
chime as the steam compressor pumps begin. This is known as the RESET state and is
explained in more detail on Page 6. The DCRU will not power the motor until the throttle is
turned OFF and then ON again. At this point, the engine will now function like any other
electronic or mechanical E-Unit. The steam engine chuffing will begin as the engine moves
and the whistle can be blown just as any normal whistle is activated by pressing the whistle
button on your transformer. See the sections later in this guide beginning on Page 7 for more
information on activating the whistle and bell sounds.
Finally, we recommend lubricating your engine before operating it to prevent any
squeaking. See the lubrication directions on Page 20.
Plug Tender Plug Into
Boiler Socket At Back Of Cab
F igure 1: Plugging In The Tender Harness

PRR K-4s 4-6-2 Operating Manual 4
SMOKE UNIT OPERATION
The K-4s contains a self-powered smoke units that output a steady stream of smoke through
the smoke stack. The ON/OFF switch located next to the locomotive trailing truck must be in
the ON position in order for the smoke unit to function. See Fig. 2.
Smoke Unit
On/Off Switch
Figure 2: Smoke Unit On/Off Switch
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
10 - 15 drops of 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 as indicated in Figure 3. 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.
F igure 3: Adding Smoke Fluid
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.
SMOKE UNIT 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

5 PRR K-4s 4-6-2 Operating Manual
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 as seen in Fig.4. After removing the screws lift the inspection
plate away and inspect the wick. If the wick is darkly discolored and hard, it should be
replaced.
NOTE: Replacement bottles of smoke fluid,
such as LGB or LVTS Fluid are available at most
hobby shops. Replacement smoke unit wicks
Remove these two screws
to remove circuit board
After removing circuit board, smoke unit
assembly slides out of the boiler as indicated
After removing circuit board, smoke unit
assembly slides out of the boiler as indicated
(Capacitor)
Figure 4: Removing The Smoke Unit
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 articulated
steam CD-equivalent, 16-bit digital sounds, you get the following features, each of which is
further described on the following pages. Every feature is easily and remotely controlled
from any compatible AC transformer equipped with a whistle button. See the chart on page
25 for a list of compatible transformers.
Built-In DCRU Reverse Unit
Authentic Articulated Bell &Whistle
Enhanced Neutral Steam Sounds
Squeaking Brake Sounds
Passenger Station Announcements
Remote Controlled ProtoCoupler
Self-Recharging Battery Back-Up System
Remotely Controlled Reverse Unit
Remotely Activated Lock-Out
Remotely Adjustable Steam Chuff
Volume
Upgradeable Microprocessor Options
Smoke Unit
Circuit Board
Mounting Screws
Smoke Unit Frame
Mounting Screws
Figure 5: Inspecting the smoke wick

PRR K-4s 4-6-2 Operating Manual 6
DCRU REVERSE UNIT OPERATION
As mentioned in the Basic Operating section, the engine is controlled by a 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 3-5
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 air compressor start up.
In order for ProtoSounds to properly initiate the system check, do not advance the
transformer throttle past 10 volts when you first enter RESET, then wait for the steam
compressor pumps to begin before slowly turning the throttle to the off position and then
back on again to enter the Forward phase. If you enter RESET at too high a voltage, interrupt
the power too soon, or move the throttle too quickly to the off position, the system may reenter
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, remotely activated Proto-
Coupler, Whistle in neutral operation, enhanced neutral steam sounds, squealing brakes
and passenger station announcement sounds. Each of these features are described in more
detail later and all can be remotely activated from any compatible standard AC transformer
with a whistle button (See the chart on page 25). (Additional features will be available at
additional prices from MTH ProtoSound Electronics) You will notice that when in RESET, your
engine will not respond to the whistle button with a whistle 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 button is pressed. This is because the computer is awaiting
programming instructions from one of the many RESET settings. If you don’t wish to
configure ProtoSounds using any of the programmable features, simply leave RESET at this
time by 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.

