TIPS & TECHNIQUES
USA F3 Diesels

    Charles Ro (USA Trains) has come out with another "winner" with its
F3 diesels.  These units reflect the EMD 1948 production run, with four
car body filters protected by louvers.  They also come with the larger
number boards, and are identical to the F-7's.  The only real difference
between an F-3 and an F-7 is in the internal electrical systems.  The
later production F-7 units had stainless steel or painted Farr-Air
grills in place of the "chicken wire" of the early units.  Both the F-3
and  F-7 produced 1500 HP and could be geared for either freight or
passenger service.  Some models came with steam generation equipment for
passenger train heat.  The USA units come with this feature, which is
evident by the intake and exhaust stack on the very rear of the diesels
(both A & B units).
    The USA model is a faithful reproduction of this classic locomotive,
and comes in a variety of road names.  The painting and graphics are
excellent, and an A-B-A set is available with different road numbers if
desired by the modeler.  Attention to detail is very high on this model,
including cab interior, coupler lift bars, air hoses, and a full
lighting package   The diesels scale out to 1:29.  The units perform
well together, but I will run connectors between mine to provide full
electrical pickup from all wheels shared by all units.  A major surprise
is that the coupler lift bars and air hoses are already attached to the
locomotives,  thereby eliminating a rather tedious task that I have
performed on earlier USA diesels.
    Both The A and B units have a backup light which works with the
directional lighting system.  When the locomotive backs up, the
headlights shut off and the backup light comes on.  All lighting is
directional, with the classification lights changing color (red/green)
depending upon the direction the locomotive is traveling.  The number
boards and cab interior are also lighted.  Some road names come with two
headlights on the "A" unit.  Prototypically one of these lights was
usually a MARS light (oscillating warning light).  Most roads made the
upper headlight the MARS light so it could be seen at a greater distance
as a warning beacon.  The lower light was a regular headlight, which
being closer to the ground, did an adequate job of illuminating the
tracks.  Prototype practice for a specific road should be checked before
cracking open the shell to change out the headlights.  There are two
diaphragms between the units, which causes the spacing to be  too great
to look prototypical.   I am in the process of figuring out how to
shorten the couplers and diaphragms.  One suggestion from Large Scale
Central was to remove the couplers and install drawbars to shorten the
coupling distance.  You would then remove one diaphragm from between
each unit.  The use of drawbars is prototypical, since many of these
units came this way, and an A-B-A set was counted as one locomotive.
    Caution!! Be very careful when picking up the locomotive, because
the side screens are very thin and fragile and can be destroyed easily.
This caution is included in both the instruction manual and on the box.
The screens and allow a view inside the car body just like the
prototype.  On the real locomotives they were called "chicken wire".
The manufacturer recommends that these units only be picked up by their
ends.

The locomotive is very smooth starting with good speed control.
Pulling power is excellent, and an A-B set should pull a string of
Aristo streamline cars with little trouble.  Gear noise is high, which
seems typical for USA diesels, but I have found that this quiets down
over time.
    Since the USA couplers only work well with other USA rolling stock,
I will change mine.  The Kadee company has instructions for changing the
couplers which is rather involved.  With their permission, I will
re-print it as a separate article. If you run an A-B-A set, you will
have to change  the coupler on the nose of the "A" units.  The dummy
coupler installed by the factory is for show only (dummy), and does not
function.
    A sound system can be easily installed in this unit's fuel tank.
USA has a system available which is manufactured by PH Hobbies.  Sierra
and Phoenix have systems for these diesels that are excellent, and can
be purchased  with both single chime and multiple chime horns.  I will
do a future article on putting a Sierra system into this diesel, along
with putting a MARS light in the nose of the non-sound equipped "A" unit
in my  A-B-A set.  Sierra provides the MARS light option in their sound
system for the sound equipped "A" unit.
    This EMD unit fills a need for large scale railroaders, since it was
a very popular locomotive used by many railroads for both freight and
passenger service.  It is a unit that has long been needed  by members
of the large scale community that run first-generation motive power.