Wednesday, March 30, 2016

Rapido Sound Decoder for the New Haven Athearn Genesis GP-9

A ready To Run New Haven GP-9

This is one of those New Haven only models that fans of the railroad thought they would never see offered in a ready to run low cost plastic model. The New Haven railroad owned several types of equipment that had features that were unique to the railroad therefore offer modeling challenges, the GP-9 was no exception.

As delivered from EMD in 1956 the New Haven GP-9s briefly looked like all other standard GP-9s. The feature that makes them unique are the added water tanks that were installed by the railroad soon after delivery. These dual service locomotives were built with a 800 gallon water storage capacity for the steam generator needed in passenger service but this proved to be an insufficient amount of water. Two additional water tanks were installed, one located on each side behind the cab on the running boards, bringing the total capacity to 1200 gallons.

These water tank additions are easily spotted by the two raised hand rail sections and stanchions behind the cab. This feature can be seen on both sides with the lash-up of two Athearn Genesis New Haven GP-9s below.

Click to enlarge photos

Sound For The GP-9

Although I have operated with DCC for 20 years I am new to sound decoders. Personally, I never cared much in the past for the sound from the early decoders. A sound demonstration of a pre-production Rapido FL-9 at a prototype meet changed that for good. There are now 2 sets of Rapido FL-9s on the layout, they sound and perform very realistically.

A consistent level of detail and performance is personally important to help make this layout a cohesive unit, sound consistency should be no exception. A New Haven GP-9 is powered by an EMD Roots supercharged V16 567-C prime mover and equipped with a steam generator, and a Hancock whistle. For consistency, it is my thinking that the GP-9 should sound the same as a FL-9 that has the same prime mover and equipment.

Rapido Sound Decoder for the Athearn GP-9

Recently acquired Athearn Genesis GP-9s seen above came sound equipped. I do not wish to disparage any manufacture, but I was disappointed that the sound and performance from these decoders were not at a consistent level with the decoders that came installed in the Rapido FL-9.

A check with the Rapido web site confirmed that they offer the FL-9 sound decoder for purchase separately. I chose model # 3100006-8, the decoder comes with the same cell phone type speaker used in their sound equipped FL-9. Below is the Athearn power chassis with factory equipped decoder and speaker and the Rapido decoder package as delivered.

Installing the Decoder

Installing the Rapido decoder and supplied speaker is not difficult and both fit perfectly with the power chassis and body shell. This is not a "plug and play" type of installation so average soldering skills are needed. Below photo compares the factory installed Athearn decoder at top and Rapido decoder installed at the bottom.

The below photo shows the factory decoder and speaker removed, the replacement decoder and speaker are below. The two screws will be retained to hold new speaker in place.

The factory decoder board clips onto a standard bracket above the motor, this bracket is retained to tape the new decoder to. The photo below shows four small holes being drilled thru the front clip, these holes will act as a wire loom for the right and left rail power pick up wires and the two wires that connect the motor to the decoder.

The rear clip is removed to make clearance for the decoder wires. Note that the red wire seen in this photo and the one above is the positive motor wire. The black wire that looks like it may be soldered to the same lug on the motor IS NOT! Dumb photographers mistake, the black wire is the right rail pick up wire from the front truck and just actually dangling in space in these photos.

This next photo shows that a length of wire long enough to reach and splice to the rear pick up wires that come up from the rear truck have been spliced and soldered to the pick up wires that come from the front truck. The splices have been covered with shrink tube then the wires run thru the previously drilled holes to secure them in place. The black motor wire (aka left or negative motor wire) is now also secured thru a hole. The red motor wire mentioned in the last photo has been removed from the soldering lug, the appropriate wire from the decoder will be soldered directly to this lug.

These styrene pieces will be used to secure the new cell phone type speaker in place.

The larger piece made from .040" styrene sheet will be used to clamp the speaker in place, it is cut to the width of the original speaker enclosure. The larger two holes are for the screws that will hold it in place on the frame, these holes were drilled by using the original speaker enclosure as a template. The smaller two holes will be a wire looms for the rear pick up wires.

The smaller styrene piece with the four holes will be glued the larger piece in the next step, it will serve as a wire loom for the speaker wires and front and rear headlight wires. This piece is made from .080" x .125" strip styrene.

The shim is made from .020" x .250" strip styrene and will shim the speaker up to afford a little more clearance between the speaker and rear flywheel.

In this photo the wire loom has been glued to the larger or clamp piece.

The shim has been glued to the frame between the two mounting lugs for the speaker, ACC was used.

The speaker sits on top of the shim.

Now the speaker is secured in place with the styrene clamp using the original screws. The right and left pick up wires from the rear truck are run thru their respective holes.

The right side motor wire from the decoder is run thru the remaining hole that was drilled in the beginning and then soldered to the motor. It is best to hook up this wire first.

The right front pick up wire with extension, the right rear pick up wire and the right rail wire from the decoder come together in a three way splice, then soldered together and the splice is covered with shrink tube.

The same three way splice is made to the left pick up wires and left rail wire from the decoder. The photo below shows that the left motor wire has also been spliced to the appropriate wire from the decoder. The engine is test run without sound at the completion of this step to make sure everything works properly, it does!

Tape is slipped between the original decoder mounting bracket and top of motor sticky side up. Kapton tape is used here. The two motor wires and two front pick up wires will remain on top of the bracket and become neatly secured under the decoder.

Tape is then rapped around decoder and wires securing them to the top of the bracket.

The two speaker wires are run thru the loom,

Then looped around and soldered to the lugs on the speaker. Sound is tested at this step, sounds great!

Then the lugs are covered with shrink tube.

Below is the finished power chassis. In this photo the front and rear headlight wires from the decoder have not been hooked up to the wires that come from from the bulbs that came attached to the body shell. I may change these factory supplied bulbs to longer lasting LEDs at this point while it is still apart.

The body shell will also be weathered appropriately for a one year old locomotive while the shell is not attached to the chassis by the headlight wiring.

As indicated in the photo below make sure the front pickup wires lay in the center of the frame where shown to make clearance for the cab floor. The factory tapes these wires to the frame and can be seen in the first three photos of this post.

The auxiliary wires will not be used and ether coiled up or sniped off before the body shell is put in place.

These locomotives now perform and sound as great as they look, are at the consistent level of performance with the FL-9s on the layout that I was looking for.

The instruction sheet that comes with the decoder has a section called "Awesome Slow Speed Thingy". Make sure to do this simple step, the slow speed performance is truly awesome and the locomotives are perfectly speed matched to one and other.

Rapido and ESU LokSound have a superb product with these decoders, highly recommended.

Just for the record, I am in no way connected to ether company.

1 comment:

  1. Such a nice blog and I appreciate your all efforts about your thoughts. It’s really good work.

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