7 PRR K-4s 4-6-2 Operating Manual
WHISTLE OPERATION
Your K-4s engine is equipped with a digital recording of an articulated steam engine
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 Neutral or RESET. It can,
however, be configured to operate in Neutral by accessing and programming a RESET
option. See page 16 for information on whistle programming in the section entitled “Using
RESET To Program ProtoSounds" section of this manual.
BELL OPERATION
Your K-4s engine is equipped with a digital recording of an actual steam engine bell. The
bell can be turned on or off when the engine is in Forward, Neutral or Reverse from either of
two procedures; using a bell activation button, like the Lionel® Railsounds™ No. 5906 Bell
Button, or by pressing your transformer whistle button when your engine is in neutral. The
bell will never function continuously in RESET. Once the bell is turned on, it will continue to
ring when the engine is cycled into forward, neutral or reverse until you turn the bell off by
pressing the bell button or by re-entering NEUTRAL and pressing 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 trains, 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 OR OFF WITH A BELL BUTTON
To turn the bell on, turn on power to the track and cycle the engine into Forward, Neutral or
Reverse. Press the bell button to activate the bell sounds. To turn off the bell sounds, press the
bell button a second time. If the bell button doesn’t activate the bell, check that it is correctly
wired up to the track and transformer as indicated in Figure 7 on page 16.
TO TURN THE BELL ON OR OFF WITH A WHISTLE BUTTON
Turn on track power and cycle the engine into the Neutral state. 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. To turn the bell off,
reenter Neutral, setting the transformer voltage at eight volts or less and press the whistle
button. The bell should stop ringing. Remember if you don’t have a separate bell button
controller, you must be in Neutral to turn the bell on or off.
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 times.
This helps to eliminate repetitive and boring sound 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.

PRR K-4s 4-6-2 Operating Manual 8
SQUEAKING BRAKE SOUNDS
ProtoSounds is now equipped with operator controlled squeaking brake sounds. Once
activated, this easy to use feature plays the sound of squeaking brakes whenever the
transformer throttle is reduced from high voltage to low voltage simulating the application of
the brakes as you enter curves or slow down for crossings and passenger stations. The sound
itself is a stored record on the ProtoSounds software chip and will always play the same brake
sound for the same 3 second length each time you reduce the voltage from high to low.
ACTIVATING AND TRIGGERING THE SQUEAKING BRAKE SOUNDS
Before the brake squeaking can be heard, ProtoSounds must be activated for the brake
sound feature. The brake sound feature can be activated in 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 squealing brake 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 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 brake sound 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 activate the brake sounds by reducing the
transformer voltage from a high setting to a low setting.
Option 2 If you do not have a separate bell button on your layout, you can still activate the
brake sound feature with your transformer whistle button. To activate the brake 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 brake sound 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 activate the
brake sounds by reducing the transformer voltage from a high setting to a low setting.
Note: Once the brake feature is activated and the engine is running, it is possible that the
brake sounds may not occur if the transformer throttle setting is not set high enough before

9 PRR K-4s 4-6-2 Operating Manual
throttling down. We recommend that after activating the brake feature, you run the engine at
no less than 14 volts before throttling down to approximately 8 volts or less to ensure that the
brake sounds occur.
Note: After activating the brake feature, whenever you stop the engine by either turning the
transformer throttle off or by entering neutral, the brake feature becomes disabled and must
be reactivated using either of the two methods above.
Note: If the brake feature is activated using method number 1 from either forward or reverse
and you interrupt the throttle to enter neutral and leave the throttle on, you may activate
another ProtoSound feature in this engine; Passenger Station Announcement. See the section
later in this manual on Passenger Station Announcement.
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.
PASSENGER STATION ANNOUNCEMENT (PFA)
ProtoSounds is now equipped with operator controlled passenger station announcements,
hereby known as PFA. This easy to use feature plays digitally reproduced passenger station
sounds whenever your engine stops at a train station on your layout. 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 the PFA feature 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 PFA sequence is designed
to simulate the arrival, disembarking, embarking, and departure of a train entering and

PRR K-4s 4-6-2 Operating Manual 10
leaving a train station. The sounds include public address arrival and departure messages,
passenger disembarking and embarking sounds, conductor voices and general train station
ambient sounds. Each is described in more detail in the following sections.
ACTIVATING AND TRIGGERING PASSENGER STATION ANNOUNCEMENTS
Before PFA 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 on page 8.
Once the squealing brake feature is activated, PFA will be played the next time the engine
enters the neutral position. In order for PFA 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 DCRU reverse unit functions by disabling the
reverse unit state during operation of the PFA feature. This forces the engine to leave your
station in the same direction it arrived. The following operator controlled “events” control
PFA’s actions and sounds.
Event 1 (Forward) While the locomotive is running in forward (or reverse) PFA 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 PFA.
Event 2 (Neutral 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 squealing brakes as the engine comes to a stop.
I. Upon stopping of the engine, the operator must immediately turns the throttle back
on as the engine sits in neutral. If the bell was not turned off after activating PFA, it
now turns off automatically.
Note: Failure to turn the throttle back on within 3 seconds of leaving the forward
phase will disable PFA and shutdown ProtoSounds. The next time you turn power back
on your engine will be in the RESET position. See page 6 for more information.
II. After entering neutral, ProtoSounds will immediately play an air release sound
followed approximately two seconds later by an arrival message. The arrival
message lists the train by name and the track it arrived on (the track is identified as
either track 1 or track 2, alternating each time during the current operating session).
Immediately following the arrival message, the sound of the trains’ doors opening
can be heard, followed by a conductor’s warning to passengers to “watch your step.”
At this point, various randomly activated ambient train stations sounds will begin
playing and replaying as long as the engine sits in this neutral state (Neutral Before
Reverse). The sounds include passenger footsteps as they disembark, muffled voices,
baggage being moved about, crashing sound, and whistling for a taxi. In addition,
several highlight or foreground sounds play including more conductor voices saying
“watch your step”, “have a nice day”, and “baggage to the right”.

11 PRR K-4s 4-6-2 Operating Manual
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, PFA has disabled the
reverse phase so that it doesn’t power the motors and cause the engine to move
backward. Upon entering reverse, PFA confirms to the operator that it has entered the
reverse state by immediately playing the highlight sound of the conductor’s voice saying
“baggage to the right.” This is followed by the continued ambient sounds of passenger
footsteps, muffled voices, baggage being moved about, crashing sound and whistling for
a taxi. These sounds and the conductor highlight are randomly repeated as long as the
system remains in the “reverse” state.
Event 4 (Neutral Before Forward) The operator now interrupts the transformer throttle
again to enter the next reverse unit phase; neutral before reverse. PFA confirms to the
operator that it has entered the neutral before forward phase by emmitting two quick air
release sounds. This is followed by a public address message that the train on track 1 or 2
(whichever track number the arriving public address message stated) is now boarding.
Upon completion of the PA message, two conductor voice highlights randomly begin
playing. These conductor voices include “Welcome Aboard” and “Tickets Please”. In
addition to the two conductor highlights, the station ambient sounds continue and still
include passenger footsteps, muffled voices, baggage being moved about, crashing
sound and whistling for a taxi. The departing public address message automatically
repeats itself every 60 seconds with the highlights and station ambient sounds randomly
occurring as long as the system remains in the “neutral before forward” phase.
Event 5. (Forward) The operator now interrupts the transformer throttle again to enter
the next reverse unit phase; forward. PFA confirms to the operator that it has entered the
forward phase by playing a conductor voice yelling “All Aboard!” Immediately after
playing “all aboard”, the sound of the doors closing is heard. Within two seconds of the
doors closing, the locomotive bell begins chiming and the air compressor pumps start.
After approximately 7 chimes of the bell, the engine automatically begins moving out 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 whistle as usual.
Note: When entering the forward phase of PFA, it is important to set the transformer
throttle at a high enough setting that will allow the engine to begin moving once PFA
automatically activates the motors. Otherwise, the engine will just sit still until you
increase the throttle setting on the transformer.

PRR K-4s 4-6-2 Operating Manual 12
TIPS ON USING THE PFA FEATURES
PFA 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 following tips you should
find solutions or suggestions to the various operating scenarios you might encounter when
using PFA.
Tip #1: You can escape the PFA sequence by interrupting the transformer throttle before
the first PA arrival message plays in Event 2 (neutral before reverse).
Tip #2: You can terminate PFA at anytime by turning the transformer throttle off for 15
seconds.
Tip #3: You do not have to be in the forward state to utilize PFA. For example if you
activate the PFA feature while in reverse and interrupt the throttle to enter neutral, you will
be entering neutral before forward rather than neutral before reverse as defined in Event
2 above. Consequently, the forward phase will be rendered inactive by ProtoSounds
instead of the reverse state as explained in Event 3. This will allow your train to leave the
train station in the same reverse direction that it arrived in.
Tip #4: You can utilize PFA even if you are double-heading with another engine,
regardless of whether it is equipped with ProtoSounds or PFA. If the engine isn’t equipped
with PFA, the only thing to remember is that you not turn up the transformer throttle very
high when entering the reverse state 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 engines not equipped with PFA cannot disable the reverse state and
will thus continue powering their own motors. If your second engine is equipped with
PFA, it can be disabled by entering RESET function 28. See the section on programming
RESET functions on page 17 of this manual to disable PFA.
Tip #5: It is not necessary for the squealing brake sounds to be heard to play the PFA
sounds. For example, the brake sounds won’t be heard if the high voltage setting is below
13 volts and 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 affect on PFA until after the PA arrival message has played and the
doors have opened. In Event 5, you cannot interrupt PFA until after the engine begins to
move. Interrupting the throttle before the engine begins to move has no affect on the
locomotive.

13 PRR K-4s 4-6-2 Operating Manual
PROTO-COUPLER OPERATION
Your K-4s locomotive has a coil-wound ProtoCoupler™ mounted on the tender for remote
controlled coupler operation. Because it is controlled through ProtoSound’s microprocessor,
it doesn’t require an uncoupling track section or modification to your layout to function. The
ProtoCoupler can be activated with any compatible standard AC transformer equipped with
a whistle button. For a list of compatible transformers, see the chart on page 25. The three
simple steps below are required to operate the coupler.
A. Put your engine in NEUTRAL and turn the throttle all the way up.
B. Press the whistle button on your transformer to “Arm" the coupler.
C. After arming the coupler, press the whistle button again to open the coupler.
SELF-RECHARGING BATTERY BACKUP SYSTEM
ProtoSounds™ state-of-the-art design includes a self-recharging battery backup system for
improved performance at any speed. There are no switches to turn on or off to enjoy the
benefits of the automatic battery backup system as this feature is automatically activated
whenever track power is turned on. The battery ensures that power to the sound system will
not be interrupted during directional changes, setting RESET options, or when traveling over
dirty track and switches. You will know the backup system is operating as sound will no
longer abruptly shut off whenever a momentary interruption in track power occurs.
ProtoSounds contains a warning alarm if the battery backup system fails to automatically
turn off when power to the track is turned off. You will hear a repeating whistle blast
indicating that the backup system hasn’t turned off. Should this occur, you will need to
unplug the battery from the ProtoSound module to prevent the battery from being run down.
Lubricate
Coupler
Knuckle
Figure 6: Lubricating The Coupler Knuckle
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. 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 or high voltage
settings. 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 coupler
knuckle with light household oil as
indicated in Figure 6.

PRR K-4s 4-6-2 Operating Manual 14
PROTOSOUND™ VOLUME ADJUSTMENT
Your ProtoSound system has two types of volume adjustment. A manual turn knob on the
bottom of the tender chassis (See Fig. 7) allows you to control all the sounds in the system and
a remote control “RESET" option allows you to control the volume level of the steam 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, whistle,
steam chugging sounds, enhanced neutral sounds and others. For instructions on operating
the RESET volume adjustment option, see the section entitled “Programming ProtoSound
Reset Options" on the following pages.
REPLACING THE PROTOSOUND BATTERY
The battery, located in the engine’s tender (see the tender disassembly instructions on
page 20), 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.
(Make sure the smoke unit switch is in the OFF position to prevent harm to the smoke unit)
If you need to replace the ProtoSound™ battery, it is a special NiCad 7-cell, 8.4v battery -
NOT the 6-cell, 7.2v battery found in most convenience stores. The 6-cell NiCad is NOT
recommended for use with ProtoSound™ applications. Replacement ProtoSound™ batteries
are available from MTH ProtoSound Electronics at 9693-A Gerwig Lane, 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
ProtoSound Manual
Volume Adjustment Knob
Figure 7: Adjusting The ProtoSound Volume

15 PRR K-4s 4-6-2 Operating Manual
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 transformer
equipped with a whistle button. For a list of compatible transformers, see the chart on page
25. This hands-off approach gives you unprecedented control of your railroad empire’s
motive power never seen before in model railroading. Each programmable feature can be
accessed whenever your engine is in the RESET state as described in the section entitled
“DCRU Reverse Unit Operation" found earlier on page 6. By following the instructions below
you will find the programming easy and straight forward.
ENTERING RESET OPTIONS
While ProtoSound™ is equipped with only a few programmable features, additional
memory chips can be obtained to “Upgrade" the system in the future. Programmable
features 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 (an optional memory feature that sets an ID
number on your engine), 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 times the throttle is advanced by playing
back the number of “Clinks" and “Clanks" to confirm the feature you’ve selected.
SETTING THE STEAM CHUFFING VOLUME
Of all the sounds that come with each ProtoSound-equipped steam locomotive, the one
most often turned down is that of the steam chuffing 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, turn on your transformer throttle to put the engine in RESET. Move the
throttle up and down as described above 6 times. After you hear the “clank" and “clink"
indicating that you are in Feature 6, press the whistle button to select the steam chuffing
volume level you desire. Pushing the whistle button once will give you full steam chuffing
volume, which is the factory setting. Pushing the whistle button a second time will give you
50% steam chuffing volume, pushing it a third time will give you 25% steam chuffing volume

PRR K-4s 4-6-2 Operating Manual 16
and pushing it a fourth time will give you no steam chuffing sounds. 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 steam chuffing volume setting, the whistle, bell, steam compressor pumps and
enhanced neutral sounds will function normally. In fact because only the steam chuffing
volume is affected by selections in Feature 6, when you select 0 steam chuffing volume, you
will still hear the compressor sounds when the engine is running. Don’t confuse these sounds
with the steam engine chuffing sounds.
PROGRAMMING FOR A SEPARATE BELL BUTTON CONTROLLER
To operate ProtoSounds with a separate
bell button controller, you will need to wire
up the controller to your transformer and
track as per the instructions in Fig. 8.
Once the bell button is wired, you can use
the bell button to activate the bell in
forward, netural or reverse. If the bell
doesn’t operate and is wired up correctly,
you will need to program the ProtoSound
module to operate with a bell button. To
do this, enter RESET and go to Feature 20.
(See the section “Entering RESET Options"
on page 15.) 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 one ding (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. You can also use Feature 18 to reset to its original factory (default) setting
(separate bell button operation).
PROGRAMMING FOR WHISTLE IN NEUTRAL OPERATION
If you want to blow your whistle when your engine is in neutral, you will need to program
ProtoSounds to do so as the factory setting only allows the whistle to blow in forward or
neutral. To do this, enter RESET and go to Feature 25. (See the section entitled “Entering
RESET Options" on page 15). 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 whistle in neutral). Turn the throttle off and then on again to “Lock-In" your
selection. Now, whenever you are in neutral, you can blow the whistle with the transformer
whistle button. To reset ProtoSounds to its original factory setting of no whistle in neutral,
Power Terminal
Wire (black)
Center Rail
Wire (red)
Outside Track
Wire (ground)
F igure 8: Wiring Up A Bell Button Controller

17 PRR K-4s 4-6-2 Operating Manual
repeat the above procedure but keep pressing the whistle button in Feature 25 until
ProtoSounds only dings once instead of twice.
Note:If you didn’t set the “Separate Bell Button Operation" in Feature 20 before setting the
“Whistle In Neutral" option, then your bell will not function until you set the “Separate Bell
Button" option. In addition, when “Whistle In Neutral" is set, the whistle will not sound in
neutral if the transformer throttle setting is over 11 volts. At 11 volts or higher, ProtoSounds
may arm the ProtoCoupler for operation whenever the whistle button is pressed and the
engine is in neutral.
PROGRAMMING FOR PROTOCOUPLER OPERATION
ProtoSounds now comes with a new RESET feature that allows the operator to remotely turn
off the ProtoCoupler coil coupler functions. This is especially useful when double or triple-
heading ProtoSound equipped engines since every engine equipped with a ProtoCoupler
will fire when prompted to by the operator. By turning off the ProtoCoupler operation on
certain engines, you can fire the couplers open on the other engines without uncoupling the
engines from each other. To turn the ProtoCoupler function off, enter RESET and go to
Feature 10. (See the section on “Entering RESET Options" on page 15). Once in Feature 10,
press the transformer whistle button and wait for ProtoSound to sound a bell ding(s).
Continue pressing the whistle button until ProtoSounds sounds two bell dings (signifying that
the ProtoCoupler option has been turned off). Simply turn the transformer throttle off and
then on again to lock in the new setting. To Reset ProtoSounds to its original factory setting of
ProtoCoupler on, repeat the above procedure but keep pressing the whistle button in Feature
10 until ProtoSounds only dings once instead of twice.
PROGRAMMING FOR SQUEAKING BRAKES AND PFA OPERATION
ProtoSounds is equipped with a RESET setting to turn off the Squealing Brakes and
Passenger Station Announcement (PFA) features. This is especially useful if you are double-
heading engines that are both equipped with PFA. You wouldn’t want to stop at a train
station and have both engines initiate their PFA sounds. To turn off Squealing Brakes and
PFA (you cannot turn off one or the other), enter RESET and go to Feature 28. (See the section
on “Entering RESET Options" on page 15). Once in Feature 28, 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 the Squealing Brakes and PFA have
been turned off). Siimply turn the transformer throttle off and then on again to lock in the new
setting. To reset ProtoSounds to its original factory setting of Squealing Brakes and PFA on,
repeat the above procedure but keep pressing the whistle button in Feature 28 until
ProtoSounds only dings once instead of twice.
ACTIVATING REMOTE LOCK-OUT CONTROL
ProtoSound equipped engines feature a RESET setting that allows the operator to remotely
“lock” the engine into forward, neutral or reverse. This is especially useful on layouts that
feature “blocked” track sections. The lockout feature comes from the factory in the OFF

PRR K-4s 4-6-2 Operating Manual 18
position, meaning it is not active when you first take the engine out of the box. This is done to
prevent novice operators from accidentally locking their engines into forward, neutral or
reverse and then mistakingly thinking that the engine’s electronics have failed. To activate
the Remote Lockout Control setting, go to RESET Feature 40 (see the section entitled
“Entering RESET Options” on page 15). Once in Feature 40, press the transformer whistle
button and wait for ProtoSounds to soun a bell ding. Continue pressing the whistle button
until ProtoSounds sounds two bell dings signifying that the Remote Lockout Control has been
selected. To lock in the setting, simply turn the throttle all the way off and then back on again.
To turn the Remote Lockout Control setting back off, go back to Feature 40 and press the
whistle button until only one bell ding sounds. To lock in the setting, simply turn the
transformer throttle off and then back on again. Alternatively, you can go to RESET Feature
18 to reset all ProtoSound Features back to their original factory default settings, including
Remote Lockout Control.
RESETTING ALL PROTOSOUND OPTIONS TO FACTORY DEFAULTS
ProtoSounds is equipped with a RESET feature (Feature 18) that resets all programmable
options back to their original factory settings. This is a useful feature if you find your engine
not operating the way you think it should and don’t want to take the time to check each RESET
Feature one at a time. To reset all the RESET Features back to their original factory settings,
enter RESET and go to Feature 18. (See the section entitled “Entering Reset Options" found
on page 15). Once in Feature 18, press the transformer whistle button and wait for
ProtoSounds to sound a garbled bell sound. Simply turn the transformer throttle off and then
on again to lock in the setting and reset all the options back to their original factory settings.

19 PRR K-4s 4-6-2 Operating Manual
REVERSE UNIT LOCK-OUT OPERATION
ProtoSound’s unique design eliminates the need for a lock-out switch on the locomotive by
allowing the customer to lock the engine into any directional state (forward, neutral or
reverse) from the transformer. This will allow users to run the engine on layouts equipped
with block signals or stop stations which would normally cycle the engine back into neutral.
The feature must be first turned on by accessing RESET Feature 40 (See page 17).
LOCKING THE ENGINE INTO FORWARD OR REVERSE
To lock the engine into Forward or Reverse, use the transformer throttle to enter Forward or
Reverse (whichever state you want to lock the engine into) and while the engine is moving
press the whistle button.
WHILE THE WHISTLE IS BLOWING TURN THE THROTTLE OFF AND THEN LET
GO OF THE WHISTLE BUTTON.
After about one second, you will hear a short horn blast.
QUICKLY TURN THE THROTTLE BACK ON AGAIN. Your engine is now locked into Forward or
Reverse and it will remain so until you unlock the engine, even if you wait a year to run your
engine again.
UNLOCKING THE ENGINE
Unlocking the engine is a similar procedure.
WHILE THE ENGINE IS MOVING, PRESS THE WHISTLE
BUTTON. WHILE THE WHISTLE IS BLOWING, TURN THE THROTTLE OFF AND THEN LET GO OF THE
WHISTLE BUTTON.
After three seconds without power you will hear one chime of the RESET
bell.
TURN ON THE POWER AGAIN. Your engine is now in RESET and will operate normally once
you interrupt power and enter the forward direction.
LOCKING THE ENGINE INTO NEUTRAL
To lock the engine into the NEUTRAL position,
PUT THE ENGINE IN NEUTRAL AND WITH THE
THROTTLE STILL ON, PRESS THE WHISTLE BUTTON. WHILE THE WHISTLE BUTTON IS BEING PRESSED,
TURN OFF THE THROTTLE AND LET GO OF THE WHISTLE BUTTON
.After about one second, you will
hear a short blast of the horn.
QUICKLY TURN THE POWER BACK ON AGAIN. Your engine is now
locked into NEUTRAL.
NOTE:When locking the engine in the Forward or Reverse positions, the whistle button will
blow the horn. But when locking the engine into the NEUTRAL position, the whistle button may
turn on or off sounds of the bell, coupler arming or coupler firing depending on the
transformer throttle voltage settings prior to the user’s attempt to lock out the engine.
Remember, the horn doesn’t blow in NEUTRAL (unless you programmed it to do so using
Feature 25. See page 14 for details), only the bell rings or the coupler operates in NEUTRAL.
While it doesn’t make any difference on how the lockout function operates, you may hear one
of the three different NEUTRAL-activated sounds.
To unlock the engine from the NEUTRAL position, follow the process to unlock the engine in
the Forward or Reverse directions above.

PRR K-4s 4-6-2 Operating Manual 20
OIL & LUBRICATION INSTRUCTIONS (2 & 3-Rail Versions)
In order for the engine to perform correctly and quietly, it is important that both the
locomotive and tender be lubricated before operation. Lubrication should include all side-
rods and linkage components to prevent them from squeaking. Use light household oil and
L
GG
G
G
L
L
F igure 9: Lubricating The Locomotive Chassis
follow the lubrication points marked “L" in Fig. 9 above. In addition to the locomotive, the
tender axles should receive a drop of oil where each axle enters the truck side frame.
The locomotive gearing has been greased at the factory and shouldn’t need additional
grease until after 50 hours of operation or one year whichever comes first. Grease can be
added by inserting grease into the 3 grease pot screw holes (identified by the word “grease")
as seen in Fig. 9 above. Once the screws are removed, grease can be applied into the holes
with a grease tube dispenser. In addition to the gear box gears, it is a good idea to add
grease to the leading and trailing truck mounting areas marked by “G" as shown in Fig. 9.
This will enhance the engine’s ability to run through O-72 “S" curves.
Periodically, check the locomotive and tender wheels for dirt build-up as this can
significantly affect the engine’s ability to perform properly. Dirty track and dirty wheels can
cause both poor electrical contact and poor traction especially on elevated track sections.
Finally, dirt and oil build-up can prematurely wear out the neoprene rubber traction tires.
Tender Body
Mounting Screws
LL
F igure 10: Lubricate The Tender Chassis Trucks Where The Axle Enters The Side Frame